Multiplexer, radio frequency module and communication device

Abstract

A multiplexer, a radio frequency module and a communication device. The multiplexer comprises a first port, a first filter, a second filter, a second port and a third port, wherein the first filter comprises a first resonator, the first resonator being connected in series between the first port and the second port, and an input terminal of the first resonator being connected to the first port; and the second filter comprises a second resonator, the second resonator being connected in series between the first port and the third port, and an input terminal of the second resonator being connected to the first port. Because the first resonator of the first filter is connected in series between the first port and the second port and the second resonator of the second filter is connected in series between the first port and the third port, the first resonator and the second resonator are easy to match, such that there is no need to additionally provide a frequency divider or increase matching elements in the multiplexer, and radio frequency signals in a first frequency band can be transmitted through the first filter and radio frequency signals in a second frequency band can be transmitted through the second filter, thereby facilitating the miniaturization of the multiplexer.

Description

Multiplexers, RF modules and communication equipment

[0001] This application claims priority to Chinese Patent Application No. 202510280370.3, filed on March 10, 2025, entitled "Multiplexer, Radio Frequency Module and Communication Equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of wireless communication, and in particular to a multiplexer, a radio frequency module, and a communication device. Background Technology

[0003] In the field of wireless communication, duplexers play a crucial role, enabling simultaneous transmission and reception of signals using different frequency bands. A duplexer has two filters: one for transmitting the signal and the other for receiving the signal. These two filters separate signals of different frequencies, allowing the transmitter and receiver to operate within different frequency ranges, thus achieving simultaneous two-way communication.

[0004] Currently, if the frequency bands of two different frequency bands transmitted and received by a duplexer are close, a frequency divider or additional matching components need to be set in the duplexer, which increases the circuit area of ​​the duplexer and is not conducive to the miniaturization of the duplexer. Summary of the Invention

[0005] This application provides a multiplexer, a radio frequency module, and a communication device, which facilitates device miniaturization and provides stable radio frequency signals.

[0006] In a first aspect, this application provides a multiplexer, which includes a first port, a first filter, a second filter, a second port, and a third port; the first filter is used for filtering a first frequency band, and the first filter includes a first resonator connected in series between the first port and the second port, and the input terminal of the first resonator is connected to the first port; the second filter is used for filtering a second frequency band, the first frequency band being different from the second frequency band, and the second filter includes a second resonator connected in series between the first port and the third port, and the input terminal of the second resonator is connected to the first port.

[0007] In this scheme, since the first resonator of the first filter is connected in series between the first and second ports, and the second resonator of the second filter is connected in series between the first and third ports, the first and second resonators exhibit high admittance (low impedance) in their respective bandpasses and low admittance (high impedance) in each other's bandpasses. The first and second resonators are easily matched, allowing the multiplexer to separate RF signals of different frequency bands through the first and second filters, further enabling the multiplexer to achieve efficient transmission of RF signals of different frequency bands. In the multiplexer provided in this application, it is unnecessary to add a frequency divider or a large number of matching components (such as capacitors or inductors), allowing the RF signal of the first frequency band to pass through the first filter and the RF signal of the second frequency band to pass through the second filter, thus facilitating the miniaturization of the multiplexer.

[0008] In conjunction with the first aspect, in one possible implementation, the admittances of the first resonator and the second resonator are complementary. The first and second resonators exhibit high admittance (low impedance) in their respective bandpasses, and low admittance (high impedance) in each other's bandpasses. The first and second resonators are easily matched, enabling the multiplexer to separate RF signals of different frequency bands through the first and second filters, further facilitating efficient transmission of RF signals of different frequency bands.

[0009] In conjunction with the first aspect, in one possible implementation, the first resonator includes one of the following structures:

[0010] The first resonator includes a first terminal, a second terminal, a first inductor, a first capacitor, and a second capacitor. The first terminals of the first capacitor and the first inductor are both connected to the first terminal. The second terminals of the first capacitor and the first inductor are both connected to the first terminal. The second terminal of the second capacitor is connected to the second terminal. One of the first terminal and the second terminal is connected to the first port, and the other is connected to the second port. When the first terminal is connected to the second port, the second terminal is connected to the first port. The capacitance of the first capacitor and the second capacitor does not exceed 10pF; for example, the capacitance of the first capacitor and the second capacitor can be between 0.01pF and 10pF. The first resonator is composed of three reactive elements (first capacitor, second capacitor, and first inductor). The first resonator has a simple structure and includes a first inductor, enabling it to provide a zero point for the first filter.

[0011] The first resonator includes a first terminal, a second terminal, a first inductor, a first capacitor, and a second capacitor. The first terminal of the first capacitor and the first terminal of the first inductor are both connected to the first terminal. The second terminal of the first inductor is connected to the first terminal of the second capacitor. The second terminal of the first capacitor and the second terminal of the second capacitor are both connected to the second terminal. One of the first terminals is connected to the first port, and the other terminal is connected to the second port. When the first terminal is connected to the second port, the second terminal is connected to the first port.

[0012] The capacitance of the first capacitor and the second capacitor shall not exceed 10pF. For example, the capacitance of the first capacitor and the second capacitor may be between 0.01pF and 10pF.

[0013] The first resonator has a first inductance and is able to provide a zero point for the first filter.

[0014] The first resonator includes a first terminal, a second terminal, a first capacitor, a second capacitor, a first inductor, and a second inductor. The first terminals of the first capacitor and the first inductor are both connected to the first terminal. The second terminals of the first capacitor and the first inductor are both connected to the first terminal. The second terminal of the second capacitor is connected to the first terminal of the second inductor. The second terminal of the second inductor is connected to the second terminal. One of the first terminal and the second terminal is connected to the first port, and the other is connected to the second port. When the first terminal is connected to the first port, the second terminal is connected to the second port. When the first terminal is connected to the second port, the second terminal is connected to the first port. The capacitance of the first capacitor and the second capacitor does not exceed 10 pF; for example, the capacitance of the first capacitor and the second capacitor can be between 0.01 pF and 10 pF. The first resonator, having a first inductor and a second inductor, is capable of providing two zeros for the first filter.

[0015] The first resonator includes a first terminal, a second terminal, a first capacitor, a second capacitor, a first inductor, and a second inductor. A first terminal of the first inductor is connected to the first terminal; a second terminal of the first inductor is connected to both the first terminal and the first terminal of the second inductor; the second terminals of the first and second inductors are jointly connected to the first terminal of the second capacitor; the second terminal of the second capacitor is connected to the second terminal; one of the first and second terminals is connected to the first port, and the other is connected to the second port; when the first terminal is connected to the first port, the second terminal is connected to the second port; when the first terminal is connected to the second port, the second terminal is connected to the first port. The capacitance of the first and second capacitors does not exceed 10 pF; for example, the capacitance of the first and second capacitors can be between 0.01 pF and 10 pF. The first resonator, having both a first and a second inductor, provides two zeros for the first filter.

[0016] The first resonator includes a first terminal, a second terminal, a first capacitor, a second capacitor, a first inductor, and a second inductor. A first terminal of the first inductor is connected to the first terminal. A second terminal of the first inductor is connected to both the first and second terminals of the first and second capacitors. A second terminal of the second inductor is connected to the first terminal of the second capacitor. Both the second terminals of the first and second capacitors are connected to the second terminal. One of the first and second terminals is connected to the first port, and the other is connected to the second port. When the first terminal is connected to the first port, the second terminal is also connected to the second port. When the first terminal is connected to the second port, the second terminal is also connected to the first port. The capacitance of the first and second capacitors does not exceed 10 pF; for example, the capacitance of the first and second capacitors can be between 0.01 pF and 10 pF. The first resonator, with its first and second inductors, provides two zeros for the first filter.

[0017] The first resonator includes a first terminal, a second terminal, a first capacitor, a second capacitor, a first inductor, a second inductor, and a third inductor. A first terminal of the first inductor is connected to the first terminal; a second terminal of the first inductor is connected to the first terminal of the first capacitor and the first terminal of the second inductor; a second terminal of the second inductor is connected to the first terminal of the second capacitor; the second terminal of the second capacitor and the second terminal of the first capacitor are both connected to the first terminal of the third inductor; and the second terminal of the third inductor is connected to the second terminal. One of the first terminal and the second terminal is connected to the first port, and the other is connected to the second port. When the first terminal is connected to the first port, the second terminal is connected to the second port. When the first terminal is connected to the second port, the second terminal is connected to the first port. The capacitance of the first capacitor and the second capacitor does not exceed 10 pF; for example, the capacitance of the first capacitor and the second capacitor can be between 0.01 pF and 10 pF. The first resonator, having a first inductor, a second inductor, and a third inductor, can provide three zeros for the first filter.

[0018] The first resonator includes a first terminal, a second terminal, a first capacitor, a second capacitor, a first inductor, a second inductor, and a third inductor. A first terminal of the first inductor is connected to the first terminal; a second terminal of the first inductor is connected to the first terminal of the first capacitor and the first terminal of the second inductor; the second terminals of the first capacitor and the second inductor are jointly connected to the first terminal of the second capacitor; the second terminal of the second capacitor is connected to the first terminal of the third inductor; and the second terminal of the third inductor is connected to the second terminal. One of the first terminal and the second terminal is connected to the first port, and the other is connected to the second port. When the first terminal is connected to the first port, the second terminal is connected to the second port. When the first terminal is connected to the second port, the second terminal is connected to the first port. The capacitance of the first capacitor and the second capacitor does not exceed 10 pF; for example, the capacitance of the first capacitor and the second capacitor can be between 0.01 pF and 10 pF. The first resonator, having a first inductor, a second inductor, and a third inductor, can provide three zeros for the first filter.

[0019] In conjunction with the first aspect, in one possible implementation, the second resonator includes one of the following structures:

[0020] The second resonator includes a third terminal, a fourth terminal, a fourth inductor, a third capacitor, and a fourth capacitor. The first terminal of the third capacitor and the first terminal of the fourth inductor are both connected to the third terminal. The second terminal of the third capacitor and the second terminal of the fourth inductor are both connected to the first terminal of the fourth capacitor. The second terminal of the fourth capacitor is connected to the fourth terminal. One of the third and fourth terminals is connected to the first port, and the other is connected to the third port. When the third terminal is connected to the first port, the fourth terminal is connected to the third port; when the fourth terminal is connected to the first port, the third terminal is connected to the third port. The capacitances of the third and fourth capacitors do not exceed 10 pF; for example, the capacitances of the third and fourth capacitors can be between 0.01 pF and 10 pF. The second resonator has a fourth inductor and can provide a zero point for the second filter.

[0021] The second resonator includes a third terminal, a fourth terminal, a fourth inductor, a third capacitor, and a fourth capacitor. The first terminals of the third capacitor and the fourth inductor are both connected to the third terminal. The second terminal of the fourth inductor is connected to the first terminal of the fourth capacitor. The second terminals of the third and fourth capacitors are both connected to the fourth terminal. One of the third and fourth terminals is connected to the first port, and the other is connected to the third port. When the third terminal is connected to the first port, the fourth terminal is connected to the third port; when the fourth terminal is connected to the first port, the third terminal is connected to the third port. The capacitances of the third and fourth capacitors do not exceed 10 pF; for example, the capacitances of the third and fourth capacitors can be between 0.01 pF and 10 pF. The second resonator has a fourth inductor and can provide a zero point for the second filter.

[0022] The second resonator includes a third terminal, a fourth terminal, a third capacitor, a fourth capacitor, a fourth inductor, and a fifth inductor. The first terminals of the third capacitor and the fourth inductor are both connected to the third terminal. The second terminals of the third capacitor and the fourth inductor are both connected to the first terminal of the fourth capacitor. The second terminal of the fourth capacitor is connected to the first terminal of the fifth inductor. The second terminal of the fifth inductor is connected to the fourth terminal. One of the third and fourth terminals is connected to the first port, and the other is connected to the third port. When the third terminal is connected to the first port, the fourth terminal is connected to the third port; when the fourth terminal is connected to the first port, the third terminal is connected to the third port. The capacitances of the third and fourth capacitors do not exceed 10 pF; for example, the capacitances of the third and fourth capacitors can be between 0.01 pF and 10 pF. The second resonator, with its fourth and fifth inductors, provides two zeros for the second filter.

[0023] The second resonator includes a third terminal, a fourth terminal, a third capacitor, a fourth capacitor, a fourth inductor, and a fifth inductor. The first terminal of the fourth inductor is connected to the third terminal, and the second terminal of the fourth inductor is connected to the first terminals of both the third and fifth capacitors. The second terminals of the third and fifth capacitors are jointly connected to the first terminal of the fourth capacitor. The second terminal of the fourth capacitor is connected to the fourth terminal. One of the third and fourth terminals is connected to the first port, and the other is connected to the third port. When the third terminal is connected to the first port, the fourth terminal is connected to the third port; when the fourth terminal is connected to the first port, the third terminal is connected to the third port. The capacitances of the third and fourth capacitors do not exceed 10 pF; for example, the capacitances of the third and fourth capacitors can be between 0.01 pF and 10 pF. The second resonator, with its fourth and fifth inductors, provides two zeros for the second filter.

[0024] The second resonator includes a third terminal, a fourth terminal, a third capacitor, a fourth capacitor, a fourth inductor, and a fifth inductor. The first terminal of the fourth inductor is connected to the third terminal, and the second terminal of the fourth inductor is connected to the first terminals of both the third and fifth capacitors. The second terminal of the fifth inductor is also connected to the first terminal of the fourth capacitor. Both the second terminals of the third and fourth capacitors are connected to the fourth terminal. One of the third and fourth terminals is connected to the first port, and the other is connected to the third port. When the third terminal is connected to the first port, the fourth terminal is connected to the third port; conversely, when the fourth terminal is connected to the first port, the third terminal is connected to the third port. The capacitances of the third and fourth capacitors do not exceed 10 pF; for example, their capacitances can be between 0.01 pF and 10 pF. The second resonator, with its fourth and fifth inductors, provides two zeros for the second filter.

[0025] The second resonator includes a third terminal, a fourth terminal, a third capacitor, a fourth capacitor, a fourth inductor, a fifth inductor, and a sixth inductor. The first terminal of the fourth inductor is connected to the third terminal; the second terminal of the fourth inductor is connected to the first terminals of the third and fifth capacitors; the second terminal of the fifth inductor is connected to the first terminal of the fourth capacitor; the second terminals of the fourth and third capacitors are jointly connected to the first terminal of the sixth inductor; and the second terminal of the sixth inductor is connected to the fourth terminal. One of the third and fourth terminals is connected to the first port, and the other is connected to the third port. When the third terminal is connected to the first port, the fourth terminal is connected to the third port; when the fourth terminal is connected to the first port, the third terminal is connected to the third port. The capacitances of the third and fourth capacitors do not exceed 10 pF; for example, the capacitances of the third and fourth capacitors can be between 0.01 pF and 10 pF. The second resonator, with its fourth, fifth, and sixth inductors, provides three zeros for the second filter.

[0026] The second resonator includes a third terminal, a fourth terminal, a third capacitor, a fourth capacitor, a fourth inductor, a fifth inductor, and a sixth inductor. The first terminal of the fourth inductor is connected to the third terminal; the second terminal of the fourth inductor is connected to the first terminals of the third and fifth capacitors; the second terminals of the third and fifth capacitors are jointly connected to the first terminal of the fourth capacitor; the second terminal of the fourth capacitor is connected to the first terminal of the sixth inductor; and the second terminal of the sixth inductor is connected to the fourth terminal. One of the third and fourth terminals is connected to the first port, and the other is connected to the third port. When the third terminal is connected to the first port, the fourth terminal is connected to the third port; when the fourth terminal is connected to the first port, the third terminal is connected to the third port. The capacitances of the third and fourth capacitors do not exceed 10 pF; for example, the capacitances of the third and fourth capacitors can be between 0.01 pF and 10 pF. The second resonator, with its fourth, fifth, and sixth inductors, provides three zeros for the second filter.

[0027] In conjunction with the first aspect, in one possible implementation, the first resonator includes a first terminal, a second terminal, a first inductor, a first capacitor, and a second capacitor. The first terminal of the first capacitor and the first terminal of the first inductor are both connected to the first terminal. The second terminal of the first capacitor and the second terminal of the first inductor are both connected to the first terminal of the second capacitor. The second terminal of the second capacitor is connected to the second terminal. One of the first terminal and the second terminal is connected to the first port, and the other is connected to the second port. The second resonator includes a third terminal, a fourth terminal, a fourth inductor, a third capacitor, and a fourth capacitor. The first terminal of the third capacitor and the first terminal of the fourth inductor are both connected to the third terminal. The second terminal of the third capacitor and the second terminal of the fourth inductor are both connected to the first terminal of the fourth capacitor. The second terminal of the fourth capacitor is connected to the fourth terminal. One of the third terminal and the fourth terminal is connected to the first port, and the other is connected to the third port. The first resonator is connected in series between the first port and the second port, and the second resonator is connected in series between the first port and the third port. The first resonator and the second resonator have the same topology, which is beneficial for achieving admittance matching (admittance complementarity) between the first resonator and the second resonator. The first resonator consists of three reactive components (a first capacitor, a second capacitor, and a first inductor), and provides a zero point for the first filter, enabling the first filter to perform filtering functions in a specific frequency band. The first resonator has a small number of reactive components, a simple topology, and is also conducive to the miniaturization of the multiplexer, reducing its insertion loss. The second resonator also consists of three reactive components (a first capacitor, a second capacitor, and a first inductor), and provides a zero point for the second filter, enabling the second filter to perform filtering functions in a specific frequency band. The second resonator has a small number of reactive components, a simple topology, and is also conducive to the miniaturization of the multiplexer, reducing its insertion loss.

[0028] In conjunction with the first aspect, in one possible implementation, the first filter further includes a third resonator and a fourth resonator. The fourth resonator is connected in series between the first resonator and the second port. The input terminal of the third resonator is connected between the first resonator and the fourth resonator, and the output terminal of the third resonator is grounded. The first filter can be a third-order filter. Third-order filters have fewer reactive components, which helps reduce the insertion loss of the multiplexer. A third-order first filter can provide three zeros. The third resonator can provide one zero for the first filter, and its input terminal is connected between the first and fourth resonators. Its output terminal is grounded. When transmitting radio frequency signals, since the third resonator is not connected in series between the first and second ports, the insertion loss of the first filter during radio frequency signal transmission is reduced.

[0029] In conjunction with the first aspect, in one possible implementation, the first filter further includes a third resonator and a fourth resonator. The input terminal of the third resonator is connected to the output terminal of the first resonator, the output terminal of the third resonator is connected to the input terminal of the fourth resonator, and the output terminal of the fourth resonator is connected to the second port. The first filter can be a third-order filter. Third-order filters have fewer reactive components, which helps to reduce the insertion loss of the multiplexer.

[0030] In conjunction with the first aspect, in one possible implementation, the first filter further includes a third resonator and a fourth resonator. The input terminal of the third resonator is connected to the output terminal of the first resonator, and the output terminal of the third resonator and the input terminal of the fourth resonator are both connected to the second port. The output terminal of the fourth resonator is grounded. The first filter can be a third-order filter. Third-order filters have fewer reactive components, which helps reduce the insertion loss of the multiplexer. The third-order first filter can provide three zeros. The fourth resonator can provide one zero for the first filter, and its input terminal is connected to the output terminal of the third resonator. The output terminal of the fourth resonator is grounded. When transmitting radio frequency signals, since the fourth resonator is not connected in series with the first and second ports, it helps reduce the insertion loss of the first filter when transmitting radio frequency signals.

[0031] In conjunction with the first aspect, in one possible implementation, the third resonator includes one of the following structures:

[0032] The third resonator includes a fifth terminal, a sixth terminal, a seventh inductor, a fifth capacitor, and a sixth capacitor. The first terminal of the fifth capacitor and the first terminal of the seventh inductor are both connected to the fifth terminal. The second terminal of the fifth capacitor and the second terminal of the seventh inductor are both connected to the first terminal of the sixth capacitor. The second terminal of the sixth capacitor is connected to the sixth terminal. One of the fifth and sixth terminals is the input terminal of the third resonator, and the other is the output terminal. The third resonator has a seventh inductor and can provide a zero point for the first filter. The third resonator can be connected in series between the first resonator and the second port. In this case, one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is connected to the second port. In some embodiments, one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is grounded.

[0033] The third resonator includes a fifth terminal, a sixth terminal, a seventh inductor, a fifth capacitor, and a sixth capacitor. The first terminals of the fifth capacitor and the seventh inductor are both connected to the third terminal. The second terminal of the seventh inductor is connected to the first terminal of the sixth capacitor. The second terminals of the fifth and sixth capacitors are both connected to the sixth terminal. One of the fifth and sixth terminals is the input terminal of the third resonator, and the other is its output terminal. The third resonator has a seventh inductor and can provide a zero point for the first filter. The third resonator can be connected in series between the first resonator and the second port. In this case, one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is connected to the second port. In some embodiments, one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is grounded.

[0034] The third resonator includes a fifth terminal, a sixth terminal, a fifth capacitor, a sixth capacitor, a seventh inductor, and an eighth inductor. The first terminals of the fifth capacitor and the seventh inductor are connected to the fifth terminal. The second terminals of the fifth capacitor and the seventh inductor are connected to the first terminal of the sixth capacitor. The second terminal of the sixth capacitor is connected to the first terminal of the eighth inductor, and the second terminal of the eighth inductor is connected to the sixth terminal. One of the fifth and sixth terminals is the input terminal of the third resonator, and the other is the output terminal. The third resonator, with its seventh and eighth inductors, provides two zeros for the first filter. The third resonator can be connected in series between the first resonator and the second port. In this case, one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is connected to the second port. In some embodiments, one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is grounded.

[0035] The third resonator includes a fifth terminal, a sixth terminal, a fifth capacitor, a sixth capacitor, a seventh inductor, and an eighth inductor. The first terminal of the seventh inductor is connected to the fifth terminal, and the second terminal of the seventh inductor is connected to the first terminals of the fifth and eighth capacitors. The second terminals of the fifth and eighth capacitors are jointly connected to the first terminal of the sixth capacitor, and the second terminal of the sixth capacitor is connected to the sixth terminal. One of the fifth and sixth terminals is the input terminal of the third resonator, and the other is the output terminal. The third resonator, with its seventh and eighth inductors, provides two zeros for the first filter. The third resonator can be connected in series between the first resonator and the second port. In this case, one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is connected to the second port. In some embodiments, one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is grounded.

[0036] The third resonator includes a fifth terminal, a sixth terminal, a fifth capacitor, a sixth capacitor, a seventh inductor, and an eighth inductor. The first terminal of the seventh inductor is connected to the fifth terminal, the second terminal of the seventh inductor is connected to the first terminals of the fifth and eighth capacitors, the second terminal of the eighth inductor is connected to the first terminal of the sixth capacitor, and the second terminals of the fifth and sixth capacitors are jointly connected to the sixth terminal. One of the fifth and sixth terminals is the input terminal of the third resonator, and the other is the output terminal. The third resonator, with its seventh and eighth inductors, provides two zeros for the first filter. The third resonator can be connected in series between the first resonator and the second port. In this case, one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is connected to the second port. In some embodiments, one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is grounded.

[0037] The third resonator includes a fifth terminal, a sixth terminal, a fifth capacitor, a sixth capacitor, a seventh inductor, an eighth inductor, and a ninth inductor. The first terminal of the seventh inductor is connected to the fifth terminal; the second terminal of the seventh inductor is connected to the first terminals of the fifth and eighth capacitors; the second terminal of the eighth inductor is connected to the first terminal of the sixth capacitor; the second terminals of the sixth and fifth capacitors are jointly connected to the first terminal of the ninth inductor; and the second terminal of the ninth inductor is connected to the sixth terminal. The third resonator, with its seventh, eighth, and ninth inductors, provides three zeros for the first filter. The third resonator can be connected in series between the first resonator and the second port. In this case, one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is connected to the second port. In some embodiments, one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is grounded.

[0038] The third resonator includes a fifth terminal, a sixth terminal, a fifth capacitor, a sixth capacitor, a seventh inductor, an eighth inductor, and a ninth inductor. The first terminal of the seventh inductor is connected to the fifth terminal; the second terminal of the seventh inductor is connected to the first terminals of the fifth and eighth capacitors; the second terminals of the fifth and eighth capacitors are jointly connected to the first terminal of the sixth capacitor; the second terminal of the sixth capacitor is connected to the first terminal of the ninth inductor; and the second terminal of the ninth inductor is connected to the sixth terminal. One of the fifth and sixth terminals serves as the input terminal of the third resonator, and the other as its output terminal. The third resonator, with its seventh, eighth, and ninth inductors, provides three zeros for the first filter. The third resonator can be connected in series between the first resonator and the second port, in which case one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is connected to the second port. In some embodiments, one of the fifth and sixth terminals is connected to the output terminal of the first resonator, and the other is grounded.

[0039] In conjunction with the first aspect, in one possible implementation, the fourth resonator includes one of the following structures:

[0040] The fourth resonator includes a seventh terminal, an eighth terminal, a tenth inductor, a seventh capacitor, and an eighth capacitor. The first terminal of the seventh capacitor and the first terminal of the tenth inductor are both connected to the seventh terminal. The second terminal of the seventh capacitor and the second terminal of the tenth inductor are both connected to the first terminal of the eighth capacitor. The second terminal of the eighth capacitor is connected to the eighth terminal. One of the seventh and eighth terminals is the input terminal of the fourth resonator, and the other is the output terminal. The fourth resonator has a tenth inductor and can provide a zero point for the first filter. The fourth resonator can be connected in series between the first resonator and the second port. In this case, one of the seventh and eighth terminals is connected to the output terminal of the first or third resonator, and the other is connected to the second port. In some embodiments, the fourth resonator can be connected in parallel with the first resonator; for example, one of the seventh and eighth terminals is connected to the second port, and the other is grounded.

[0041] The fourth resonator includes a seventh terminal, an eighth terminal, a tenth inductor, a seventh capacitor, and an eighth capacitor. The first terminal of the seventh capacitor and the first terminal of the tenth inductor are both connected to the seventh terminal. The second terminal of the tenth inductor is connected to the first terminal of the eighth capacitor. The second terminals of the seventh and eighth capacitors are both connected to the eighth terminal. One of the seventh and eighth terminals is the input terminal of the fourth resonator, and the other is the output terminal. The fourth resonator has a tenth inductor and can provide a zero point for the first filter. The fourth resonator can be connected in series between the first resonator and the second port. In this case, one of the seventh and eighth terminals is connected to the output terminal of the first or third resonator, and the other is connected to the second port. In some embodiments, the fourth resonator can be connected in parallel with the first resonator; for example, one of the seventh and eighth terminals is connected to the second port, and the other is grounded.

[0042] The fourth resonator includes a seventh terminal, an eighth terminal, a seventh capacitor, an eighth capacitor, a tenth inductor, and an eleventh inductor. The first terminals of the seventh and tenth capacitors are connected to the seventh terminal, the second terminals of the seventh and tenth inductors are connected to the first terminal of the eighth capacitor, the second terminal of the eighth capacitor is connected to the first terminal of the eleventh inductor, and the second terminal of the eleventh inductor is connected to the eighth terminal. One of the seventh and eighth terminals is the input terminal of the fourth resonator, and the other is the output terminal. The fourth resonator, with its tenth and eleventh inductors, provides two zeros for the first filter. In one implementation, the fourth resonator can be connected in series between the first and second ports. In this case, one of the seventh and eighth terminals is connected to the output terminal of the first or third resonator, and the other is connected to the second port. In some embodiments, the fourth resonator can be connected in parallel with the first resonator; for example, one of the seventh and eighth terminals is connected to the second port, and the other is grounded.

[0043] The fourth resonator includes a seventh terminal, an eighth terminal, a seventh capacitor, an eighth capacitor, a tenth inductor, and an eleventh inductor. The first terminal of the tenth inductor is connected to the seventh terminal, and the second terminal of the tenth inductor is connected to the first terminals of the seventh and eleventh capacitors. The second terminals of the seventh and eleventh inductors are jointly connected to the first terminal of the eighth capacitor, and the second terminal of the eighth capacitor is connected to the eighth terminal. One of the seventh and eighth terminals is the input terminal of the fourth resonator, and the other is the output terminal. The fourth resonator, having both a tenth and an eleventh inductor, provides two zeros for the first filter. In one implementation, the fourth resonator can be connected in series between the first resonator and the second port. In this case, one of the seventh and eighth terminals is connected to the output terminal of the first or third resonator, and the other is connected to the second port. In some embodiments, the fourth resonator can be connected in parallel with the first resonator; for example, one of the seventh and eighth terminals is connected to the second port, and the other is grounded.

[0044] The fourth resonator includes a seventh terminal, an eighth terminal, a seventh capacitor, an eighth capacitor, a tenth inductor, and an eleventh inductor. The first terminal of the tenth inductor is connected to the seventh terminal, the second terminal of the tenth inductor is connected to the first terminals of the seventh and eleventh capacitors, the second terminal of the eleventh inductor is connected to the first terminal of the eighth capacitor, and the second terminals of the seventh and eighth capacitors are jointly connected to the eighth terminal. One of the seventh and eighth terminals is the input terminal of the fourth resonator, and the other is the output terminal. The fourth resonator, with its tenth and eleventh inductors, provides two zeros for the first filter. In one implementation, the fourth resonator can be connected in series between the first resonator and the second port. In this case, one of the seventh and eighth terminals is connected to the output terminal of the first or third resonator, and the other is connected to the second port. In some embodiments, the fourth resonator can be connected in parallel with the first resonator; for example, one of the seventh and eighth terminals is connected to the second port, and the other is grounded.

[0045] The fourth resonator includes a seventh terminal, an eighth terminal, a seventh capacitor, an eighth capacitor, a tenth inductor, an eleventh inductor, and a twelfth inductor. The first terminal of the tenth inductor is connected to the seventh terminal; the second terminal of the tenth inductor is connected to the first terminals of the seventh and eleventh capacitors; the second terminal of the eleventh inductor is connected to the first terminal of the eighth capacitor; the second terminals of the eighth and seventh capacitors are jointly connected to the first terminal of the twelfth inductor; and the second terminal of the twelfth inductor is connected to the eighth terminal. One of the seventh and eighth terminals is the input terminal of the fourth resonator, and the other is the output terminal. The fourth resonator, with its tenth, eleventh, and twelfth inductors, provides three zeros for the first filter. In one implementation, the fourth resonator can be connected in series between the first and second ports. In this case, one of the seventh and eighth terminals is connected to the output terminal of the first or third resonator, and the other is connected to the second port. In some implementations, the fourth resonator may be connected in parallel with the first resonator; for example, one of the seventh and eighth terminals may be connected to the second port, and the other may be grounded.

[0046] The fourth resonator includes a seventh terminal, an eighth terminal, a seventh capacitor, an eighth capacitor, a tenth inductor, an eleventh inductor, and a twelfth inductor. The first terminal of the tenth inductor is connected to the seventh terminal, the second terminal of the tenth inductor is connected to the first terminals of the seventh and eleventh capacitors, the second terminals of the seventh and eleventh inductors are jointly connected to the first terminal of the eighth capacitor, the second terminal of the eighth capacitor is connected to the first terminal of the twelfth inductor, and the second terminal of the twelfth inductor is connected to the eighth terminal. One of the seventh and eighth terminals is the input terminal of the fourth resonator, and the other is the output terminal. The fourth resonator, with its tenth, eleventh, and twelfth inductors, provides three zeros for the first filter. In one implementation, the fourth resonator can be connected in series between the first and second ports. In this case, one of the seventh and eighth terminals is connected to the output terminal of the first or third resonator, and the other is connected to the second port. In some implementations, the fourth resonator may be connected in parallel with the first resonator; for example, one of the seventh and eighth terminals may be connected to the second port, and the other may be grounded.

[0047] In conjunction with the first aspect, in one possible implementation, the third resonator includes a fifth terminal, a sixth terminal, a seventh inductor, a fifth capacitor, and a sixth capacitor. The first terminal of the fifth capacitor and the first terminal of the seventh inductor are jointly connected to the fifth terminal. The second terminal of the fifth capacitor and the second terminal of the seventh inductor are jointly connected to the first terminal of the sixth capacitor. The second terminal of the sixth capacitor is connected to the sixth terminal. One of the fifth terminal and the sixth terminal is connected to the output terminal of the first resonator, and the other is grounded. The fourth resonator includes a seventh terminal, an eighth terminal, a tenth inductor, a seventh capacitor, and an eighth capacitor. The first terminal of the seventh capacitor and the first terminal of the tenth inductor are jointly connected to the seventh terminal. The second terminal of the seventh capacitor and the second terminal of the tenth inductor are jointly connected to the first terminal of the eighth capacitor. The second terminal of the eighth capacitor is connected to the eighth terminal. One of the seventh terminal and the eighth terminal is connected to the output terminal of the first resonator, and the other is connected to the second port. In the first filter, the first and fourth resonators, which are connected in series, adopt the same topology. This makes it easier to control the admittance of the first filter and is beneficial for its mass production. Since one of the fifth and sixth terminals is connected to the output of the first resonator and the other is grounded, the third resonator can be connected in parallel with the first resonator, which helps reduce insertion loss during RF signal transmission. The third resonator consists of three reactive components (seventh inductor, fifth capacitor, and sixth capacitor), and the fourth resonator consists of three reactive components (tenth inductor, seventh capacitor, and eighth capacitor). The fewer reactive components in the third and fourth resonators help reduce insertion loss in the multiplexer.

[0048] In conjunction with the first aspect, in one possible implementation, the second filter further includes a fifth resonator and a sixth resonator. The sixth resonator is connected in series between the second resonator and the third port. The input terminal of the fifth resonator is connected between the second resonator and the sixth resonator, and the output terminal of the fifth resonator is grounded. The second filter can be a third-order filter. Third-order filters have fewer reactive components, which helps reduce the insertion loss of the multiplexer. The fifth resonator can provide a zero point for the second filter, and since the input terminal of the fifth resonator is connected between the second resonator and the sixth resonator, and the output terminal of the fifth resonator is grounded, the insertion loss of the second filter is reduced when transmitting radio frequency signals because the fifth resonator is not connected in series between the first and third ports. It should be noted that the second filter provided in this application has four zeros. Having more zeros allows the second filter to effectively suppress radio frequency signals outside the second frequency band. The second resonator provides one zero, the fifth resonator provides one zero, and the sixth resonator provides one zero. When the input terminals of the first resonator and the second resonator of the first filter are both connected to the first port, the first filter can form a resonant cavity, providing an additional zero for the second filter. When the input terminals of the first and second resonators of the first and second filters are both connected to the first port, the second filter can also form a resonant cavity, providing an additional zero for the first filter, thus the first filter can also have four zeros. Having more zeros allows the first filter to effectively suppress radio frequency signals outside the first frequency band.

[0049] In conjunction with the first aspect, in one possible implementation, the second filter further includes a fifth resonator and a sixth resonator. The input terminal of the fifth resonator is connected to the output terminal of the second resonator, the output terminal of the fifth resonator is connected to the input terminal of the sixth resonator, and the output terminal of the sixth resonator is connected to the third port. The second filter can be a third-order filter. Third-order filters have fewer reactive components, which helps to reduce the insertion loss of the multiplexer.

[0050] In conjunction with the first aspect, in one possible implementation, the second filter further includes a fifth resonator and a sixth resonator. The input terminal of the fifth resonator is connected to the output terminal of the second resonator, and the output terminal of the fifth resonator and the input terminal of the sixth resonator are both connected to the third port. The output terminal of the sixth resonator is grounded. The second filter can be a third-order filter. Third-order filters have fewer reactive components, which helps reduce the insertion loss of the multiplexer. The third-order second filter has four zeros. The first filter provides one zero for the second filter, and the second, fifth, and sixth resonators each provide one zero for the second filter. The input terminal of the sixth resonator is connected to the output terminal of the fifth resonator, and the output terminal of the sixth resonator is grounded. When transmitting radio frequency signals, since the sixth resonator is not connected in series between the first and third ports, it helps reduce the insertion loss of the second filter during radio frequency signal transmission.

[0051] In conjunction with the first aspect, in one possible implementation, the fifth resonator includes one of the following structures:

[0052] The fifth resonator includes a ninth terminal, a tenth terminal, a thirteenth inductor, a ninth capacitor, and a tenth capacitor. The first terminal of the ninth capacitor and the first terminal of the thirteenth inductor are both connected to the ninth terminal. The second terminal of the ninth capacitor and the second terminal of the thirteenth inductor are both connected to the first terminal of the tenth capacitor. The second terminal of the tenth capacitor is connected to the tenth terminal. One of the ninth terminal and the tenth terminal is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator.

[0053] The fifth resonator includes a ninth terminal, a tenth terminal, a thirteenth inductor, a ninth capacitor, and a tenth capacitor. The first terminal of the ninth capacitor and the first terminal of the thirteenth inductor are both connected to the ninth terminal. The second terminal of the thirteenth inductor is connected to the first terminal of the tenth capacitor. The second terminal of the ninth capacitor and the second terminal of the tenth capacitor are both connected to the tenth terminal. One of the ninth terminal and the tenth terminal is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator.

[0054] The fifth resonator includes a ninth terminal, a tenth terminal, a ninth capacitor, a tenth capacitor, a thirteenth inductor, and a fourteenth inductor; the first terminal of the ninth capacitor and the first terminal of the thirteenth inductor are both connected to the ninth terminal, the second terminal of the ninth capacitor and the second terminal of the thirteenth inductor are both connected to the first terminal of the ninth capacitor, the second terminal of the tenth capacitor is connected to the first terminal of the fourteenth inductor, and the second terminal of the fourteenth inductor is connected to the tenth terminal; one of the ninth terminal and the tenth terminal is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator.

[0055] The fifth resonator includes a ninth terminal, a tenth terminal, a ninth capacitor, a tenth capacitor, a thirteenth inductor, and a fourteenth inductor; the first terminal of the thirteenth inductor is connected to the ninth terminal, the second terminal of the thirteenth inductor is connected to the first terminal of the ninth capacitor and the first terminal of the fourteenth inductor, the second terminals of the ninth capacitor and the fourteenth inductor are jointly connected to the first terminal of the tenth capacitor, and the second terminal of the tenth capacitor is connected to the tenth terminal; one of the ninth terminal and the tenth terminal is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator;

[0056] The fifth resonator includes a ninth terminal, a tenth terminal, a ninth capacitor, a tenth capacitor, a thirteenth inductor, and a fourteenth inductor; the first terminal of the thirteenth inductor is connected to the ninth terminal, the second terminal of the thirteenth inductor is connected to the first terminal of the ninth capacitor and the first terminal of the fourteenth inductor, the second terminal of the fourteenth inductor is connected to the first terminal of the tenth capacitor, and the second terminals of the ninth capacitor and the tenth capacitor are both connected to the tenth terminal; one of the ninth terminal and the tenth terminal is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator.

[0057] The fifth resonator includes a ninth terminal, a tenth terminal, a ninth capacitor, a tenth capacitor, a thirteenth inductor, a fourteenth inductor, and a fifteenth inductor; the first terminal of the thirteenth inductor is connected to the ninth terminal, the second terminal of the thirteenth inductor is connected to the first terminals of the ninth and fourteenth capacitors, the second terminal of the fourteenth inductor is connected to the first terminal of the tenth capacitor, the second terminal of the tenth capacitor and the second terminal of the ninth capacitor are jointly connected to the first terminal of the fifteenth inductor, and the second terminal of the fifteenth inductor is connected to the tenth terminal; one of the ninth and tenth terminals is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator.

[0058] The fifth resonator includes a ninth terminal, a tenth terminal, a ninth capacitor, a tenth capacitor, a thirteenth inductor, a fourteenth inductor, and a fifteenth inductor. The first terminal of the thirteenth inductor is connected to the ninth terminal, the second terminal of the thirteenth inductor is connected to the first terminal of the ninth capacitor and the first terminal of the fourteenth inductor, the second terminals of the ninth capacitor and the fourteenth inductor are jointly connected to the first terminal of the tenth capacitor, the second terminal of the tenth capacitor is connected to the first terminal of the fifteenth inductor, and the second terminal of the fifteenth inductor is connected to the tenth terminal. One of the ninth terminal and the tenth terminal is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator.

[0059] In conjunction with the first aspect, in one possible implementation, the sixth resonator includes one of the following structures:

[0060] The sixth resonator includes an eleventh terminal, a twelfth terminal, a sixteenth inductor, an eleventh capacitor, and a twelfth capacitor. The first terminal of the eleventh capacitor and the first terminal of the sixteenth inductor are both connected to the eleventh terminal. The second terminal of the eleventh capacitor and the second terminal of the sixteenth inductor are both connected to the first terminal of the twelfth capacitor. The second terminal of the twelfth capacitor is connected to the twelfth terminal. One of the eleventh terminal and the twelfth terminal is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator.

[0061] The sixth resonator includes an eleventh terminal, a twelfth terminal, a sixteenth inductor, an eleventh capacitor, and a twelfth capacitor. The first terminal of the eleventh capacitor and the first terminal of the sixteenth inductor are both connected to the eleventh terminal. The second terminal of the sixteenth inductor is connected to the first terminal of the twelfth capacitor. The second terminal of the eleventh capacitor and the second terminal of the twelfth capacitor are both connected to the twelfth terminal. One of the eleventh terminal and the twelfth terminal is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator.

[0062] The sixth resonator includes an eleventh terminal, a twelfth terminal, an eleventh capacitor, a twelfth capacitor, a sixteenth inductor, and a seventeenth inductor; the first terminals of the eleventh capacitor and the sixteenth inductor are connected to the eleventh terminal, the second terminals of the eleventh capacitor and the sixteenth inductor are connected to the first terminal of the eleventh capacitor, the second terminal of the twelfth capacitor is connected to the first terminal of the seventeenth inductor, and the second terminal of the seventeenth inductor is connected to the twelfth terminal; one of the eleventh terminal and the twelfth terminal is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator.

[0063] The sixth resonator includes an eleventh terminal, a twelfth terminal, an eleventh capacitor, a twelfth capacitor, a sixteenth inductor, and a seventeenth inductor; the first terminal of the sixteenth inductor is connected to the eleventh terminal, the second terminal of the sixteenth inductor is connected to the first terminals of the eleventh and seventeenth inductors, the second terminals of the eleventh and seventeenth inductors are jointly connected to the first terminal of the twelfth capacitor, and the second terminal of the twelfth capacitor is connected to the twelfth terminal; one of the eleventh and twelfth terminals is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator.

[0064] The sixth resonator includes an eleventh terminal, a twelfth terminal, an eleventh capacitor, a twelfth capacitor, a sixteenth inductor, and a seventeenth inductor; the first terminal of the sixteenth inductor is connected to the eleventh terminal, the second terminal of the sixteenth inductor is connected to the first terminals of the eleventh and seventeenth capacitors, the second terminal of the seventeenth inductor is connected to the first terminal of the twelfth capacitor, and the second terminals of the eleventh and twelfth capacitors are both connected to the twelfth terminal; one of the eleventh and twelfth terminals is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator.

[0065] The sixth resonator includes an eleventh terminal, a twelfth terminal, an eleventh capacitor, a twelfth capacitor, a sixteenth inductor, a seventeenth inductor, and an eighteenth inductor; the first terminal of the sixteenth inductor is connected to the eleventh terminal, the second terminal of the sixteenth inductor is connected to the first terminals of the eleventh and seventeenth capacitors, the second terminal of the seventeenth inductor is connected to the first terminal of the twelfth capacitor, the second terminal of the twelfth capacitor and the second terminal of the eleventh capacitor are both connected to the first terminal of the eighteenth inductor, and the second terminal of the eighteenth inductor is connected to the twelfth terminal; one of the eleventh and twelfth terminals is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator;

[0066] The sixth resonator includes an eleventh terminal, a twelfth terminal, an eleventh capacitor, a twelfth capacitor, a sixteenth inductor, a seventeenth inductor, and an eighteenth inductor. The first terminal of the sixteenth inductor is connected to the eleventh terminal, the second terminal of the sixteenth inductor is connected to the first terminals of the eleventh and seventeenth capacitors, the second terminals of the eleventh and seventeenth inductors are jointly connected to the first terminal of the twelfth capacitor, the second terminal of the twelfth capacitor is connected to the first terminal of the eighteenth inductor, and the second terminal of the eighteenth inductor is connected to the twelfth terminal. One of the eleventh and twelfth terminals is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator.

[0067] In conjunction with the first aspect, in one possible implementation, the fifth resonator includes a ninth terminal, a tenth terminal, a thirteenth inductor, a ninth capacitor, and a tenth capacitor. The first terminal of the ninth capacitor and the first terminal of the thirteenth inductor are both connected to the ninth terminal. The second terminal of the ninth capacitor and the second terminal of the thirteenth inductor are both connected to the first terminal of the tenth capacitor. The second terminal of the tenth capacitor is connected to the tenth terminal. One of the ninth terminal and the tenth terminal is connected to the output terminal of the second resonator, and the other is grounded. The sixth resonator includes an eleventh terminal, a twelfth terminal, a sixteenth inductor, an eleventh capacitor, and a twelfth capacitor. The first terminal of the eleventh capacitor and the first terminal of the sixteenth inductor are both connected to the eleventh terminal. The second terminal of the eleventh capacitor and the second terminal of the sixteenth inductor are both connected to the first terminal of the twelfth capacitor. The second terminal of the twelfth capacitor is connected to the twelfth terminal. One of the eleventh terminal and the twelfth terminal is connected to the output terminal of the second resonator, and the other is connected to the third port. In the second filter, the second and sixth resonators, connected in series, adopt the same topology. This facilitates control of the admittance of the second filter and is beneficial for its mass production. Since one of the ninth and tenth terminals is connected to the output of the first resonator, and the other is grounded, the fifth resonator can be connected in parallel with the second resonator, which helps reduce insertion loss during RF signal transmission. The second, fifth, and sixth resonators each provide a zero point for the second filter. The topology of the first filter forms a resonant cavity, providing an additional zero point for the second filter.

[0068] In conjunction with the first aspect, in one possible implementation, the first filter further includes a seventh resonator, the input of which is connected between the fourth resonator and the second port, and the output of which is grounded. Adding a seventh resonator to the first filter increases the number of zeros, thereby improving its filtering performance.

[0069] In conjunction with the first aspect, in one possible implementation, the seventh resonator includes a thirteenth terminal, a fourteenth terminal, a thirteenth capacitor, a fourteenth capacitor, a nineteenth inductor, and a twentieth inductor. The first terminal of the nineteenth inductor is connected to the thirteenth terminal, and the second terminal of the nineteenth inductor is connected to the first terminals of the thirteenth and fourteenth capacitors. The second terminal of the twentieth inductor is connected to the first terminal of the fourteenth capacitor. The second terminals of the thirteenth and fourteenth capacitors are jointly connected to the fourteenth terminal. One of the thirteenth and fourteenth terminals is connected between the output terminal of the fourth resonator and the second port, and the other is grounded. Connecting the seventh resonator in parallel with the first resonator reduces the insertion loss of the first filter compared to connecting the seventh resonator in series with the first resonator. The seventh resonator, with its nineteenth and twentieth inductors, provides two zeros for the first filter.

[0070] In conjunction with the first aspect, in one possible implementation, the fifth resonator includes a ninth terminal, a tenth terminal, a ninth capacitor, a tenth capacitor, a thirteenth inductor, and a fourteenth inductor; the first terminal of the thirteenth inductor is connected to the ninth terminal, the second terminal of the thirteenth inductor is connected to the first terminal of the ninth capacitor and the first terminal of the fourteenth inductor, the second terminal of the fourteenth inductor is connected to the first terminal of the tenth capacitor, and the second terminals of the ninth and tenth capacitors are jointly connected to the tenth terminal; one of the ninth and tenth terminals is connected to the output terminal of the second resonator, and the other is grounded; the sixth resonator includes an eleventh terminal, a twelfth terminal, a sixteenth inductor, an eleventh capacitor, and a twelfth capacitor, the first terminal of the eleventh capacitor and the first terminal of the sixteenth inductor are jointly connected to the eleventh terminal, the second terminal of the eleventh capacitor and the second terminal of the sixteenth inductor are jointly connected to the first terminal of the twelfth capacitor, the second terminal of the twelfth capacitor is connected to the twelfth terminal, one of the eleventh and twelfth terminals is connected to the output terminal of the second resonator, and the other is connected to the third port. In the second filter, the second and sixth resonators, connected in series, adopt the same topology. This facilitates control of the second filter's admittance and promotes mass production. Since one of the ninth and tenth terminals is connected to the output of the first resonator, and the other is grounded, the fifth resonator can be connected in parallel with the second resonator, which helps reduce insertion loss during RF signal transmission. The fifth resonator consists of four reactive components (thirteenth inductor, fourteenth inductor, ninth capacitor, and tenth capacitor). The fifth resonator provides two zeros for the second filter, while the second resonator provides one zero. The sixth resonator also provides one zero. The topology of the first filter forms a resonant cavity, providing one zero for the second filter. Connecting the fifth resonator in parallel with the first resonator, compared to connecting them in series, reduces insertion loss. It should be noted that series inductors suppress high-frequency RF signals, which increases insertion loss in the second filter.

[0071] Secondly, this application provides a radio frequency module, the radio frequency module including the multiplexer as described in the first aspect.

[0072] Thirdly, this application provides a communication device, which includes a multiplexer as described in the first aspect or a radio frequency module as described in the second aspect. Attached Figure Description

[0073] Figure 1 is a schematic diagram of a system architecture provided in an embodiment of this application;

[0074] Figure 2 is a schematic diagram of a radio frequency module connected to an antenna according to an embodiment of this application;

[0075] Figure 3 is a schematic diagram of a multiplexer provided in an embodiment of this application;

[0076] Figure 4 is a schematic diagram of the structure of a first resonator provided in an embodiment of this application;

[0077] Figure 5 is a schematic diagram of another first resonator provided in an embodiment of this application;

[0078] Figure 6 is a schematic diagram of the structure of another first resonator provided in an embodiment of this application;

[0079] Figure 7 is a schematic diagram of the structure of another first resonator provided in an embodiment of this application;

[0080] Figure 8 is a schematic diagram of the structure of another first resonator provided in an embodiment of this application;

[0081] Figure 9 is a schematic diagram of the structure of another first resonator provided in an embodiment of this application;

[0082] Figure 10 is a schematic diagram of the structure of another first resonator provided in an embodiment of this application;

[0083] Figure 11 is a schematic diagram of the structure of a second resonator provided in an embodiment of this application;

[0084] Figure 12 is a schematic diagram of another second resonator provided in an embodiment of this application;

[0085] Figure 13 is a schematic diagram of the structure of another second resonator provided in an embodiment of this application;

[0086] Figure 14 is a schematic diagram of the structure of another second resonator provided in an embodiment of this application;

[0087] Figure 15 is a schematic diagram of the structure of another second resonator provided in an embodiment of this application;

[0088] Figure 16 is a schematic diagram of the structure of another second resonator provided in an embodiment of this application;

[0089] Figure 17 is a schematic diagram of the structure of another second resonator provided in an embodiment of this application;

[0090] Figure 18 is a schematic diagram of another multiplexer provided in an embodiment of this application;

[0091] Figure 19 is a schematic diagram of another multiplexer provided in an embodiment of this application;

[0092] Figure 20 is a structural schematic diagram of another multiplexer provided in an embodiment of this application;

[0093] Figure 21 is a schematic diagram of the structure of a third resonator provided in an embodiment of this application;

[0094] Figure 22 is a schematic diagram of another third resonator provided in an embodiment of this application;

[0095] Figure 23 is a schematic diagram of the structure of another third resonator provided in an embodiment of this application;

[0096] Figure 24 is a schematic diagram of the structure of another third resonator provided in an embodiment of this application;

[0097] Figure 25 is a schematic diagram of the structure of another third resonator provided in an embodiment of this application;

[0098] Figure 26 is a schematic diagram of the structure of another third resonator provided in an embodiment of this application;

[0099] Figure 27 is a schematic diagram of the structure of another third resonator provided in an embodiment of this application;

[0100] Figure 28 is a schematic diagram of a fourth resonator provided in an embodiment of this application;

[0101] Figure 29 is a schematic diagram of another fourth resonator provided in an embodiment of this application;

[0102] Figure 30 is a schematic diagram of the structure of another fourth resonator provided in an embodiment of this application;

[0103] Figure 31 is a schematic diagram of the structure of another fourth resonator provided in an embodiment of this application;

[0104] Figure 32 is a schematic diagram of the structure of another fourth resonator provided in an embodiment of this application;

[0105] Figure 33 is a schematic diagram of the structure of another fourth resonator provided in an embodiment of this application;

[0106] Figure 34 is a schematic diagram of the structure of another fourth resonator provided in an embodiment of this application;

[0107] Figure 35 is a schematic diagram of the structure of a fifth resonator provided in an embodiment of this application;

[0108] Figure 36 is a schematic diagram of another fifth resonator provided in an embodiment of this application;

[0109] Figure 37 is a schematic diagram of the structure of another fifth resonator provided in an embodiment of this application;

[0110] Figure 38 is a schematic diagram of the structure of another fifth resonator provided in an embodiment of this application;

[0111] Figure 39 is a schematic diagram of the structure of another fifth resonator provided in an embodiment of this application;

[0112] Figure 40 is a schematic diagram of the structure of another fifth resonator provided in an embodiment of this application;

[0113] Figure 41 is a schematic diagram of the structure of another fifth resonator provided in an embodiment of this application;

[0114] Figure 42 is a schematic diagram of the structure of a sixth resonator provided in an embodiment of this application;

[0115] Figure 43 is a schematic diagram of another sixth resonator provided in an embodiment of this application;

[0116] Figure 44 is a schematic diagram of the structure of another sixth resonator provided in an embodiment of this application;

[0117] Figure 45 is a schematic diagram of the structure of another sixth resonator provided in an embodiment of this application;

[0118] Figure 46 is a schematic diagram of the structure of another sixth resonator provided in an embodiment of this application;

[0119] Figure 47 is a schematic diagram of the structure of another sixth resonator provided in an embodiment of this application;

[0120] Figure 48 is a schematic diagram of the structure of another sixth resonator provided in an embodiment of this application;

[0121] Figure 49 is a graph showing the variation of energy parameters of the multiplexer transmitting radio frequency signals provided in Figure 18.

[0122] Figure 50 is a structural schematic diagram of another multiplexer provided in an embodiment of this application;

[0123] Figure 51 is a structural schematic diagram of another multiplexer provided in an embodiment of this application;

[0124] Figure 52 is a schematic diagram of the multiplexer shown in Figure 51;

[0125] Figure 53 is a schematic diagram of the structure of a seventh resonator provided in an embodiment of this application. Detailed Implementation

[0126] To more clearly illustrate the technical solutions in the embodiments or background art of this application, the application will be further described in detail below with reference to the accompanying drawings.

[0127] Please refer to Figure 1, which shows the system architecture provided in this application. The system architecture may include a base station 10 and a communication device 20. The communication device 20 may be a mobile phone, computer, smart wearable device, router, or other device capable of wireless communication.

[0128] Communication device 20 can search for wireless signals emitted by base station 10 and establish a communication connection with base station 10. After establishing a communication connection, communication device 20 can send wireless signals to base station 10 and can also receive wireless signals sent by base station 10. Base station 10 can also send wireless signals to communication device 20 and can also receive wireless signals sent by communication device 20.

[0129] In some embodiments, referring to FIG2, the communication device 20 may include a radio frequency module 30 and an antenna 40, the antenna 40 being connected to the radio frequency module 30. The radio frequency module 30 may serve as a frontend module (FEM) of the communication device 20.

[0130] When antenna 40 transmits radio frequency (RF) signals, RF module 30 processes the RF signals, including but not limited to amplification, filtering, frequency conversion, and signal switching, thereby providing antenna 40 with RF signals adapted to the frequency band, which antenna 40 then transmits. After antenna 40 receives RF signals, RF module 30 processes the received RF signals, including but not limited to amplification, filtering, frequency conversion, and signal switching, to facilitate subsequent modulation, decoding, and error correction of the received RF signals.

[0131] Referring again to Figure 2, the RF module 30 includes a multiplexer 1000, a switch 50, and a power amplifier (PA) / low-noise amplifier (LNA) 60. Switch 50 controls the connection between the second port 1200 and the antenna 40. When switch 50 connects the second port 1200 and the antenna 40, the RF signal input from the first port 1100 can be transmitted to the antenna 40 after reaching the second port 1200. Switch 50 also controls the connection between the third port 1300 and the antenna 40. When switch 50 connects the third port 1300 and the antenna 40, the RF signal input from the first port 1100 can be transmitted to the antenna 40 after reaching the third port 1300. In the embodiments provided in this application, the multiplexer 1000 is used to realize the multiplexing and transmission of multiple signals on the same transmission medium. The multiplexer 1000 can transmit radio frequency signals of different frequency bands. The multiplexer 1000 can transmit the radio frequency signal of the first frequency band from the first port 1100 to the second port 1200. The multiplexer 1000 can also transmit the radio frequency signal of the second frequency band from the first port 1100 to the third port 1300.

[0132] Referring to Figure 3, the multiplexer 1000 includes a first port 1100, a second port 1200, a third port 1300, a first filter 1400, and a second filter 1500. The first port 1100 is used to connect to the PA / LNA, and the second port 1200 and the third port 1300 are connected to the antenna via switches. The switches can control whether the second port 1200 is connected to or disconnected from the antenna, and the antenna can also control whether the third port 1300 is connected to or disconnected from the antenna.

[0133] The first filter 1400 is used for filtering the first frequency band. The first filter 1400 includes a first resonator 1410, which is connected in series between the first port 1100 and the second port 1200, and the input terminal of the first resonator 1410 is connected to the first port 1100.

[0134] The second filter 1500 is used for filtering the second frequency band. The first frequency band is different from the second frequency band. The second filter 1500 includes a second resonator 1510, which is connected in series between the first port 1100 and the third port 1300, and the input terminal of the second resonator 1510 is connected to the first port 1100.

[0135] In the embodiments provided in this application, since the first resonator 1410 of the first filter 1400 is connected in series between the first port 1100 and the second port 1200, and the second resonator 1510 of the second filter 1500 is connected in series between the first port 1100 and the third port 1300, the first resonator 1410 and the second resonator 1510 exhibit high admittance (low impedance) in their respective bandpasses, and the first resonator 1410 and the second resonator 1510 exhibit low admittance (high impedance) in the other's bandpass.

[0136] The first resonator 1410 and the second resonator 1510 are matched, that is, the admittances of the first resonator 1410 and the second resonator 1510 are complementary, so that the multiplexer 1000 can separate radio frequency signals of different frequency bands through the first filter 1400 and the second filter 1500, and further enable the multiplexer 1000 to achieve efficient transmission of radio frequency signals of different frequency bands.

[0137] For example, when a first frequency band radio frequency signal is input to the first port 1100 of the multiplexer 1000, the first resonator 1410 exhibits high admittance (low impedance), and the second resonator 1510 exhibits low admittance (high impedance). The first resonator 1410 allows the first frequency band signal to pass through, while the second resonator 1510 does not allow the first frequency band radio frequency signal to pass through. At this time, the first frequency band radio frequency signal can reach the second port 1200 from the first port 1100 through the first filter 1400, but cannot reach the third port 1300 from the first port 1100 through the second filter 1500. When a second frequency band radio frequency signal is input to the first port 1100 of the multiplexer 1000, the first resonator 1410 exhibits low admittance (high impedance), and the second resonator 1510 exhibits high admittance (low impedance). The first resonator 1410 does not allow the second frequency band signal to pass through, while the second resonator 1510 allows the second frequency band signal to pass through. At this time, the radio frequency signal of the second frequency band cannot reach the second port 1200 after passing through the first filter 1400 from the first port 1100, but can reach the third port 1300 after passing through the second filter 1500 from the first port 1100.

[0138] For example, when the first port 1100 of the multiplexer 1000 simultaneously receives a first frequency band radio frequency signal and a second frequency band radio frequency signal, the radio frequency signal of the first frequency band input from the first port 1100 passes through the first filter 1400 to reach the second port 1200, and the radio frequency signal of the second frequency band input from the first port 1100 passes through the second filter 1500 to reach the third port 1300. The first filter 1400 can block the radio frequency signal of the second frequency band from reaching the second port 1200 from the first port 1100, and the second filter 1500 can block the radio frequency signal of the first frequency band from reaching the third port 1300 from the first port 1100.

[0139] Since the first resonator 1410 of the first filter 1400 is connected in series between the first port 1100 and the second port 1200, and the second resonator 1510 of the second filter 1500 is connected in series between the first port 1100 and the third port 1300, the admittances of the first resonator 1410 and the second resonator 1510 are more easily matched. In the multiplexer 1000 provided in this application, it is not necessary to add a frequency divider or a large number of matching components (such as capacitors or inductors), so that the radio frequency signal of the first frequency band passes through the first filter 1400 and the radio frequency signal of the second frequency band passes through the second filter 1500, which is conducive to the miniaturization of the multiplexer 1000.

[0140] In the embodiments provided in this application, please refer to Figures 4-10. The first resonator 1410 includes one of the following structures:

[0141] Referring to Figure 4, the first resonator 1410 includes a first terminal 1411a, a second terminal 1412a, a first inductor 1415a, a first capacitor 1413a, and a second capacitor 1414a. The first ends of the first capacitor 1413a and the first inductor 1415a are both connected to the first terminal 1411a. The second ends of the first capacitor 1413a and the first inductor 1415a are both connected to the first end of the second capacitor 1414a. The second end of the second capacitor 1414a is connected to the second terminal 1412a. One of the first terminal 1411a and the second terminal 1412a is connected to the first port 1100, and the other is connected to the second port 1200. When the first terminal 1411a is connected to the first port 1100, the second terminal 1412a is connected to the second port 1200. When the first terminal 1411a is connected to the second port 1200, the second terminal 1412a is connected to the first port 1100.

[0142] The capacitance of the first capacitor 1413a and the second capacitor 1414a does not exceed 10pF. The capacitance of the first capacitor 1413a and the second capacitor 1414a can be between 0.01pF and 10pF. The capacitance of the first capacitor 1413a can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the second capacitor 1414a can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0143] The first resonator 1410 is composed of three reactive components (such as a first capacitor 1413a, a second capacitor 1414a, and a first inductor 1415a). The first resonator 1410 has a simple structure, and it includes a first inductor 1415a. The first resonator 1410 can provide a zero point for the first filter 1400. The inductance value of the first inductor 1415a does not exceed 10nH, and can be between 0.01nH and 10nH. Specifically, the inductance value of the first inductor 1415a can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0144] It should be noted that a zero point refers to the frequency point in the filter's transfer function where the response is zero. That is, at these specific frequencies, the signal's transmission coefficient is zero, and the signal cannot pass through the filter; this is also called a transmission zero. From a frequency domain perspective, at a zero point, the filter completely suppresses signals of the corresponding frequency, manifested as a zero amplitude on the amplitude-frequency response curve at that frequency point.

[0145] Referring to Figure 5, the first resonator 1410 includes a first terminal 1411b, a second terminal 1412b, a first inductor 1415b, a first capacitor 1413b, and a second capacitor 1414b. The first ends of the first capacitor 1413b and the first inductor 1415b are both connected to the first terminal 1411b. The second end of the first inductor 1415b is connected to the first end of the second capacitor 1414b. The second ends of the first capacitor 1413b and the second end of the second capacitor 1414b are both connected to the second terminal 1412b. One of the first terminals 1411b is connected to the first port 1100, and the other is connected to the second port 1200. When the first terminal 1411b is connected to the first port 1100, the second terminal 1412b is connected to the second port 1200. When the first terminal 1411b is connected to the second port 1200, the second terminal 1412b is connected to the first port 1100.

[0146] The capacitance of the first capacitor 1413b and the second capacitor 1414b does not exceed 10pF. The capacitance of the first capacitor 1413b and the second capacitor 1414b can be between 0.01pF and 10pF. The capacitance of the first capacitor 1413b can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the second capacitor 1414b can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0147] The first resonator 1410 has a first inductor 1415b, which provides a zero point for the first filter 1400. The inductance value of the first inductor 1415b does not exceed 10nH, and can be between 0.01nH and 10nH. The inductance value of the first inductor 1415b can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0148] Please refer to Figure 6. The first resonator 1410 includes a first terminal 1411c, a second terminal 1412c, a first capacitor 1413c, a second capacitor 1414c, a first inductor 1415c, and a second inductor 1416c. The first terminals of the first capacitor 1413c and the first inductor 1415c are connected to the first terminal 1411c. The second terminals of the first capacitor 1413c and the first inductor 1415c are connected to the first terminal 1414c. The second terminal of the second capacitor 1414c is connected to the first terminal of the second inductor 1416c. The second terminal of the second inductor 1416c is connected to the second terminal 1412c. One of the first terminal 1411c and the second terminal 1412c is connected to the first port 1100, and the other is connected to the second port 1200. When the first terminal 1411c is connected to the first port 1100, the second terminal 1412c is connected to the second port 1200. When the first endpoint 1411c is connected to the second port 1200, the second endpoint 1412c is connected to the first port 1100.

[0149] The capacitance of the first capacitor 1413c and the second capacitor 1414c does not exceed 10pF, and the capacitance of the first capacitor 1413c and the second capacitor 1414c can be between 0.01pF and 10pF. The capacitance of the first capacitor 1413c can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the second capacitor 1414c can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0150] The first resonator 1410 has a first inductor 1415c and a second inductor 1416c, and the first resonator 1410 is capable of providing two zeros for the first filter 1400. The inductance values ​​of the first inductor 1415c and the second inductor 1416c do not exceed 10nH, and the inductance values ​​of the first inductor 1415c and the second inductor 1416c can be between 0.01nH and 10nH. The inductance value of the first inductor 1415c can be 0.01nH, the inductance value of the first inductor 1415c can be 10nH, and the inductance value of the first inductor 1415c can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the second inductor 1416c can be 0.01nH, the inductance value of the second inductor 1416c can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0151] Please refer to Figure 7. The first resonator 1410 includes a first terminal 1411d, a second terminal 1412d, a first capacitor 1413d, a second capacitor 1414d, a first inductor 1415d, and a second inductor 1416d. The first end of the first inductor 1415d is connected to the first terminal 1411d, and the second end of the first inductor 1415d is connected to the first ends of the first capacitor 1413d and the second inductor 1416d. The second ends of the first capacitor 1413d and the second inductor 1416d are both connected to the first end of the second capacitor 1414d. The second end of the second capacitor 1414d is connected to the second terminal 1412d. One of the first terminal 1411d and the second terminal 1412d is connected to the first port 1100, and the other is connected to the second port 1200. When the first terminal 1411d is connected to the first port 1100, the second terminal 1412d is connected to the second port 1200. When the first endpoint 1411d is connected to the second port 1200, the second endpoint 1412d is connected to the first port 1100.

[0152] The capacitance of the first capacitor 1413d and the second capacitor 1414d does not exceed 10pF, and the capacitance of the first capacitor 1413d and the second capacitor 1414d can be between 0.01pF and 10pF. The capacitance of the first capacitor 1413d can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the second capacitor 1414d can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0153] The first resonator 1410 has a first inductor 1415d and a second inductor 1416d, and the first resonator 1410 is capable of providing two zeros for the first filter 1400. The inductance values ​​of the first inductor 1415d and the second inductor 1416d do not exceed 10nH, and the inductance values ​​of the first inductor 1415d and the second inductor 1416d can be between 0.01nH and 10nH. The inductance value of the first inductor 1415d can be 0.01nH, the inductance value of the first inductor 1415d can be 10nH, and the inductance value of the first inductor 1415d can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the second inductor 1416d can be 0.01nH, the inductance value of the second inductor 1416d can be 10nH, or the inductance value of the second inductor 1416d can be any value from 0.01nH to 10nH (e.g., 5nH).

[0154] Please refer to Figure 8. The first resonator 1410 includes a first terminal 1411e, a second terminal 1412e, a first capacitor 1413e, a second capacitor 1414e, a first inductor 1415e, and a second inductor 1416e. The first end of the first inductor 1415e is connected to the first terminal 1411e. The second end of the first inductor 1415e is connected to the first ends of the first capacitor 1413e and the first ends of the second inductor 1416e. The second end of the second inductor 1416e is connected to the first end of the second capacitor 1414e. The second ends of the first capacitor 1413e and the second ends of the second capacitor 1414e are both connected to the second terminal 1412e. One of the first terminal 1411e and the second terminal 1412e is connected to the first port 1100, and the other is connected to the second port 1200. When the first terminal 1411e is connected to the first port 1100, the second terminal 1412e is connected to the second port 1200. When the first endpoint 1411e is connected to the second port 1200, the second endpoint 1412e is connected to the first port 1100.

[0155] The capacitance of the first capacitor 1413e and the second capacitor 1414e shall not exceed 10pF, and the capacitance of the first capacitor 1413e and the second capacitor 1414e shall be between 0.01pF and 10pF. The capacitance of the first capacitor 1413e may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the second capacitor 1414e may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0156] The first resonator 1410 has a first inductor 1415e and a second inductor 1416e, and the first resonator 1410 is capable of providing two zeros for the first filter 1400. The inductance values ​​of the first inductor 1415e and the second inductor 1416e do not exceed 10nH, and the inductance values ​​of the first inductor 1415e and the second inductor 1416e can be between 0.01nH and 10nH. The inductance value of the first inductor 1415e can be 0.01nH, the inductance value of the first inductor 1415e can be 10nH, and the inductance value of the first inductor 1415e can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the second inductor 1416e can be 0.01nH, the inductance value of the second inductor 1416e can be 10nH, or the inductance value of the second inductor 1416e can be any value from 0.01nH to 10nH (e.g., 5nH).

[0157] Please refer to Figure 9. The first resonator 1410 includes a first terminal 1411f, a second terminal 1412f, a first capacitor 1413f, a second capacitor 1414f, a first inductor 1415f, a second inductor 1416f, and a third inductor 1417f. The first terminal of the first inductor 1415f is connected to the first terminal 1411f, the second terminal of the first inductor 1415f is connected to the first terminal 1413f and the first terminal of the second inductor 1416f, and the second terminal of the second inductor 1416f is connected to the second capacitor 1417f. The first terminal of capacitor 1414f is connected to the first terminal of capacitor 1417f. The second terminal of capacitor 1414f and the second terminal of capacitor 1413f are connected together to the first terminal of capacitor 1417f. The second terminal of capacitor 1417f is connected to the second terminal 1412f. One of the first terminal 1411f and the second terminal 1412f is connected to the first port 1100, and the other is connected to the second port 1200. When the first terminal 1411f is connected to the first port 1100, the second terminal 1412f is connected to the second port 1200. When the first terminal 1411f is connected to the second port 1200, the second terminal 1412f is connected to the first port 1100.

[0158] The capacitance of the first capacitor 1413F and the second capacitor 1414F does not exceed 10pF, and the capacitance of the first capacitor 1413F and the second capacitor 1414F can be between 0.01pF and 10pF. The capacitance of the first capacitor 1413F can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the second capacitor 1414F can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0159] The first resonator 1410 has a first inductor 1415f, a second inductor 1416f, and a third inductor 1417f, and the first resonator 1410 can provide three zeros for the first filter 1400. The inductance values ​​of the first inductor 1415f, the second inductor 1416f, and the third inductor 1417f do not exceed 10nH, and the inductance values ​​of the first inductor 1415f, the second inductor 1416f, and the third inductor 1417f can be between 0.01nH and 10nH. The inductance value of the first inductor 1415f can be 0.01nH, the inductance value of the first inductor 1415f can be 10nH, and the inductance value of the first inductor 1415f can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the second inductor 1416f can be 0.01nH, the inductance value of the second inductor 1416f can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the third inductor 1417f can be 0.01nH, the inductance value of the third inductor 1417f can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0160] Please refer to Figure 10. The first resonator 1410 includes a first terminal 1411g, a second terminal 1412g, a first capacitor 1413g, a second capacitor 1414g, a first inductor 1415g, a second inductor 1416g, and a third inductor 1417g. The first end of the first inductor 1415g is connected to the first terminal 1411g, and the second end of the first inductor 1415g is connected to the first ends of the first capacitor 1413g and the second inductor 1416g. The second ends of the first capacitor 1413g and the second inductor 1416g are both connected to the first end of the second capacitor 1414g. The second end of the second capacitor 1414g is connected to the first end of the third inductor 1417g, and the second end of the third inductor 1417g is connected to the second terminal 1412g. One of the first terminal 1411g and the second terminal 1412g is connected to the first port 1100, and the other is connected to the second port 1200. When the first endpoint 1411g is connected to the first port 1100, the second endpoint 1412g is connected to the second port 1200. When the first endpoint 1411g is connected to the second port 1200, the second endpoint 1412g is connected to the first port 1100.

[0161] The capacitance of the first capacitor 1413g and the second capacitor 1414g does not exceed 10pF, and the capacitance of the first capacitor 1413g and the second capacitor 1414g can be between 0.01pF and 10pF. The capacitance of the first capacitor 1413g can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the second capacitor 1414g can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0162] The first resonator 1410 has a first inductor 1415g, a second inductor 1416g, and a third inductor 1417g, and the first resonator 1410 can provide three zeros for the first filter 1400. The inductance values ​​of the first inductor 1415g, the second inductor 1416g, and the third inductor 1417g do not exceed 10nH, the inductance values ​​of the first inductor 1415g, the second inductor 1416g, and the third inductor 1417g can be between 0.01nH and 10nH, the inductance value of the first inductor 1415g can be 0.01nH, the inductance value of the first inductor 1415g can be 10nH, and the inductance value of the first inductor 1415g can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the second inductor 1416g can be 0.01nH, the inductance value of the second inductor 1416g can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the third inductor 1417g can be 0.01nH, the inductance value of the third inductor 1417g can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0163] Please refer to Figures 11-17. The second resonator 1510 includes one of the following structures:

[0164] Please refer to Figure 11. The second resonator 1510 includes a third terminal 1511a, a fourth terminal 1512a, a fourth inductor 1515a, a third capacitor 1513a, and a fourth capacitor 1514a. The first terminal of the third capacitor 1513a and the first terminal of the fourth inductor 1515a are connected to the third terminal 1511a. The second terminal of the third capacitor 1513a and the second terminal of the fourth inductor 1515a are connected to the first terminal of the fourth capacitor 1514a. The second terminal of the fourth capacitor 1514a is connected to the fourth terminal 1512a. One of the third terminal 1511a and the fourth terminal 1512a is connected to the first port 1100, and the other is connected to the third port 1300. When the third terminal 1511a is connected to the first port 1100, the fourth terminal 1512a is connected to the third port 1300. When the fourth terminal 1512a is connected to the first port 1100, the third terminal 1511a is connected to the third port 1300.

[0165] The capacitance of the third capacitor 1513a and the fourth capacitor 1514a shall not exceed 10pF, but their capacitances can be between 0.01pF and 10pF. The capacitance of the third capacitor 1513a can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the fourth capacitor 1514a can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0166] The second resonator 1510 has a fourth inductor 1515a, which provides a zero point for the second filter 1500. The inductance value of the fourth inductor 1515a does not exceed 10nH, and can be between 0.01nH and 10nH. The inductance value of the fourth inductor 1515a can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0167] Please refer to Figure 12. The second resonator 1510 includes a third terminal 1511b, a fourth terminal 1512b, a fourth inductor 1515b, a third capacitor 1513b, and a fourth capacitor 1514b. The first ends of the third capacitor 1513b and the fourth inductor 1515b are connected to the third terminal 1511b. The second end of the fourth inductor 1515b is connected to the first end of the fourth capacitor 1514b. The second ends of the third capacitor 1513b and the fourth capacitor 1514b are connected to the fourth terminal 1512b. One of the third terminal 1511b and the fourth terminal 1512b is connected to the first port 1100, and the other is connected to the third port 1300. When the third terminal 1511b is connected to the first port 1100, the fourth terminal 1512b is connected to the third port 1300. When the fourth terminal 1512b is connected to the first port 1100, the third terminal 1511b is connected to the third port 1300.

[0168] The capacitance of the third capacitor 1513b and the fourth capacitor 1514b shall not exceed 10pF, but their capacitances can be between 0.01pF and 10pF. The capacitance of the third capacitor 1513b can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the fourth capacitor 1514b can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0169] The second resonator 1510 has a fourth inductor 1515b, which provides a zero point for the second filter 1500. The inductance value of the fourth inductor 1515b does not exceed 10nH, and can be between 0.01nH and 10nH. The inductance value of the fourth inductor 1515b can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0170] Please refer to Figure 13. The second resonator 1510 includes a third terminal 1511c, a fourth terminal 1512c, a third capacitor 1513c, a fourth capacitor 1514c, a fourth inductor 1515c, and a fifth inductor 1516c. The first terminals of the third capacitor 1513c and the fourth inductor 1515c are connected to the third terminal 1511c. The second terminals of the third capacitor 1513c and the fourth inductor 1515c are connected to the first terminal of the fourth capacitor 1514c. The second terminal of the fourth capacitor 1514c is connected to... The first end of the fifth inductor 1516c is connected, the second end of the fifth inductor 1516c is connected to the fourth end 1512c, one of the third end 1511c and the fourth end 1512c is connected to the first port 1100, and the other is connected to the third port 1300; when the third end 1511c is connected to the first port 1100, the fourth end 1512c is connected to the third port 1300, and when the fourth end 1512c is connected to the first port 1100, the third end 1511c is connected to the third port 1300.

[0171] The capacitance of the third capacitor 1513c and the fourth capacitor 1514c does not exceed 10pF, but their capacitance can be between 0.01pF and 10pF. The capacitance of the third capacitor 1513c can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the fourth capacitor 1514c can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0172] The second resonator 1510 has a fourth inductor 1515c and a fifth inductor 1516c, and the second resonator 1510 can provide two zeros for the second filter 1500. The inductance values ​​of the fourth inductor 1515c and the fifth inductor 1516c are both no more than 10nH, and the inductance values ​​of the fourth inductor 1515c and the fifth inductor 1516c can both be between 0.01nH and 10nH. The inductance value of the fourth inductor 1515c can be 0.01nH, the inductance value of the fourth inductor 1515c can be 10nH, and the inductance value of the fourth inductor 1515c can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the fifth inductor 1516c can be 0.01nH, the inductance value of the fifth inductor 1516c can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0173] Referring to Figure 14, the second resonator 1510 includes a third terminal 1511d, a fourth terminal 1512d, a third capacitor 1513d, a fourth capacitor 1514d, a fourth inductor 1515d, and a fifth inductor 1516d. The first terminal of the fourth inductor 1515d is connected to the third terminal 1511d, and the second terminal of the fourth inductor 1515d is connected to the first terminal of the third capacitor 1513d and the first terminal of the fifth inductor 1516d. The second terminals of the third capacitor 1513d and the fifth inductor 1516d are connected together to the third terminal 1511d. The first terminal of the four capacitors 1514d is connected, the second terminal of the fourth capacitor 1514d is connected to the fourth terminal 1512d, one of the third terminal 1511d and the fourth terminal 1512d is connected to the first port 1100, and the other is connected to the third port 1300; when the third terminal 1511d is connected to the first port 1100, the fourth terminal 1512d is connected to the third port 1300, and when the fourth terminal 1512d is connected to the first port 1100, the third terminal 1511d is connected to the third port 1300.

[0174] The capacitances of the third capacitor 1513d and the fourth capacitor 1514d do not exceed 10pF, but their capacitances can range from 0.01pF to 10pF. The capacitance of the third capacitor 1513d can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the fourth capacitor 1514d can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0175] The second resonator 1510 has a fourth inductor 1515d and a fifth inductor 1516d, and the second resonator 1510 can provide two zeros for the second filter 1500. The inductance values ​​of the fourth inductor 1515d and the fifth inductor 1516d are both no more than 10nH. The inductance values ​​of the fourth inductor 1515d and the fifth inductor 1516d can both be between 0.01nH and 10nH. The inductance value of the fourth inductor 1515d can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the fifth inductor 1516d can be 0.01nH, the inductance value of the fifth inductor 1516d can be 10nH, or the inductance value of the fifth inductor 1516d can be any value from 0.01nH to 10nH (e.g., 5nH).

[0176] Please refer to Figure 15. The second resonator 1510 includes a third terminal 1511e, a fourth terminal 1512e, a third capacitor 1513e, a fourth capacitor 1514e, a fourth inductor 1515e, and a fifth inductor 1516e. The first terminal of the fourth inductor 1515e is connected to the third terminal 1511e. The second terminal of the fourth inductor 1515e is connected to the first terminals of the third capacitor 1513e and the fifth inductor 1516e. The second terminal of the fifth inductor 1516e is connected to the first terminal of the fourth capacitor 1514e. The second terminals of the three capacitors 1513e and 1514e are both connected to the fourth terminal 1512e. One of the third terminal 1511e and the fourth terminal 1512e is connected to the first port 1100, and the other is connected to the third port 1300. When the third terminal 1511e is connected to the first port 1100, the fourth terminal 1512e is connected to the third port 1300; conversely, when the fourth terminal 1512e is connected to the first port 1100, the third terminal 1511e is connected to the third port 1300. The capacitance of both the third capacitor 1513e and the fourth capacitor 1514e does not exceed 10pF, and their capacitance can be between 0.01pF and 10pF. The capacitance of the third capacitor 1513e can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the fourth capacitor 1514e can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0177] The second resonator 1510 has a fourth inductor 1515e and a fifth inductor 1516e, and the second resonator 1510 can provide two zeros for the second filter 1500. The inductance values ​​of the fourth inductor 1515e and the fifth inductor 1516e are both no more than 10nH, and the inductance values ​​of the fourth inductor 1515e and the fifth inductor 1516e can both be between 0.01nH and 10nH. The inductance value of the fourth inductor 1515e can be 0.01nH, the inductance value of the fourth inductor 1515e can be 10nH, and the inductance value of the fourth inductor 1515e can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the fifth inductor 1516e can be 0.01nH, the inductance value of the fifth inductor 1516e can be 10nH, or the inductance value of the fifth inductor 1516e can be any value from 0.01nH to 10nH (e.g., 5nH).

[0178] Referring to Figure 16, the second resonator 1510 includes a third terminal 1511f, a fourth terminal 1512f, a third capacitor 1513f, a fourth capacitor 1514f, a fourth inductor 1515f, a fifth inductor 1516f, and a sixth inductor 1517f. The first terminal of the fourth inductor 1515f is connected to the third terminal 1511f, the second terminal of the fourth inductor 1515f is connected to the first terminals of the third capacitor 1513f and the fifth inductor 1516f, the second terminal of the fifth inductor 1516f is connected to the first terminal of the fourth capacitor 1514f, and the fourth capacitor 1517f... The second terminal of the second capacitor 1513f and the second terminal of the third capacitor 1513f are connected together to the first terminal of the sixth inductor 1517f. The second terminal of the sixth inductor 1517f is connected to the fourth terminal 1512f. One of the third terminal 1511f and the fourth terminal 1512f is connected to the first port 1100, and the other is connected to the third port 1300. When the third terminal 1511f is connected to the first port 1100, the fourth terminal 1512f is connected to the third port 1300. When the fourth terminal 1512f is connected to the first port 1100, the third terminal 1511f is connected to the third port 1300.

[0179] The capacitance of the third capacitor 1513F and the fourth capacitor 1514F shall not exceed 10pF, and their capacitances may range from 0.01pF to 10pF. The capacitance of the third capacitor 1513F may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the fourth capacitor 1514F may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0180] The second resonator 1510 has a fourth inductor 1515f, a fifth inductor 1516f, and a sixth inductor 1517f, and the second resonator 1510 can provide three zeros for the second filter 1500. The inductance values ​​of the fourth inductor 1515f, the fifth inductor 1516f, and the sixth inductor 1517f are all no more than 10nH. The inductance values ​​of the fourth inductor 1515f, the fifth inductor 1516f, and the sixth inductor 1517f can all be between 0.01nH and 10nH. The inductance value of the fourth inductor 1515f can be 0.01nH, the inductance value of the fourth inductor 1515f can be 10nH, and the inductance value of the fourth inductor 1515f can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the fifth inductor 1516f can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the sixth inductor 1517f can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0181] Please refer to Figure 17. The second resonator 1510 includes a third terminal 1511g, a fourth terminal 1512g, a third capacitor 1513g, a fourth capacitor 1514g, a fourth inductor 1515g, a fifth inductor 1516g, and a sixth inductor 1517g. The first end of the fourth inductor 1515g is connected to the third terminal 1511g, the second end of the fourth inductor 1515g is connected to the first ends of the third capacitor 1513g and the fifth inductor 1516g, the second ends of the third capacitor 1513g and the fifth inductor 1516g are jointly connected to the first end of the fourth capacitor 1514g, the second end of the fourth capacitor 1514g is connected to the first end of the sixth inductor 1517g, the second end of the sixth inductor 1517g is connected to the fourth terminal 1512g, one of the third terminal 1511g and the fourth terminal 1512g is connected to the first port 1100, and the other is connected to the third port 1300. When the third endpoint 1511g is connected to the first port 1100, the fourth endpoint 1512g is connected to the third port 1300. When the fourth endpoint 1512g is connected to the first port 1100, the third endpoint 1511g is connected to the third port 1300.

[0182] The capacitance of the third capacitor 1513g and the fourth capacitor 1514g shall not exceed 10pF, but their capacitance can be between 0.01pF and 10pF. The capacitance of the third capacitor 1513g can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the fourth capacitor 1514g can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0183] The second resonator 1510 has a fourth inductor 1515g, a fifth inductor 1516g, and a sixth inductor 1517g, which provides three zeros for the second filter 1500. The inductance values ​​of the fourth inductor 1515g, the fifth inductor 1516g, and the sixth inductor 1517g all do not exceed 10nH. The inductance values ​​of the fourth inductor 1515g, the fifth inductor 1516g, and the sixth inductor 1517g can all be between 0.01nH and 10nH. The inductance value of the fourth inductor 1515g can be 0.01nH, the inductance value of the fourth inductor 1515g can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the fifth inductor 1516g can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the sixth inductor 1517g can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0184] In the embodiments provided in this application, please refer to FIG18. The first resonator 1410 includes a first terminal, a second terminal, a first inductor, a first capacitor, and a second capacitor. The first terminal of the first capacitor and the first terminal of the first inductor are connected to the first terminal. The second terminal of the first capacitor and the second terminal of the first inductor are connected to the first terminal of the second capacitor. The second terminal of the second capacitor is connected to the second terminal. One of the first terminal and the second terminal is connected to the first port 1100, and the other is connected to the second port 1200. The second resonator 1510 includes a third terminal, a fourth terminal, a fourth inductor, a third capacitor, and a fourth capacitor. The first terminal of the third capacitor and the first terminal of the fourth inductor are connected to the third terminal. The second terminal of the third capacitor and the second terminal of the fourth inductor are connected to the first terminal of the fourth capacitor. The second terminal of the fourth capacitor is connected to the fourth terminal. One of the third terminal and the fourth terminal is connected to the first port 1100, and the other is connected to the third port 1300.

[0185] The first resonator 1410 is connected in series between the first port 1100 and the second port 1200, and the second resonator 1510 is connected in series between the first port 1100 and the third port 1300. The first resonator 1410 and the second resonator 1510 have the same topology, which is beneficial for the first resonator 1410 and the second resonator 1510 to achieve admittance matching (e.g., admittance complementarity).

[0186] In the multiplexer 1000 provided in this application, even if the passbands of the first filter 1400 and the second filter 1500 are close together, the first resonator 1410 and the second resonator 1510 with the same topology in the multiplexer 1000 can still prevent crosstalk when the multiplexer 1000 transmits radio frequency signals in two different frequency bands. For example, the passband of the first filter 1400 can be the N77 band, with a frequency range of 3.3 GHz to 4.2 GHz, and the passband of the second filter 1500 can be the N79 band, with a frequency range of 4.4 GHz to 5.0 GHz. When the multiplexer 1000 transmits radio frequency signals in both the N77 and N79 bands simultaneously, there is no need to set up a frequency divider or additional matching circuit in the multiplexer 1000 to prevent crosstalk during radio frequency signal transmission. This is beneficial for the miniaturization of the multiplexer 1000 and for reducing insertion loss. If a frequency divider or additional matching circuit is added to the multiplexer 1000, the frequency divider or additional matching circuit will inevitably consume the energy of the multiplexer 1000 during radio frequency signal transmission, resulting in excessive insertion loss.

[0187] In the embodiments provided in this application, the first resonator 1410 is composed of three reactive components (such as a first capacitor, a second capacitor, and a first inductor), and can provide a zero point for the first filter 1400, enabling the first filter 1400 to achieve filtering function in a specific frequency band. Furthermore, the number of reactive components constituting the first resonator 1410 is small, the topology of the first resonator 1410 is simple, it also facilitates the miniaturization of the multiplexer 1000, and can reduce the insertion loss of the multiplexer 1000. Similarly, the second resonator 1510 is composed of three reactive components (such as a first capacitor, a second capacitor, and a first inductor), and can provide a zero point for the second filter 1500, enabling the second filter 1500 to achieve filtering function in a specific frequency band. Furthermore, the number of reactive components constituting the second resonator 1510 is small, the topology of the second resonator 1510 is simple, it also facilitates the miniaturization of the multiplexer 1000, and can reduce the insertion loss of the multiplexer 1000.

[0188] In some embodiments, the first filter 1400 further includes a third resonator 1420, the input terminal of the third resonator 1420 being connected to the output terminal of the first resonator 1410, the output terminal of the first resonator 1410 being connected to the first port 1100, and the output terminal of the third resonator 1420 being grounded.

[0189] In some embodiments, the first filter 1400 further includes a third resonator 1420, the input terminal of the third resonator 1420 being connected to the output terminal of the first resonator 1410, and the output terminal of the third resonator 1420 being connected to the second port 1200.

[0190] In some embodiments, the first filter 1400 further includes a third resonator 1420 and a fourth resonator 1430, the fourth resonator 1430 being connected in series between the first resonator 1410 and the second port 1200, the input terminal of the third resonator 1420 being connected between the first resonator 1410 and the fourth resonator 1430, and the output terminal of the third resonator 1420 being grounded.

[0191] In the embodiments provided in this application, the first filter 1400 can be a third-order filter. A third-order filter has fewer reactive components, which helps reduce the insertion loss of the multiplexer 1000. The third-order first filter 1400 can provide three zeros. The third resonator 1420 can provide one zero for the first filter 1400, and the input terminal of the third resonator 1420 is connected between the first resonator 1410 and the fourth resonator 1430. The output terminal of the third resonator 1420 is grounded. When transmitting radio frequency signals, since the third resonator 1420 is not connected in series with the first port 1100 and the second port 1200, the insertion loss of the first filter 1400 during radio frequency signal transmission is reduced.

[0192] In some embodiments, referring to FIG19, the first filter 1400 further includes a third resonator 1420 and a fourth resonator 1430. The input terminal of the third resonator 1420 is connected to the output terminal of the first resonator 1410, the output terminal of the third resonator 1420 is connected to the input terminal of the fourth resonator 1430, and the output terminal of the fourth resonator 1430 is connected to the second port 1200. The first filter 1400 can be a third-order filter. A third-order filter has fewer reactive components, which helps to reduce the insertion loss of the multiplexer 1000.

[0193] In some embodiments, referring to FIG20, the first filter 1400 further includes a third resonator 1420 and a fourth resonator 1430. The input terminal of the third resonator 1420 is connected to the output terminal of the first resonator 1410, and the output terminal of the third resonator 1420 and the input terminal of the fourth resonator 1430 are both connected to the second port 1200. The output terminal of the fourth resonator 1430 is grounded. The first filter 1400 can be a third-order filter. A third-order filter has fewer reactive components, which helps to reduce the insertion loss of the multiplexer 1000. The third-order first filter 1400 can provide three zeros. The fourth resonator 1430 can provide one zero for the first filter 1400, and the input terminal of the fourth resonator 1430 is connected to the output terminal of the third resonator 1420. The output terminal of the fourth resonator 1430 is grounded. When the first filter 1400 transmits radio frequency signals, since the fourth resonator 1430 is not connected in series with the first port 1100 and the second port 1200, it helps to reduce the insertion loss of the first filter 1400 when transmitting radio frequency signals.

[0194] Please refer to Figures 21-27. The third resonator 1420 includes one of the following structures:

[0195] In some embodiments, referring to FIG21, the third resonator 1420 includes a fifth terminal 1421a, a sixth terminal 1422a, a seventh inductor 1425a, a fifth capacitor 1423a, and a sixth capacitor 1424a. The first terminal of the fifth capacitor 1423a and the first terminal of the seventh inductor 1425a are connected to the fifth terminal 1421a. The second terminal of the fifth capacitor 1423a and the second terminal of the seventh inductor 1425a are connected to the first terminal of the sixth capacitor 1424a. The second terminal of the sixth capacitor 1424a is connected to the sixth terminal 1422a. One of the fifth terminal 1421a and the sixth terminal 1422a is the input terminal of the third resonator 1420, and the other is the output terminal of the third resonator 1420.

[0196] The capacitance of the fifth capacitor 1423a and the sixth capacitor 1424a shall not exceed 10pF. The capacitance of the fifth capacitor 1423a and the sixth capacitor 1424a may be between 0.01pF and 10pF. The capacitance of the fifth capacitor 1423a may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the sixth capacitor 1424a may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0197] The third resonator 1420 has a seventh inductor 1425a, which provides a zero point for the first filter 1400. The inductance value of the seventh inductor 1425a does not exceed 10nH, and can be between 0.01nH and 10nH. The inductance value of the seventh inductor 1425a can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0198] In one feasible implementation, the third resonator 1420 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the fifth terminal 1421a and the sixth terminal 1422a is connected to the output terminal of the first resonator 1410, and the other is connected to the second port 1200. In some embodiments, one of the fifth terminal 1421a and the sixth terminal 1422a is connected to the output terminal of the first resonator 1410, and the other is grounded.

[0199] In some embodiments, referring to FIG22, the third resonator 1420 includes a fifth terminal 1421b, a sixth terminal 1422b, a seventh inductor 1425b, a fifth capacitor 1423b, and a sixth capacitor 1424b. The first terminal of the fifth capacitor 1423b and the first terminal of the seventh inductor 1425b are connected to the third terminal. The second terminal of the seventh inductor 1425b is connected to the first terminal of the sixth capacitor 1424b. The second terminal of the fifth capacitor 1423b and the second terminal of the sixth capacitor 1424b are connected to the sixth terminal 1422b. One of the fifth terminal 1421b and the sixth terminal 1422b is the input terminal of the third resonator 1420, and the other is the output terminal of the third resonator 1420.

[0200] The capacitance of the fifth capacitor 1423b and the sixth capacitor 1424b shall not exceed 10pF. The capacitance of the fifth capacitor 1423b and the sixth capacitor 1424b may be between 0.01pF and 10pF. The capacitance of the fifth capacitor 1423b may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the sixth capacitor 1424b may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0201] The third resonator 1420 has a seventh inductor 1425b, which provides a zero point for the first filter 1400. The inductance value of the seventh inductor 1425b does not exceed 10nH, and can be between 0.01nH and 10nH. The inductance value of the seventh inductor 1425b can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0202] In one feasible implementation, the third resonator 1420 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the fifth terminal 1421b and the sixth terminal 1422b is connected to the output of the first resonator 1410, and the other is connected to the second port 1200. In some embodiments, one of the fifth terminal 1421b and the sixth terminal 1422b is connected to the output of the first resonator 1410, and the other is grounded.

[0203] In some embodiments, referring to FIG23, the third resonator 1420 includes a fifth terminal 1421c, a sixth terminal 1422c, a fifth capacitor 1423c, a sixth capacitor 1424c, a seventh inductor 1425c, and an eighth inductor 1426c; the first terminals of the fifth capacitor 1423c and the seventh inductor 1425c are connected to the fifth terminal 1421c, the second terminals of the fifth capacitor 1423c and the seventh inductor 1425c are connected to the first terminal of the sixth capacitor 1424c, the second terminal of the sixth capacitor is connected to the first terminal of the eighth inductor 1426c, and the second terminal of the eighth inductor 1426c is connected to the sixth terminal 1422c; one of the fifth terminal 1421c and the sixth terminal 1422c is the input terminal of the third resonator 1420, and the other is the output terminal of the third resonator 1420.

[0204] The capacitance of the fifth capacitor 1423c and the sixth capacitor 1424c does not exceed 10pF. The capacitance of the fifth capacitor 1423c and the sixth capacitor 1424c can be between 0.01pF and 10pF. The capacitance of the fifth capacitor 1423c can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the sixth capacitor 1424c can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0205] The third resonator 1420 has a seventh inductor 1425c and an eighth inductor 1426c, and the third resonator 1420 can provide two zeros for the first filter 1400. The inductance values ​​of the seventh inductor 1425c and the eighth inductor 1426c do not exceed 10nH, and the inductance values ​​of the seventh inductor 1425c can be between 0.01nH and 10nH. The inductance value of the seventh inductor 1425c can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the eighth inductor 1426c can be 0.01nH, the inductance value of the eighth inductor 1426c can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0206] In one feasible implementation, the third resonator 1420 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the fifth terminal 1421c and the sixth terminal 1422c is connected to the output terminal of the first resonator 1410, and the other is connected to the second port 1200. In some embodiments, one of the fifth terminal 1421c and the sixth terminal 1422c is connected to the output terminal of the first resonator 1410, and the other is grounded.

[0207] In some embodiments, referring to FIG24, the third resonator 1420 includes a fifth terminal 1421d, a sixth terminal 1422d, a fifth capacitor 1423d, a sixth capacitor 1424d, a seventh inductor 1425d, and an eighth inductor 1426d; the first terminal of the seventh inductor 1425d is connected to the fifth terminal 1421d, the second terminal of the seventh inductor 1425d is connected to the first terminals of the fifth capacitor 1423d and the eighth inductor 1426d, the second terminals of the fifth capacitor 1423d and the eighth inductor 1426d are jointly connected to the first terminal of the sixth capacitor 1424d, and the second terminal of the sixth capacitor 1424d is connected to the sixth terminal 1422d; one of the fifth terminal 1421d and the sixth terminal 1422d is the input terminal of the third resonator 1420, and the other is the output terminal of the third resonator 1420.

[0208] The capacitance of the fifth capacitor 1423d and the sixth capacitor 1424d shall not exceed 10pF. The capacitance of the fifth capacitor 1423d and the sixth capacitor 1424d may be between 0.01pF and 10pF. The capacitance of the fifth capacitor 1423d may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the sixth capacitor 1424d may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0209] The third resonator 1420 has a seventh inductor 1425d and an eighth inductor 1426d, and the third resonator 1420 can provide two zeros for the first filter 1400. The inductance values ​​of the seventh inductor 1425d and the eighth inductor 1426d do not exceed 10nH, and the inductance values ​​of the seventh inductor 1425d and the eighth inductor 1426d can be between 0.01nH and 10nH. The inductance value of the seventh inductor 1425d can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the eighth inductor 1426d can be 0.01nH, the inductance value of the eighth inductor 1426d can be 10nH, or the inductance value of the eighth inductor 1426d can be any value from 0.01nH to 10nH (e.g., 5nH).

[0210] In one feasible implementation, the third resonator 1420 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the fifth terminal 1421d and the sixth terminal 1422d is connected to the output of the first resonator 1410, and the other is connected to the second port 1200. In some embodiments, one of the fifth terminal 1421d and the sixth terminal 1422d is connected to the output of the first resonator 1410, and the other is grounded.

[0211] In some embodiments, referring to FIG25, the third resonator 1420 includes a fifth terminal 1421e, a sixth terminal 1422e, a fifth capacitor 1423e, a sixth capacitor 1424e, a seventh inductor 1425e, and an eighth inductor 1426e. The first terminal of the seventh inductor 1425e is connected to the fifth terminal 1421e, the second terminal of the seventh inductor 1425e is connected to the first terminals of the fifth capacitor 1423e and the eighth inductor 1426e, the second terminal of the eighth inductor 1426e is connected to the first terminal of the sixth capacitor 1424e, and the second terminals of the fifth capacitor 1423e and the sixth capacitor 1424e are jointly connected to the sixth terminal 1422e. One of the fifth terminal 1421e and the sixth terminal 1422e is the input terminal of the third resonator 1420, and the other is the output terminal of the third resonator 1420.

[0212] The capacitance of the fifth capacitor 1423e and the sixth capacitor 1424e shall not exceed 10pF. The capacitance of the fifth capacitor 1423e and the sixth capacitor 1424e may be between 0.01pF and 10pF. The capacitance of the fifth capacitor 1423e may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the sixth capacitor 1424e may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0213] The third resonator 1420 has a seventh inductor 1425e and an eighth inductor 1426e, and the third resonator 1420 can provide two zeros for the first filter 1400. The inductance values ​​of the seventh inductor 1425e and the eighth inductor 1426e do not exceed 10nH, and the inductance values ​​of the seventh inductor 1425e and the eighth inductor 1426e can be between 0.01nH and 10nH. The inductance value of the seventh inductor 1425e can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the eighth inductor 1426e can be 0.01nH, the inductance value of the eighth inductor 1426e can be 10nH, or the inductance value of the eighth inductor 1426e can be any value from 0.01nH to 10nH (e.g., 5nH).

[0214] In one feasible implementation, the third resonator 1420 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the fifth terminal 1421e and the sixth terminal 1422e is connected to the output of the first resonator 1410, and the other is connected to the second port 1200. In some embodiments, one of the fifth terminal 1421e and the sixth terminal 1422e is connected to the output of the first resonator 1410, and the other is grounded.

[0215] In some embodiments, referring to FIG26, the third resonator 1420 includes a fifth terminal 1421f, a sixth terminal 1422f, a fifth capacitor 1423f, a sixth capacitor 1424f, a seventh inductor 1425f, an eighth inductor 1426f, and a ninth inductor 1427f; the first terminal of the seventh inductor 1425f is connected to the fifth terminal 1421f, the second terminal of the seventh inductor 1425f is connected to the first terminals of the fifth capacitor 1423f and the eighth inductor 1426f, the second terminal of the eighth inductor 1426f is connected to the first terminal of the sixth capacitor 1424f, the second terminal of the sixth capacitor 1424f and the second terminal of the fifth capacitor 1423f are jointly connected to the first terminal of the ninth inductor 1427f, and the second terminal of the ninth inductor 1427f is connected to the sixth terminal 1422f.

[0216] The capacitance of the fifth capacitor 1423F and the sixth capacitor 1424F shall not exceed 10pF. The capacitance of the fifth capacitor 1423F and the sixth capacitor 1424F can be between 0.01pF and 10pF. The capacitance of the fifth capacitor 1423F can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the sixth capacitor 1424F can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0217] The third resonator 1420 has a seventh inductor 1425f, an eighth inductor 1426f, and a ninth inductor 1427f, which provides three zeros for the first filter 1400. The inductance values ​​of the seventh inductor 1425f, the eighth inductor 1426f, and the ninth inductor 1427f are all no more than 10nH, and their values ​​can be between 0.01nH and 10nH. The inductance value of the seventh inductor 1425f can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the eighth inductor 1426f can be 0.01nH, the inductance value of the eighth inductor 1426f can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the ninth inductor 1427f can be 0.01nH, the inductance value of the ninth inductor 1427f can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0218] In one feasible implementation, the third resonator 1420 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the fifth terminal 1421f and the sixth terminal 1422f is connected to the output terminal of the first resonator 1410, and the other is connected to the second port 1200. In some embodiments, one of the fifth terminal 1421f and the sixth terminal 1422f is connected to the output terminal of the first resonator 1410, and the other is grounded.

[0219] In some embodiments, as shown in FIG27, the third resonator 1420 includes a fifth terminal 1421g, a sixth terminal 1422g, a fifth capacitor 1423g, a sixth capacitor 1424g, a seventh inductor 1425g, an eighth inductor 1426g, and a ninth inductor 1427g; the first terminal of the seventh inductor 1425g is connected to the fifth terminal 1421g, the second terminal of the seventh inductor 1425g is connected to the first terminals of the fifth capacitor 1423g and the eighth inductor 1426g, the second terminals of the fifth capacitor 1423g and the eighth inductor 1426g are jointly connected to the first terminal of the sixth capacitor 1424g, the second terminal of the sixth capacitor 1424g is connected to the first terminal of the ninth inductor 1427g, and the second terminal of the ninth inductor 1427g is connected to the sixth terminal 1422g; one of the fifth terminal 1421g and the sixth terminal 1422g is the input terminal of the third resonator 1420, and the other is the output terminal of the third resonator 1420.

[0220] The capacitance of the fifth capacitor 1423g and the sixth capacitor 1424g shall not exceed 10pF. The capacitance of the fifth capacitor 1423g and the sixth capacitor 1424g can be between 0.01pF and 10pF. The capacitance of the fifth capacitor 1423g can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the sixth capacitor 1424g can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0221] The third resonator 1420 has a seventh inductor 1425g, an eighth inductor 1426g, and a ninth inductor 1427g, which provides three zeros for the first filter 1400. The inductance values ​​of the seventh inductor 1425g, the eighth inductor 1426g, and the ninth inductor 1427g all do not exceed 10nH, and their values ​​can be between 0.01nH and 10nH. The inductance value of the seventh inductor 1425g can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the eighth inductor 1426g can be 0.01nH, the inductance value of the eighth inductor 1426g can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the ninth inductor 1427g can be 0.01nH, the inductance value of the ninth inductor 1427g can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0222] In one feasible implementation, the third resonator 1420 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the fifth terminal 1421g and the sixth terminal 1422g is connected to the output terminal of the first resonator 1410, and the other is connected to the second port 1200. In some embodiments, one of the fifth terminal 1421g and the sixth terminal 1422g is connected to the output terminal of the first resonator 1410, and the other is grounded.

[0223] Please refer to Figures 28-34. The fourth resonator 1430 includes one of the following structures:

[0224] In some embodiments, referring to FIG28, the fourth resonator 1430 includes a seventh terminal 1431a, an eighth terminal 1432a, a tenth inductor 1435a, a seventh capacitor 1433a, and an eighth capacitor 1434a. The first terminal of the seventh capacitor 1433a and the first terminal of the tenth inductor 1435a are connected to the seventh terminal 1431a. The second terminal of the seventh capacitor 1433a and the second terminal of the tenth inductor 1435a are connected to the first terminal of the eighth capacitor 1434a. The second terminal of the eighth capacitor 1434a is connected to the eighth terminal 1432a. One of the seventh terminal 1431a and the eighth terminal 1432a is the input terminal of the fourth resonator 1430, and the other is the output terminal of the fourth resonator 1430.

[0225] The capacitance of the seventh capacitor 1433a and the eighth capacitor 1434a does not exceed 10pF, but their capacitance can be between 0.01pF and 10pF. The capacitance of the seventh capacitor 1433a can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the eighth capacitor 1434a can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0226] The fourth resonator 1430 has a tenth inductor 1435a, which provides a zero point for the first filter 1400. The inductance value of the tenth inductor 1435a does not exceed 10nH, and can be between 0.01nH and 10nH. The inductance value of the tenth inductor 1435a can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0227] In one feasible implementation, the fourth resonator 1430 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the seventh terminal 1431a and the eighth terminal 1432a is connected to the output terminal of the first resonator 1410 or the output terminal of the third resonator 1420, and the other is connected to the second port 1200. In some embodiments, the fourth resonator 1430 can be connected in parallel with the first resonator 1410. For example, one of the seventh terminal 1431a and the eighth terminal 1432a is connected to the second port 1200, and the other is grounded.

[0228] In some embodiments, referring to FIG29, the fourth resonator 1430 includes a seventh terminal 1431b, an eighth terminal 1432b, a tenth inductor 1435b, a seventh capacitor 1433b, and an eighth capacitor 1434b. The first terminal of the seventh capacitor 1433b and the first terminal of the tenth inductor 1435b are connected to the seventh terminal 1431b. The second terminal of the tenth inductor 1435b is connected to the first terminal of the eighth capacitor 1434b. The second terminals of the seventh capacitor 1433b and the second terminals of the eighth capacitor 1434b are connected to the eighth terminal 1432b. One of the seventh terminal 1431b and the eighth terminal 1432b is the input terminal of the fourth resonator 1430, and the other is the output terminal of the fourth resonator 1430.

[0229] The capacitance of the seventh capacitor 1433b and the eighth capacitor 1434b does not exceed 10pF, but their capacitance can be between 0.01pF and 10pF. The capacitance of the seventh capacitor 1433b can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the eighth capacitor 1434b can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0230] The fourth resonator 1430 has a tenth inductor 1435b, which provides a zero point for the first filter 1400. The inductance value of the tenth inductor 1435b does not exceed 10nH, and can be between 0.01nH and 10nH. The inductance value of the tenth inductor 1435b can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0231] In one feasible implementation, the fourth resonator 1430 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the seventh terminal 1431b and the eighth terminal 1432b is connected to the output terminal of the first resonator 1410 or the output terminal of the third resonator 1420, and the other is connected to the second port 1200. In some embodiments, the fourth resonator 1430 can be connected in parallel with the first resonator 1410. For example, one of the seventh terminal 1431b and the eighth terminal 1432b is connected to the second port 1200, and the other is grounded.

[0232] In some embodiments, referring to FIG30, the fourth resonator 1430 includes a seventh terminal 1431c, an eighth terminal 1432c, a seventh capacitor 1433c, an eighth capacitor 1434c, a tenth inductor 1435c, and an eleventh inductor 1436c; the first terminals of the seventh capacitor 1433c and the tenth inductor 1435c are connected to the seventh terminal 1431c, the second terminals of the seventh capacitor 1433c and the tenth inductor 1435c are connected to the first terminal of the eighth capacitor 1434c, the second terminal of the eighth capacitor is connected to the first terminal of the eleventh inductor 1436c, and the second terminal of the eleventh inductor 1436c is connected to the eighth terminal 1432c; one of the seventh terminal 1431c and the eighth terminal 1432c is the input terminal of the fourth resonator 1430, and the other is the output terminal of the fourth resonator 1430.

[0233] The capacitance of the seventh capacitor 1433c and the eighth capacitor 1434c does not exceed 10pF. The capacitance of the seventh capacitor 1433c can be between 0.01pF and 10pF. The capacitance of the seventh capacitor 1433c can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the eighth capacitor 1434c can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0234] The fourth resonator 1430 has a tenth inductor 1435c and an eleventh inductor 1436c, which can provide two zeros for the first filter 1400. The inductance values ​​of the tenth inductor 1435c and the eleventh inductor 1436c do not exceed 10nH, and the inductance values ​​of the tenth inductor 1435c and the eleventh inductor 1436c can be between 0.01nH and 10nH. The inductance value of the tenth inductor 1435c can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the eleventh inductor 1436c can be 0.01nH, the inductance value of the eleventh inductor 1436c can be 10nH, and the inductance value of the eleventh inductor 1436c can be any value from 0.01nH to 10nH (e.g., 5nH).

[0235] In one feasible implementation, the fourth resonator 1430 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the seventh terminal 1431c and the eighth terminal 1432c is connected to the output terminal of the first resonator 1410 or the output terminal of the third resonator 1420, and the other is connected to the second port 1200. In some embodiments, the fourth resonator 1430 can be connected in parallel with the first resonator 1410. For example, one of the seventh terminal 1431c and the eighth terminal 1432c is connected to the second port 1200, and the other is grounded.

[0236] In some embodiments, referring to FIG31, the fourth resonator 1430 includes a seventh terminal 1431d, an eighth terminal 1432d, a seventh capacitor 1433d, an eighth capacitor 1434d, a tenth inductor 1435d, and an eleventh inductor 1436d; the first end of the tenth inductor 1435d is connected to the seventh terminal 1431d, the second end of the tenth inductor 1435d is connected to the first ends of the seventh capacitor 1433d and the eleventh inductor 1436d, the second ends of the seventh capacitor 1433d and the eleventh inductor 1436d are jointly connected to the first end of the eighth capacitor 1434d, and the second end of the eighth capacitor 1434d is connected to the eighth terminal 1432d; one of the seventh terminal 1431d and the eighth terminal 1432d is the input terminal of the fourth resonator 1430, and the other is the output terminal of the fourth resonator 1430.

[0237] The capacitance of the seventh capacitor 1433d and the eighth capacitor 1434d does not exceed 10pF, but their capacitance can be between 0.01pF and 10pF. The capacitance of the seventh capacitor 1433d can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the eighth capacitor 1434d can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0238] The fourth resonator 1430 has a tenth inductor 1435d and an eleventh inductor 1436d, which can provide two zeros for the first filter 1400. The inductance values ​​of the tenth inductor 1435d and the eleventh inductor 1436d do not exceed 10nH, and the inductance values ​​of the tenth inductor 1435d and the eleventh inductor 1436d can be between 0.01nH and 10nH. The inductance value of the tenth inductor 1435d can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the eleventh inductor 1436d can be 0.01nH, the inductance value of the eleventh inductor 1436d can be 10nH, and the inductance value of the eleventh inductor 1436d can be any value from 0.01nH to 10nH (e.g., 5nH).

[0239] In one feasible implementation, the fourth resonator 1430 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the seventh terminal 1431d and the eighth terminal 1432d is connected to the output terminal of the first resonator 1410 or the output terminal of the third resonator 1420, and the other is connected to the second port 1200. In some embodiments, the fourth resonator 1430 can be connected in parallel with the first resonator 1410. For example, one of the seventh terminal 1431d and the eighth terminal 1432d is connected to the second port 1200, and the other is grounded.

[0240] In some embodiments, referring to FIG32, the fourth resonator 1430 includes a seventh terminal 1431e, an eighth terminal 1432e, a seventh capacitor 1433e, an eighth capacitor 1434e, a tenth inductor 1435e, and an eleventh inductor 1436e; the first end of the tenth inductor 1435e is connected to the seventh terminal 1431e, the second end of the tenth inductor 1435e is connected to the first end of the seventh capacitor 1433e and the first end of the eleventh inductor 1436e, the second end of the eleventh inductor 1436e is connected to the first end of the eighth capacitor 1434e, and the second ends of the seventh capacitor 1433e and the eighth capacitor 1434e are jointly connected to the eighth terminal 1432e; one of the seventh terminal 1431e and the eighth terminal 1432e is the input terminal of the fourth resonator 1430, and the other is the output terminal of the fourth resonator 1430.

[0241] The capacitance of the seventh capacitor 1433e and the eighth capacitor 1434e both do not exceed 10pF, but their capacitances can range from 0.01pF to 10pF. The capacitance of the seventh capacitor 1433e can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the eighth capacitor 1434e can be either 0.01pF or 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0242] The fourth resonator 1430 has a tenth inductor 1435e and an eleventh inductor 1436e, and the fourth resonator 1430 can provide two zeros for the first filter 1400. The inductance values ​​of the tenth inductor 1435e and the eleventh inductor 1436e do not exceed 10nH, and the inductance values ​​of the tenth inductor 1435e and the eleventh inductor 1436e can be between 0.01nH and 10nH. The inductance value of the tenth inductor 1435e can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the eleventh inductor 1436e can be 0.01nH, the inductance value of the eleventh inductor 1436e can be 10nH, and the inductance value of the eleventh inductor 1436e can be any value from 0.01nH to 10nH (e.g., 5nH).

[0243] In one feasible implementation, the fourth resonator 1430 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the seventh terminal 1431e and the eighth terminal 1432e is connected to the output terminal of the first resonator 1410 or the output terminal of the third resonator 1420, and the other is connected to the second port 1200. In some embodiments, the fourth resonator 1430 can be connected in parallel with the first resonator 1410. For example, one of the seventh terminal 1431e and the eighth terminal 1432e is connected to the second port 1200, and the other is grounded.

[0244] In some embodiments, referring to FIG33, the fourth resonator 1430 includes a seventh terminal 1431f, an eighth terminal 1432f, a seventh capacitor 1433f, an eighth capacitor 1434f, a tenth inductor 1435f, an eleventh inductor 1436f, and a twelfth inductor 1437f; the first terminal of the tenth inductor 1435f is connected to the seventh terminal 1431f, and the second terminal of the tenth inductor 1435f is connected to the first terminal of the seventh capacitor 1433f and the first terminal of the eleventh inductor 1436f. The eleventh inductor 1436f's second terminal is connected to the first terminal of the eighth capacitor 1434f. The second terminal of the eighth capacitor 1434f and the second terminal of the seventh capacitor 1433f are together connected to the first terminal of the twelfth inductor 1437f. The second terminal of the twelfth inductor 1437f is connected to the eighth terminal 1432f. One of the seventh terminal 1431f and the eighth terminal 1432f is the input terminal of the fourth resonator 1430, and the other is the output terminal of the fourth resonator 1430.

[0245] The capacitance of the seventh capacitor (1433F) and the eighth capacitor (1434F) does not exceed 10pF. The capacitance of the seventh capacitor (1433F) and the eighth capacitor (1434F) can be between 0.01pF and 10pF. The capacitance of the seventh capacitor (1433F) can be either 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the eighth capacitor (1434F) can be either 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0246] The fourth resonator 1430 has a tenth inductor 1435f, an eleventh inductor 1436f, and a twelfth inductor 1437f, which provides three zeros for the first filter 1400. The inductance values ​​of the tenth inductor 1435f, the eleventh inductor 1436f, and the twelfth inductor 1437f do not exceed 10nH. The inductance values ​​of the tenth inductor 1435f, the eleventh inductor 1436f, and the twelfth inductor 1437f can be between 0.01nH and 10nH. The inductance value of the tenth inductor 1435f can be 0.01nH, the inductance value of the tenth inductor 1435f can be 10nH, and the inductance value of the tenth inductor 1435f can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the eleventh inductor 1436f can be 0.01nH, the inductance value of the eleventh inductor 1436f can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the twelfth inductor 1437f can be 0.01nH, the inductance value of the twelfth inductor 1437f can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0247] In one feasible implementation, the fourth resonator 1430 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the seventh terminal 1431f and the eighth terminal 1432f is connected to the output terminal of the first resonator 1410 or the output terminal of the third resonator 1420, and the other is connected to the second port 1200. In some embodiments, the fourth resonator 1430 can be connected in parallel with the first resonator 1410. For example, one of the seventh terminal 1431f and the eighth terminal 1432f is connected to the second port 1200, and the other is grounded.

[0248] In some embodiments, referring to FIG34, the fourth resonator 1430 includes a seventh terminal 1431g, an eighth terminal 1432g, a seventh capacitor 1433g, an eighth capacitor 1434g, a tenth inductor 1435g, an eleventh inductor 1436g, and a twelfth inductor 1437g; the first terminal of the tenth inductor 1435g is connected to the seventh terminal 1431g, and the second terminal of the tenth inductor 1435g is connected to the first terminal of the seventh capacitor 1433g and the first terminal of the eleventh inductor 1436g. The second terminal of the seventh capacitor 1433g and the second terminal of the eleventh inductor 1436g are connected to the first terminal of the eighth capacitor 1434g. The second terminal of the eighth capacitor 1434g is connected to the first terminal of the twelfth inductor 1437g. The second terminal of the twelfth inductor 1437g is connected to the eighth terminal 1432g. One of the seventh terminal 1431g and the eighth terminal 1432g is the input terminal of the fourth resonator 1430, and the other is the output terminal of the fourth resonator 1430.

[0249] The capacitance of the seventh capacitor (1433g) and the eighth capacitor (1434g) both do not exceed 10pF. The capacitance of the seventh capacitor (1433g) and the eighth capacitor (1434g) can be between 0.01pF and 10pF. The capacitance of the seventh capacitor (1433g) can be either 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the eighth capacitor (1434g) can be either 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0250] The fourth resonator 1430 has a tenth inductor 1435g, an eleventh inductor 1436g, and a twelfth inductor 1437g, which provides three zeros for the first filter 1400. The inductance values ​​of the tenth inductor 1435g, the eleventh inductor 1436g, and the twelfth inductor 1437g do not exceed 10nH. The inductance values ​​of the tenth inductor 1435g, the eleventh inductor 1436g, and the twelfth inductor 1437g can be between 0.01nH and 10nH. The inductance value of the tenth inductor 1435g can be 0.01nH, the inductance value of the tenth inductor 1435g can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the eleventh inductor 1436g can be 0.01nH, the inductance value of the eleventh inductor 1436g can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the twelfth inductor 1437g can be 0.01nH, the inductance value of the twelfth inductor 1437g can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0251] In one feasible implementation, the fourth resonator 1430 can be connected in series between the first resonator 1410 and the second port 1200. In this case, one of the seventh terminal 1431g and the eighth terminal 1432g is connected to the output terminal of the first resonator 1410 or the output terminal of the third resonator 1420, and the other is connected to the second port 1200. In some embodiments, the fourth resonator 1430 can be connected in parallel with the first resonator 1410. For example, one of the seventh terminal 1431g and the eighth terminal 1432g is connected to the second port 1200, and the other is grounded.

[0252] In some embodiments, referring to FIG18, the third resonator 1420 includes a fifth terminal, a sixth terminal, a seventh inductor, a fifth capacitor, and a sixth capacitor. The first terminal of the fifth capacitor and the first terminal of the seventh inductor are connected together to the fifth terminal. The second terminal of the fifth capacitor and the second terminal of the seventh inductor are connected together to the first terminal of the sixth capacitor. The second terminal of the sixth capacitor is connected to the sixth terminal. One of the fifth terminal and the sixth terminal is connected to the output terminal of the first resonator 1410, and the other is grounded. The fourth resonator 1430 includes a seventh terminal, an eighth terminal, a tenth inductor, a seventh capacitor, and an eighth capacitor. The first terminal of the seventh capacitor and the first terminal of the tenth inductor are connected together to the seventh terminal. The second terminal of the seventh capacitor and the second terminal of the tenth inductor are connected together to the first terminal of the eighth capacitor. The second terminal of the eighth capacitor is connected to the eighth terminal. One of the seventh terminal and the eighth terminal is connected to the output terminal of the first resonator 1410, and the other is connected to the second port 1200. In the first filter 1400, the first resonator 1410 and the fourth resonator 1430, which are connected in series, adopt the same topology. This makes it easier to control the admittance of the first filter 1400 and facilitates its mass production. Since one of the fifth and sixth terminals is connected to the output of the first resonator 1410 and the other is grounded, the third resonator 1420 can be connected in parallel with the first resonator 1410, which helps reduce the insertion loss of the first filter 1400 when transmitting radio frequency signals. The third resonator 1420 is composed of three reactive elements (seventh inductor, fifth capacitor, and sixth capacitor), and the fourth resonator 1430 is composed of three reactive elements (tenth inductor, seventh capacitor, and eighth capacitor). The third resonator 1420 and the fourth resonator 1430 have fewer reactive elements, which helps reduce the insertion loss of the multiplexer 1000.

[0253] In the first resonator, where, s=j2πf,Z C The impedance of the capacitor is represented by S, the complex frequency of the capacitor is represented by ω, the angular frequency of the first resonator is represented by f, the frequency of the first resonator is represented by c, and the capacitance value of the capacitor is represented by c.

[0254] In Formula 1. S1 represents the impedance of the first capacitor, S1 represents the complex frequency of the first resonator, ω1 represents the angular frequency of the first resonator, f1 represents the frequency of the first resonator, and c1 represents the capacitance of the first capacitor.

[0255] In Formula 2, S1 is used to characterize the impedance of the second capacitor, ω1 is used to characterize the complex frequency of the first resonator, f1 is used to characterize the frequency of the first resonator, and c2 is used to characterize the capacitance of the second capacitor.

[0256] In formula 3, S1 is used to characterize the impedance of the first inductor, S1 is used to characterize the complex frequency of the first resonator, ω1 is used to characterize the angular frequency of the first resonator, and L1 is used to characterize the inductance of the first inductor.

[0257] in,

[0258] Formula 5 is derived by combining Formulas 1 and 3 to characterize the impedance of the first capacitor and the second inductor connected in parallel.

[0259] Z1 is used to characterize the impedance of the first resonator.

[0260] Combining formulas 2, 5, and 6, we obtain formula 7.

[0261] Since the first resonator is connected in series between the first and second ports, when the impedance of the first resonator is infinite (the admittance of the first resonator is close to zero), the first resonator can effectively suppress the transmission of radio frequency signals from the first port to the second port, that is... At this time, the first resonator can effectively suppress the transmission of radio frequency signals from the first port to the second port.

[0262] Furthermore, since S1 = jω1, where j is an imaginary number.

[0263] ω1 has a positive solution, therefore, the first resonator can provide a zero point for the first filter.

[0264] When the impedance of the first resonator is zero, the first resonator provides a pole for the first filter.

[0265] Furthermore, since S1 = jω1, where j is an imaginary number.

[0266] Based on the above derivation process Where Z2 is used to characterize the impedance of the second resonator, S2 is used to characterize the complex frequency of the second resonator, S2=jω2, ω2 is used to characterize the angular frequency of the second filter, j is used to characterize the imaginary number, L4 is used to characterize the inductance value of the fourth inductor, C3 is used to characterize the third capacitor, and C4 is used to characterize the fourth capacitor.

[0267] The second resonator is connected in series between the first and third ports. When the impedance of the second resonator is infinite (the admittance of the second resonator is close to zero),

[0268] ω2 has a positive solution, and the second resonator can provide a zero point for the second filter.

[0269] When the impedance of the second resonator is zero, the second resonator provides a pole for the second filter.

[0270] In this application, a first resonator is connected in series between the first port and the second port, and a second resonator is connected in series between the first port and the third port, so that the admittances of the first resonator and the second resonator are matched, which can enable... or / and At this point, the second resonator can effectively suppress the radio frequency signal that can be transmitted from the first port to the second port. The first resonator can effectively suppress the radio frequency signal that can be transmitted from the first port to the third port.

[0271] The fourth resonator is connected in series between the first and second ports, and the fourth resonator can also provide a zero point for the first filter.

[0272] The third resonator can provide a zero point for the first filter. Z3 is used to characterize the impedance of the third resonator. Since the input terminal of the third resonator is connected to the output terminal of the first resonator, and the output terminal of the third resonator is grounded, the impedance of the third resonator is zero (the admittance of the third resonator is infinite), that is... The third resonator will short-circuit the first filter, thereby effectively suppressing the transmission of radio frequency signals from the first port to the second port. Furthermore, S3 = jω1, where j is an imaginary number.

[0273] ω1 has a positive solution, therefore, the third resonator can provide a zero point for the first filter.

[0274] In some embodiments, the second filter 1500 further includes a fifth resonator 1530, the input terminal of the fifth resonator 1530 is connected to the output terminal of the second resonator 1510, the output terminal of the second resonator 1510 is connected to the third port 1300, and the output terminal of the fifth resonator 1530 is grounded.

[0275] In some embodiments, the second filter 1500 further includes a fifth resonator 1530, the input terminal of the fifth resonator 1530 being connected to the input terminal of the second resonator 1510, and the output terminal of the fifth resonator 1530 being connected to the third port 1300.

[0276] In some embodiments, the second filter 1500 further includes a fifth resonator 1530 and a sixth resonator 1540. The sixth resonator 1540 is connected in series between the second resonator 1510 and the third port 1300. The input terminal of the fifth resonator 1530 is connected between the second resonator 1510 and the sixth resonator 1540, and the output terminal of the fifth resonator 1530 is grounded. The second filter 1500 can be a third-order filter. Third-order filters have fewer reactive components, which helps to reduce the insertion loss of the multiplexer 1000.

[0277] The fifth resonator 1530 can provide a zero point for the second filter 1500, and the input terminal of the fifth resonator 1530 is connected between the second resonator 1510 and the sixth resonator 1540. The output terminal of the fifth resonator 1530 is grounded. When the second filter 1500 transmits radio frequency signals, since the fifth resonator 1530 is not connected in series with the first port 1100 and the third port 1300, it is beneficial to reduce the insertion loss of the second filter 1500 when transmitting radio frequency signals. It should be noted that the second filter 1500 provided in this application has a total of four zeros. The second filter 1500 has more zeros, which enables the second filter 1500 to effectively suppress radio frequency signals outside the second frequency band. The second resonator 1510 provides a zero for the second filter 1500, the fifth resonator 1530 provides a zero for the second filter 1500, and the sixth resonator 1540 provides a zero for the second filter 1500. When the input terminal of the first resonator 1410 of the first filter 1400 and the input terminal of the second resonator 1510 of the second filter 1500 are connected to the first port 1100, the first filter 1400 can form a resonant cavity, providing an additional zero for the second filter 1500. When the input terminal of the first resonator 1410 of the first filter 1400 and the input terminal of the second resonator 1510 of the second filter 1500 are both connected to the first port 1100, the second filter 1500 can also form a resonant cavity, providing an additional zero point for the first filter 1400, thus enabling the first filter 1400 to have four zero points. Having more zero points allows the first filter 1400 to effectively suppress radio frequency signals outside the first frequency band.

[0278] In some embodiments, referring to FIG19, the second filter 1500 further includes a fifth resonator 1530 and a sixth resonator 1540. The input terminal of the fifth resonator 1530 is connected to the output terminal of the second resonator 1510, the output terminal of the fifth resonator 1530 is connected to the input terminal of the sixth resonator 1540, and the output terminal of the sixth resonator 1540 is connected to the third port 1300. The second filter 1500 can be a third-order filter. Third-order filters have fewer reactive components, which helps to reduce the insertion loss of the multiplexer 1000.

[0279] In some embodiments, referring to FIG20, the second filter 1500 further includes a fifth resonator 1530 and a sixth resonator 1540. The input terminal of the fifth resonator 1530 is connected to the output terminal of the second resonator 1510, and the output terminal of the fifth resonator 1530 and the input terminal of the sixth resonator 1540 are connected to the third port 1300. The output terminal of the sixth resonator 1540 is grounded. The second filter 1500 can be a third-order filter. Third-order filters have fewer reactive components, which helps to reduce the insertion loss of the multiplexer 1000. The third-order second filter 1500 has four zeros. The first filter 1400 can provide one zero for the second filter 1500, and the second resonator 1510, the fifth resonator 1530, and the sixth resonator 1540 each provide one zero for the second filter 1500. The input terminal of the sixth resonator 1540 is connected to the output terminal of the fifth resonator 1530, and the output terminal of the sixth resonator 1540 is grounded. When the second filter 1500 transmits radio frequency signals, since the sixth resonator 1540 is not connected in series with the first port 1100 and the third port 1300, it is beneficial to reduce the insertion loss of the second filter 1500 when transmitting radio frequency signals.

[0280] Please refer to Figures 35-41. The fifth resonator 1530 includes one of the following structures:

[0281] In some embodiments, referring to FIG35, the fifth resonator 1530 includes a ninth terminal 1531a, a tenth terminal 1532a, a thirteenth inductor 1535a, a ninth capacitor 1533a, and a tenth capacitor 1534a. The first terminal of the ninth capacitor 1533a and the first terminal of the thirteenth inductor 1535a are connected to the ninth terminal 1531a. The second terminal of the ninth capacitor 1533a and the second terminal of the thirteenth inductor 1535a are connected to the first terminal of the tenth capacitor 1534a. The second terminal of the tenth capacitor 1534a is connected to the tenth terminal 1532a. One of the ninth terminal 1531a and the tenth terminal 1532a is the input terminal of the fifth resonator 1530, and the other is the output terminal of the fifth resonator 1530.

[0282] The capacitance of the ninth capacitor 1533a and the tenth capacitor 1534a does not exceed 10pF. The capacitance of the ninth capacitor 1533a and the tenth capacitor 1534a can be between 0.01pF and 10pF. The capacitance of the ninth capacitor 1533a can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the tenth capacitor 1534a can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0283] The fifth resonator 1530 has a thirteenth inductor 1535a, which provides a zero point for the second filter 1500. The inductance value of the thirteenth inductor 1535a does not exceed 10nH, and can be between 0.01nH and 10nH. The inductance value of the thirteenth inductor 1535a can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0284] In one feasible implementation, the fifth resonator 1530 can be connected in series between the second resonator 1510 and the second port 1200. In this case, one of the ninth terminal 1531a and the tenth terminal 1532a is connected to the output of the second resonator 1510, and the other is connected to the third port 1300. In some embodiments, one of the ninth terminal 1531a and the tenth terminal 1532a is connected to the output of the second resonator 1510, and the other is grounded.

[0285] In some embodiments, referring to FIG36, the fifth resonator 1530 includes a ninth terminal 1531b, a tenth terminal 1532b, a thirteenth inductor 1535b, a ninth capacitor 1533b, and a tenth capacitor 1534b. The first terminal of the ninth capacitor 1533b and the first terminal of the thirteenth inductor 1535b are connected to the ninth terminal 1531b. The second terminal of the thirteenth inductor 1535b is connected to the first terminal of the tenth capacitor 1534b. The second terminal of the ninth capacitor 1533b and the second terminal of the tenth capacitor 1534b are connected to the tenth terminal 1532b. One of the ninth terminal 1531b and the tenth terminal 1532b is the input terminal of the fifth resonator 1530, and the other is the output terminal of the fifth resonator 1530.

[0286] The capacitance of the ninth capacitor 1533b and the tenth capacitor 1534b shall not exceed 10pF. The capacitance of the ninth capacitor 1533b and the tenth capacitor 1534b may be between 0.01pF and 10pF. The capacitance of the ninth capacitor 1533b may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the tenth capacitor 1534b may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0287] The fifth resonator 1530 has a thirteenth inductor 1535b, which provides a zero point for the second filter 1500. The inductance value of the thirteenth inductor 1535b does not exceed 10nH, and can be between 0.01nH and 10nH. The inductance value of the thirteenth inductor 1535b can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0288] In one feasible implementation, the fifth resonator 1530 can be connected in series between the second resonator 1510 and the third port 1300. In this case, one of the ninth terminal 1531b and the tenth terminal 1532b is connected to the output of the second resonator 1510, and the other is connected to the third port 1300. In some embodiments, one of the ninth terminal 1531b and the tenth terminal 1532b is connected to the output of the second resonator 1510, and the other is grounded.

[0289] In some embodiments, referring to FIG37, the fifth resonator 1530 includes a ninth terminal 1531c, a tenth terminal 1532c, a ninth capacitor 1533c, a tenth capacitor 1534c, a thirteenth inductor 1535c, and a fourteenth inductor 1536c; the first terminals of the ninth capacitor 1533c and the thirteenth inductor 1535c are connected to the ninth terminal 1531c, the second terminals of the ninth capacitor 1533c and the thirteenth inductor 1535c are connected to the first terminal of the ninth capacitor 1533c, the second terminal of the tenth capacitor is connected to the first terminal of the fourteenth inductor 1536c, and the second terminal of the fourteenth inductor 1536c is connected to the tenth terminal 1532c; one of the ninth terminal 1531c and the tenth terminal 1532c is the input terminal of the fifth resonator 1530, and the other is the output terminal of the fifth resonator 1530.

[0290] The capacitance of the ninth capacitor 1533c and the tenth capacitor 1534c does not exceed 10pF. The capacitance of the ninth capacitor 1533c and the tenth capacitor 1534c can be between 0.01pF and 10pF. The capacitance of the ninth capacitor 1533c can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the tenth capacitor 1534c can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0291] The fifth resonator 1530 has a thirteenth inductor 1535c and a fourteenth inductor 1536c, which can provide two zeros for the second filter 1500. The inductance values ​​of the thirteenth inductor 1535c and the fourteenth inductor 1536c do not exceed 10nH, the inductance values ​​of the thirteenth inductor 1535c and the fourteenth inductor 1536c can be between 0.01nH and 10nH, the inductance value of the thirteenth inductor 1535c can be 0.01nH, the inductance value of the thirteenth inductor 1535c can be 10nH, and the inductance value of the thirteenth inductor 1535c can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the fourteenth inductor 1536c can be 0.01nH, the inductance value of the fourteenth inductor 1536c can be 10nH, or the inductance value of the fourteenth inductor 1536c can be any value from 0.01nH to 10nH (e.g., 5nH).

[0292] In one feasible implementation, the fifth resonator 1530 can be connected in series between the second resonator 1510 and the third port 1300. In this case, one of the ninth terminal 1531c and the tenth terminal 1532c is connected to the output of the second resonator 1510, and the other is connected to the third port 1300. In some embodiments, one of the ninth terminal 1531c and the tenth terminal 1532c is connected to the output of the first resonator 1410, and the other is grounded.

[0293] In some embodiments, referring to FIG38, the fifth resonator 1530 includes a ninth terminal 1531d, a tenth terminal 1532d, a ninth capacitor 1533d, a tenth capacitor 1534d, a thirteenth inductor 1535d, and a fourteenth inductor 1536d; the first end of the thirteenth inductor 1535d is connected to the ninth terminal 1531d, the second end of the thirteenth inductor 1535d is connected to the first end of the ninth capacitor 1533d and the first end of the fourteenth inductor 1536d, the second ends of the ninth capacitor 1533d and the fourteenth inductor 1536d are jointly connected to the first end of the tenth capacitor 1534d, and the second end of the tenth capacitor 1534d is connected to the tenth terminal 1532d; one of the ninth terminal 1531d and the tenth terminal 1532d is the input terminal of the fifth resonator 1530, and the other is the output terminal of the fifth resonator 1530.

[0294] The capacitance of the ninth capacitor 1533d and the tenth capacitor 1534d does not exceed 10pF. The capacitance of the ninth capacitor 1533d and the tenth capacitor 1534d can be between 0.01pF and 10pF. The capacitance of the ninth capacitor 1533d can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the tenth capacitor 1534d can be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0295] The fifth resonator 1530 has a thirteenth inductor 1535d and a fourteenth inductor 1536d, which can provide two zeros for the second filter 1500. The inductance values ​​of the thirteenth inductor 1535d and the fourteenth inductor 1536d do not exceed 10nH, the inductance values ​​of the thirteenth inductor 1535d and the fourteenth inductor 1536d can be between 0.01nH and 10nH, the inductance value of the thirteenth inductor 1535d can be 0.01nH, the inductance value of the thirteenth inductor 1535d can be 10nH, and the inductance value of the thirteenth inductor 1535d can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the fourteenth inductor 1536d can be 0.01nH, the inductance value of the fourteenth inductor 1536d can be 10nH, or the inductance value of the fourteenth inductor 1536d can be any value from 0.01nH to 10nH (e.g., 5nH).

[0296] In one feasible implementation, the fifth resonator 1530 can be connected in series between the second resonator 1510 and the third port 1300. In this case, one of the ninth terminal 1531d and the tenth terminal 1532d is connected to the output of the second resonator 1510, and the other is connected to the third port 1300. In some embodiments, one of the ninth terminal 1531d and the tenth terminal 1532d is connected to the output of the first resonator 1410, and the other is grounded.

[0297] In some embodiments, referring to FIG39, the fifth resonator 1530 includes a ninth terminal 1531e, a tenth terminal 1532e, a ninth capacitor 1533e, a tenth capacitor 1534e, a thirteenth inductor 1535e, and a fourteenth inductor 1536e; the first end of the thirteenth inductor 1535e is connected to the ninth terminal 1531e, the second end of the thirteenth inductor 1535e is connected to the first end of the ninth capacitor 1533e and the first end of the fourteenth inductor 1536e, the second end of the fourteenth inductor 1536e is connected to the first end of the tenth capacitor 1534e, and the second ends of the ninth capacitor 1533e and the tenth capacitor 1534e are jointly connected to the tenth terminal 1532e; one of the ninth terminal 1531e and the tenth terminal 1532e is the input terminal of the fifth resonator 1530, and the other is the output terminal of the fifth resonator 1530.

[0298] The capacitance of the ninth capacitor 1533e and the tenth capacitor 1534e shall not exceed 10pF. The capacitance of the ninth capacitor 1533e and the tenth capacitor 1534e may be between 0.01pF and 10pF. The capacitance of the ninth capacitor 1533e may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the tenth capacitor 1534e may be 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0299] The fifth resonator 1530 has a thirteenth inductor 1535e and a fourteenth inductor 1536e, which can provide two zeros for the second filter 1500. The inductance values ​​of the thirteenth inductor 1535e and the fourteenth inductor 1536e do not exceed 10nH, the inductance values ​​of the thirteenth inductor 1535e and the fourteenth inductor 1536e can be between 0.01nH and 10nH, the inductance value of the thirteenth inductor 1535e can be 0.01nH, the inductance value of the thirteenth inductor 1535e can be 10nH, and the inductance value of the thirteenth inductor 1535e can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the fourteenth inductor 1536e can be 0.01nH, the inductance value of the fourteenth inductor 1536e can be 10nH, or the inductance value of the fourteenth inductor 1536e can be any value from 0.01nH to 10nH (e.g., 5nH).

[0300] In one feasible implementation, the fifth resonator 1530 can be connected in series between the second resonator 1510 and the third port 1300. In this case, one of the ninth terminal 1531e and the tenth terminal 1532e is connected to the output of the second resonator 1510, and the other is connected to the third port 1300. In some embodiments, one of the ninth terminal 1531e and the tenth terminal 1532e is connected to the output of the first resonator 1410, and the other is grounded.

[0301] In some embodiments, referring to FIG40, the fifth resonator 1530 includes a ninth terminal 1531f, a tenth terminal 1532f, a ninth capacitor 1533f, a tenth capacitor 1534f, a thirteenth inductor 1535f, a fourteenth inductor 1536f, and a fifteenth inductor 1537f; the first terminal of the thirteenth inductor 1535f is connected to the ninth terminal 1531f, and the second terminal of the thirteenth inductor 1535f is connected to the first terminal of the ninth capacitor 1533f and the fourteenth inductor 1536f. The first terminal is connected, the second terminal of the fourteenth inductor 1536f is connected to the first terminal of the tenth capacitor 1534f, the second terminal of the tenth capacitor 1534f and the second terminal of the ninth capacitor 1533f are connected together to the first terminal of the fifteenth inductor 1537f, and the second terminal of the fifteenth inductor 1537f is connected to the tenth terminal 1532f; one of the ninth terminal 1531f and the tenth terminal 1532f is the input terminal of the fifth resonator 1530, and the other is the output terminal of the fifth resonator 1530.

[0302] The capacitance of the ninth capacitor (1533F) and the tenth capacitor (1534F) shall not exceed 10pF. The capacitance of the ninth capacitor (1533F) and the tenth capacitor (1534F) can be between 0.01pF and 10pF. The capacitance of the ninth capacitor (1533F) can be either 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the tenth capacitor (1534F) can be either 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0303] The fifth resonator 1530 has a thirteenth inductor 1535f, a fourteenth inductor 1536f, and a fifteenth inductor 1537f. The fifth resonator 1530 can provide three zeros for the second filter 1500. The inductance values ​​of the thirteenth inductor 1535f, the fourteenth inductor 1536f, and the fifteenth inductor 1537f do not exceed 10nH. The inductance values ​​of the thirteenth inductor 1535f, the fourteenth inductor 1536f, and the fifteenth inductor 1537f can be between 0.01nH and 10nH. The inductance value of the thirteenth inductor 1535f can be 0.01nH, the inductance value of the thirteenth inductor 1535f can be 10nH, and the inductance value of the thirteenth inductor 1535f can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the fourteenth inductor 1536f can be 0.01nH, the inductance value of the fourteenth inductor 1536f can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the fifteenth inductor 1537f can be 0.01nH, the inductance value of the fifteenth inductor 1537f can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0304] In one feasible implementation, the fifth resonator 1530 can be connected in series between the second resonator 1510 and the third port 1300. In this case, one of the ninth terminal 1531f and the tenth terminal 1532f is connected to the output of the second resonator 1510, and the other is connected to the third port 1300. In some embodiments, one of the ninth terminal 1531f and the tenth terminal 1532f is connected to the output of the first resonator 1410, and the other is grounded.

[0305] In some embodiments, referring to FIG41, the fifth resonator 1530 includes a ninth terminal 1531g, a tenth terminal 1532g, a ninth capacitor 1533g, a tenth capacitor 1534g, a thirteenth inductor 1535g, a fourteenth inductor 1536g, and a fifteenth inductor 1537g; the first terminal of the thirteenth inductor 1535g is connected to the ninth terminal 1531g, and the second terminal of the thirteenth inductor 1535g is connected to the first terminal of the ninth capacitor 1533g and the fourteenth inductor 1536g. The first terminal is connected, the second terminal of the ninth capacitor 1533g and the second terminal of the fourteenth inductor 1536g are connected together to the first terminal of the tenth capacitor 1534g, the second terminal of the tenth capacitor 1534g is connected to the first terminal of the fifteenth inductor 1537g, the second terminal of the fifteenth inductor 1537g is connected to the tenth terminal 1532g, one of the ninth terminal 1531g and the tenth terminal 1532g is the input terminal of the fifth resonator 1530, and the other is the output terminal of the fifth resonator 1530.

[0306] The capacitance of the ninth capacitor (1533g) and the tenth capacitor (1534g) does not exceed 10pF. The capacitance of the ninth capacitor (1533g) and the tenth capacitor (1534g) can be between 0.01pF and 10pF. The capacitance of the ninth capacitor (1533g) can be either 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the tenth capacitor (1534g) can be either 0.01pF, 10pF, or any value from 0.01pF to 10pF (e.g., 5pF).

[0307] The fifth resonator 1530 has a thirteenth inductor 1535g, a fourteenth inductor 1536g, and a fifteenth inductor 1537g. The fifth resonator 1530 can provide three zeros for the second filter 1500. The inductance values ​​of the thirteenth inductor 1535g, the fourteenth inductor 1536g, and the fifteenth inductor 1537g do not exceed 10nH. The inductance values ​​of the thirteenth inductor 1535g, the fourteenth inductor 1536g, and the fifteenth inductor 1537g can be between 0.01nH and 10nH. The inductance value of the thirteenth inductor 1535g can be 0.01nH, the inductance value of the thirteenth inductor 1535g can be 10nH, and the inductance value of the thirteenth inductor 1535g can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the fourteenth inductor 1536g can be 0.01nH, the inductance value of the fourteenth inductor 1536g can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the fifteenth inductor 1537g can be 0.01nH, the inductance value of the fifteenth inductor 1537g can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0308] In one feasible implementation, the fifth resonator 1530 can be connected in series between the second resonator 1510 and the third port 1300. In this case, one of the ninth terminal 1531g and the tenth terminal 1532g is connected to the output of the second resonator 1510, and the other is connected to the third port 1300. In some embodiments, one of the ninth terminal 1531g and the tenth terminal 1532g is connected to the output of the first resonator 1410, and the other is grounded.

[0309] Please refer to Figures 42-48. The sixth resonator 1540 includes one of the following structures:

[0310] In some embodiments, referring to FIG42, the sixth resonator 1540 includes an eleventh terminal 1541a, a twelfth terminal 1542a, a sixteenth inductor 1545a, an eleventh capacitor 1543a, and a twelfth capacitor 1544a. The first ends of the eleventh capacitor 1543a and the sixteenth inductor 1545a are connected to the eleventh terminal 1541a. The second ends of the eleventh capacitor 1543a and the sixteenth inductor 1545a are connected to the first end of the twelfth capacitor 1544a. The second end of the twelfth capacitor 1544a is connected to the twelfth terminal 1542a. One of the eleventh terminal 1541a and the twelfth terminal 1542a is the input terminal of the sixth resonator 1540, and the other is the output terminal of the sixth resonator 1540.

[0311] The capacitance of the eleventh capacitor (1543a) and the twelfth capacitor (1544a) shall not exceed 10pF. The capacitance of the eleventh capacitor (1543a) and the twelfth capacitor (1544a) may be between 0.01pF and 10pF. The capacitance of the eleventh capacitor (1543a) may be 0.01pF, and the capacitance of the eleventh capacitor (1543a) may be 10pF. The capacitance of the eleventh capacitor (1543a) may be any value from 0.01pF to 10pF (e.g., 5pF).

[0312] The sixth resonator 1540 has a sixteenth inductor 1545a, which provides a zero point for the second filter 1500. The inductance value of the sixteenth inductor 1545a does not exceed 10nH, and can be between 0.01nH and 10nH. The inductance value of the sixteenth inductor 1545a can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0313] In one possible implementation, the sixth resonator 1540 can be connected in series between the second resonator 1510 and the third port 1300. In this case, one of the eleventh and twelfth terminals is connected to the output of the second resonator 1510 or the output of the fifth resonator 1530, and the other is connected to the third port 1300. In some embodiments, the sixth resonator 1540 can be connected in parallel with the second resonator 1510. For example, one of the eleventh and twelfth terminals is connected to the third port 1300, and the other is grounded.

[0314] In some embodiments, referring to FIG43, the sixth resonator 1540 includes an eleventh terminal 1541b, a twelfth terminal 1542b, a sixteenth inductor 1545b, an eleventh capacitor 1543b, and a twelfth capacitor 1544b. The first ends of the eleventh capacitor 1543b and the first ends of the sixteenth inductor 1545b are connected to the eleventh terminal. The second end of the sixteenth inductor 1545b is connected to the first end of the twelfth capacitor 1544b. The second ends of the eleventh capacitor 1543b and the second ends of the twelfth capacitor 1544b are connected to the twelfth terminal. One of the eleventh terminal and the twelfth terminal is the input terminal of the sixth resonator 1540, and the other is the output terminal of the sixth resonator 1540.

[0315] The capacitance of the eleventh capacitor 1543b and the twelfth capacitor 1544b shall not exceed 10pF. The capacitance of the eleventh capacitor 1543b and the twelfth capacitor 1544b may be between 0.01pF and 10pF. The capacitance of the eleventh capacitor 1543b may be 0.01pF, and the capacitance of the eleventh capacitor 1543b may be 10pF. The capacitance of the eleventh capacitor 1543b may be any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the twelfth capacitor 1544b may be 0.01pF, and the capacitance of the twelfth capacitor 1544b may be 10pF. The capacitance of the twelfth capacitor 1544b may be any value from 0.01pF to 10pF (e.g., 5pF).

[0316] The sixth resonator 1540 has a sixteenth inductor 1545b, which provides a zero point for the second filter 1500. The inductance value of the sixteenth inductor 1545b does not exceed 10nH, and can be between 0.01nH and 10nH. The inductance value of the sixteenth inductor 1545b can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0317] In one possible implementation, the sixth resonator 1540 can be connected in series between the second resonator 1510 and the third port 1300. In this case, one of the eleventh and twelfth terminals is connected to the output of the second resonator 1510 or the output of the fifth resonator 1530, and the other is connected to the third port 1300. In some embodiments, the sixth resonator 1540 can be connected in parallel with the second resonator 1510. For example, one of the eleventh and twelfth terminals is connected to the third port 1300, and the other is grounded.

[0318] In some embodiments, referring to FIG44, the sixth resonator 1540 includes an eleventh terminal 1541c, a twelfth terminal 1542c, an eleventh capacitor 1543c, a twelfth capacitor 1544c, a sixteenth inductor 1545c, and a seventeenth inductor 1546c; the first ends of the eleventh capacitor 1543c and the first ends of the sixteenth inductor 1545c are connected to the eleventh terminal, the second ends of the eleventh capacitor 1543c and the second ends of the sixteenth inductor 1544c are connected to the first end of the eleventh capacitor 1543c, the second end of the twelfth capacitor is connected to the first end of the seventeenth inductor 1546c, and the second end of the seventeenth inductor 1546c is connected to the twelfth terminal; one of the eleventh terminal and the twelfth terminal is the input terminal of the sixth resonator 1540, and the other is the output terminal of the sixth resonator 1540.

[0319] The capacitance of the eleventh capacitor (1543c) and the twelfth capacitor (1544c) does not exceed 10pF. The capacitance of the eleventh capacitor (1543c) and the twelfth capacitor (1544c) can be between 0.01pF and 10pF. The capacitance of the eleventh capacitor (1543c) can be 0.01pF, and the capacitance of the eleventh capacitor (1543c) can be 10pF. The capacitance of the eleventh capacitor (1543c) can be any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the twelfth capacitor (1544c) can be 0.01pF, and the capacitance of the twelfth capacitor (1544c) can be 10pF. The capacitance of the twelfth capacitor (1544c) can be any value from 0.01pF to 10pF (e.g., 5pF).

[0320] The sixth resonator 1540 has a sixteenth inductor 1545c and a seventeenth inductor 1546c, which can provide two zeros for the second filter 1500. The inductance values ​​of the sixteenth inductor 1545c and the seventeenth inductor 1546c do not exceed 10nH, and the inductance values ​​of the sixteenth inductor 1545c and the seventeenth inductor 1546c can be between 0.01nH and 10nH. The inductance value of the sixteenth inductor 1545c can be 0.01nH, the inductance value of the sixteenth inductor 1545c can be 10nH, and the inductance value of the sixteenth inductor 1545c can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the seventeenth inductor 1546c can be 0.01nH, the inductance value of the seventeenth inductor 1546c can be 10nH, or the inductance value of the seventeenth inductor 1546c can be any value from 0.01nH to 10nH (e.g., 5nH).

[0321] In one possible implementation, the sixth resonator 1540 can be connected in series between the second resonator 1510 and the third port 1300. In this case, one of the eleventh and twelfth terminals is connected to the output of the second resonator 1510 or the output of the fifth resonator 1530, and the other is connected to the third port 1300. In some embodiments, the sixth resonator 1540 can be connected in parallel with the second resonator 1510. For example, one of the eleventh and twelfth terminals is connected to the third port 1300, and the other is grounded.

[0322] In some embodiments, referring to FIG45, the sixth resonator 1540 includes an eleventh terminal 1541d, a twelfth terminal 1542d, an eleventh capacitor 1543d, a twelfth capacitor 1544d, a sixteenth inductor 1545d, and a seventeenth inductor 1546d; the first end of the sixteenth inductor 1545d is connected to the eleventh terminal, the second end of the sixteenth inductor 1545d is connected to the first end of the eleventh capacitor 1543d and the first end of the seventeenth inductor 1546d, the second ends of the eleventh capacitor 1543d and the seventeenth inductor 1546d are jointly connected to the first end of the twelfth capacitor 1544d, and the second end of the twelfth capacitor 1544d is connected to the twelfth terminal; one of the eleventh terminal and the twelfth terminal is the input terminal of the sixth resonator 1540, and the other is the output terminal of the sixth resonator 1540.

[0323] The capacitance of the eleventh capacitor (1543d) and the twelfth capacitor (1544d) does not exceed 10pF. The capacitance of the eleventh capacitor (1543d) and the twelfth capacitor (1544d) can be between 0.01pF and 10pF. The capacitance of the eleventh capacitor (1543d) can be 0.01pF, and the capacitance of the eleventh capacitor (1543d) can be 10pF. The capacitance of the eleventh capacitor (1543d) can be any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the twelfth capacitor (1544d) can be 0.01pF, and the capacitance of the twelfth capacitor (1544d) can be 10pF. The capacitance of the twelfth capacitor (1544d) can be any value from 0.01pF to 10pF (e.g., 5pF).

[0324] The sixth resonator 1540 has a sixteenth inductor 1545d and a seventeenth inductor 1546d, which can provide two zeros for the second filter 1500. The inductance values ​​of the sixteenth inductor 1545d and the seventeenth inductor 1546d do not exceed 10nH, and the inductance values ​​of the sixteenth inductor 1545d and the seventeenth inductor 1546d can be between 0.01nH and 10nH. The inductance value of the sixteenth inductor 1545d can be 0.01nH, the inductance value of the sixteenth inductor 1545d can be 10nH, and the inductance value of the sixteenth inductor 1545d can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the seventeenth inductor 1546d can be 0.01nH, the inductance value of the seventeenth inductor 1546d can be 10nH, or the inductance value of the seventeenth inductor 1546d can be any value from 0.01nH to 10nH (e.g., 5nH).

[0325] In one implementation, the sixth resonator 1540 can be connected in series between the second resonator 1510 and the third port 1300. In this case, one of the eleventh and twelfth terminals is connected to the output of the second resonator 1510 or the output of the fifth resonator 1530, and the other is connected to the third port 1300. In some embodiments, the sixth resonator 1540 can be connected in parallel with the second resonator 1510. For example, one of the eleventh and twelfth terminals is connected to the third port 1300, and the other is grounded.

[0326] In some embodiments, referring to FIG46, the sixth resonator 1540 includes an eleventh terminal 1541e, a twelfth terminal 1542e, an eleventh capacitor 1543e, a twelfth capacitor 1544e, a sixteenth inductor 1545e, and a seventeenth inductor 1546e; the first end of the sixteenth inductor 1545e is connected to the eleventh terminal, the second end of the sixteenth inductor 1545e is connected to the first end of the eleventh capacitor 1543e and the first end of the seventeenth inductor 1546e, the second end of the seventeenth inductor 1546e is connected to the first end of the twelfth capacitor 1544e, and the second ends of the eleventh capacitor 1543e and the twelfth capacitor 1544e are jointly connected to the twelfth terminal; one of the eleventh terminal and the twelfth terminal is the input terminal of the sixth resonator 1540, and the other is the output terminal of the sixth resonator 1540.

[0327] The capacitance of the eleventh capacitor (1543e) and the twelfth capacitor (1544e) does not exceed 10pF. The capacitance of the eleventh capacitor (1543e) and the twelfth capacitor (1544e) can be between 0.01pF and 10pF. The capacitance of the eleventh capacitor (1543e) can be 0.01pF, and the capacitance of the eleventh capacitor (1543e) can be 10pF. The capacitance of the eleventh capacitor (1543e) can be any value from 0.01pF to 10pF (e.g., 5pF). Similarly, the capacitance of the twelfth capacitor (1544e) can be 0.01pF, and the capacitance of the twelfth capacitor (1544e) can be 10pF. The capacitance of the twelfth capacitor (1544e) can be any value from 0.01pF to 10pF (e.g., 5pF).

[0328] The sixth resonator 1540 has a sixteenth inductor 1545e and a seventeenth inductor 1546e, which can provide two zeros for the second filter 1500. The inductance values ​​of the sixteenth inductor 1545e and the seventeenth inductor 1546e do not exceed 10nH, and the inductance values ​​of the sixteenth inductor 1545e and the seventeenth inductor 1546e can be between 0.01nH and 10nH. The inductance value of the sixteenth inductor 1545e can be 0.01nH, the inductance value of the sixteenth inductor 1545e can be 10nH, and the inductance value of the sixteenth inductor 1545e can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the seventeenth inductor 1546e can be 0.01nH, the inductance value of the seventeenth inductor 1546e can be 10nH, or the inductance value of the seventeenth inductor 1546e can be any value from 0.01nH to 10nH (e.g., 5nH).

[0329] In one possible implementation, the sixth resonator 1540 can be connected in series between the second resonator 1510 and the third port 1300. In this case, one of the eleventh and twelfth terminals is connected to the output of the second resonator 1510 or the output of the fifth resonator 1530, and the other is connected to the third port 1300. In some embodiments, the sixth resonator 1540 can be connected in parallel with the second resonator 1510. For example, one of the eleventh and twelfth terminals is connected to the third port 1300, and the other is grounded.

[0330] In some embodiments, referring to FIG47, the sixth resonator 1540 includes an eleventh terminal 1541f, a twelfth terminal 1542f, an eleventh capacitor 1543f, a twelfth capacitor 1544f, a sixteenth inductor 1545f, a seventeenth inductor 1546f, and an eighteenth inductor 1547f; the first terminal of the sixteenth inductor 1545f is connected to the eleventh terminal, the second terminal of the sixteenth inductor 1545f is connected to the first terminals of the eleventh capacitor 1543f and the seventeenth inductor 1546f, the second terminal of the seventeenth inductor 1546f is connected to the first terminal of the twelfth capacitor 1544f, the second terminal of the twelfth capacitor 1544f and the second terminal of the eleventh capacitor 1543f are jointly connected to the first terminal of the eighteenth inductor 1547f, and the second terminal of the eighteenth inductor 1547f is connected to the twelfth terminal; one of the eleventh terminal and the twelfth terminal is the input terminal of the sixth resonator 1540, and the other is the output terminal of the sixth resonator 1540.

[0331] The capacitance of the eleventh capacitor 1543F and the twelfth capacitor 1544F both do not exceed 10pF. The capacitance of the eleventh capacitor 1543F and the twelfth capacitor 1544F can be between 0.01pF and 10pF. The capacitance of the eleventh capacitor 1543F can be 0.01pF, and the capacitance of the eleventh capacitor 1543D can be 10pF. The capacitance of the eleventh capacitor 1543F can be any value from 0.01pF to 10pF (e.g., 5pF). The capacitance of the twelfth capacitor 1544F can be 0.01pF, and the capacitance of the twelfth capacitor 1544F can be 10pF. The capacitance of the twelfth capacitor 1544F can be any value from 0.01pF to 10pF (e.g., 5pF).

[0332] The sixth resonator 1540 has a sixteenth inductor 1545f, a seventeenth inductor 1546f, and an eighteenth inductor 1547f. The sixth resonator 1540 can provide three zeros for the second filter 1500. The inductance values ​​of the sixteenth inductor 1545f, seventeenth inductor 1546f, and eighteenth inductor 1547f do not exceed 10nH. The inductance values ​​of the sixteenth inductor 1545f, seventeenth inductor 1546f, and eighteenth inductor 1547f can be between 0.01nH and 10nH. The inductance value of the sixteenth inductor 1545f can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the seventeenth inductor 1546f can be 0.01nH, the inductance value of the seventeenth inductor 1546f can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the eighteenth inductor 1547f can be 0.01nH, the inductance value of the eighteenth inductor 1547f can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0333] In one possible implementation, the sixth resonator 1540 can be connected in series between the second resonator 1510 and the third port 1300. In this case, one of the eleventh and twelfth terminals is connected to the output of the second resonator 1510 or the output of the fifth resonator 1530, and the other is connected to the third port 1300. In some embodiments, the sixth resonator 1540 can be connected in parallel with the second resonator 1510. For example, one of the eleventh and twelfth terminals is connected to the third port 1300, and the other is grounded.

[0334] In some embodiments, referring to FIG48, the sixth resonator 1540 includes an eleventh terminal 1541g, a twelfth terminal 1542g, an eleventh capacitor 1543g, a twelfth capacitor 1544g, a sixteenth inductor 1545g, a seventeenth inductor 1546g, and an eighteenth inductor 1547g; the first end of the sixteenth inductor 1545g is connected to the eleventh terminal, the second end of the sixteenth inductor 1545g is connected to the first ends of the eleventh capacitor 1543g and the seventeenth inductor 1546g, the second ends of the eleventh capacitor 1543g and the seventeenth inductor 1546g are jointly connected to the first end of the twelfth capacitor 1544g, the second end of the twelfth capacitor 1544g is connected to the first end of the eighteenth inductor 1547g, and the second end of the eighteenth inductor 1547g is connected to the twelfth terminal. One of the eleventh terminal and the twelfth terminal is the input terminal of the sixth resonator 1540, and the other is the output terminal of the sixth resonator 1540.

[0335] The capacitance of the eleventh capacitor (1543g) and the twelfth capacitor (1544g) does not exceed 10pF. The capacitance of the eleventh capacitor (1543g) and the twelfth capacitor (1544g) can be between 0.01pF and 10pF. The capacitance of the eleventh capacitor (1543g) can be 0.01pF, and the capacitance of the eleventh capacitor (1543g) can be 10pF. The capacitance of the eleventh capacitor (1544g) can be any value from 0.01pF to 10pF (e.g., 5pF).

[0336] The sixth resonator 1540 has a sixteenth inductor 1545g, a seventeenth inductor 1546g, and an eighteenth inductor 1547g. The sixth resonator 1540 can provide three zeros for the second filter 1500. The inductance values ​​of the sixteenth inductor 1545g, seventeenth inductor 1546g, and eighteenth inductor 1547g do not exceed 10nH. The inductance values ​​of the sixteenth inductor 1545g, seventeenth inductor 1546g, and eighteenth inductor 1547g can be between 0.01nH and 10nH. The inductance value of the sixteenth inductor 1545g can be 0.01nH, the inductance value of the sixteenth inductor 1545g can be 10nH, and the inductance value of the sixteenth inductor 1545g can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the seventeenth inductor 1546g can be 0.01nH, the inductance value of the seventeenth inductor 1546g can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the eighteenth inductor 1547g can be 0.01nH, the inductance value of the eighteenth inductor 1547g can be 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0337] In one possible implementation, the sixth resonator 1540 can be connected in series between the second resonator 1510 and the third port 1300. In this case, one of the eleventh and twelfth terminals is connected to the output of the second resonator 1510 or the output of the fifth resonator 1530, and the other is connected to the third port 1300. In some embodiments, the sixth resonator 1540 can be connected in parallel with the second resonator 1510. For example, one of the eleventh and twelfth terminals is connected to the third port 1300, and the other is grounded.

[0338] In some embodiments, the first filter 1400 includes a first resonator 1410, a third resonator 1420, and a fourth resonator 1430. The input terminal of the first resonator 1410 is connected to the first port 1100. The fourth resonator 1430 is connected in series between the first resonator 1410 and the second port 1200. The input terminal of the third resonator 1420 is connected between the first resonator 1410 and the fourth resonator 1430. The output terminal of the third resonator 1420 is grounded. The second filter 1500 includes a second resonator 1510, a fifth resonator 1530, and a sixth resonator 1540. The input terminal of the second resonator 1510 is connected to the first port 1100. The sixth resonator 1540 is connected in series between the second resonator 1510 and the third port 1300. The input terminal of the fifth resonator 1530 is connected between the output terminal of the second resonator 1510 and the input terminal of the sixth resonator 1540. The output terminal of the fifth resonator 1530 is grounded. The fifth resonator 1530 includes a ninth terminal, a tenth terminal, a thirteenth inductor, a ninth capacitor, and a tenth capacitor. The first terminal of the ninth capacitor and the first terminal of the thirteenth inductor are connected to the ninth terminal. The second terminal of the ninth capacitor and the second terminal of the thirteenth inductor are connected to the first terminal of the tenth capacitor. The second terminal of the tenth capacitor is connected to the tenth terminal. One of the ninth and tenth terminals is connected to the output terminal of the second resonator 1510, and the other is grounded. The sixth resonator 1540 includes an eleventh terminal, a twelfth terminal, a sixteenth inductor, an eleventh capacitor, and a twelfth capacitor. The first terminal of the eleventh capacitor and the first terminal of the sixteenth inductor are connected to the eleventh terminal. The second terminal of the eleventh capacitor and the second terminal of the sixteenth inductor are connected to the first terminal of the twelfth capacitor. The second terminal of the twelfth capacitor is connected to the twelfth terminal. One of the eleventh and twelfth terminals is connected to the output terminal of the second resonator 1510, and the other is connected to the third port 1300. In the second filter 1500, the second resonator 1510 and the sixth resonator 1540, which are connected in series, adopt the same topology, which makes it easier to control the admittance of the second filter 1500 and is beneficial to the mass production of the second filter 1500.

[0339] Since one of the ninth and tenth terminals is connected to the output of the first resonator 1410 and the other is grounded, the fifth resonator 1530 and the second resonator 1510 can be connected in parallel, which helps to reduce the insertion loss of the second filter 1500 when transmitting radio frequency signals. The fifth resonator 1530 is composed of three reactive elements (the thirteenth inductor, the ninth capacitor, and the tenth capacitor), and the sixth resonator 1540 is composed of three reactive elements (the sixteenth inductor, the eleventh capacitor, and the twelfth capacitor). The fifth resonator 1530 and the sixth resonator 1540 have fewer reactive elements, which helps to reduce the insertion loss of the multiplexer 1000.

[0340] Referring to Figure 49, the first resonator 1410, the third resonator 1420, and the fourth resonator 1430 each provide a zero point for the first filter 1400. The first filter 1400 has three zero points. In Figure 49, S11 is a graph showing the energy parameter variation of the RF signal input from the first port 1100 and reflected from the first port 1100. S21 in Figure 49 shows the energy parameter variation of the RF signal input from the first port 1100 and output from the second port 1200. S31 in Figure 49 shows the energy parameter variation of the RF signal input from the first port 1100 and output from the third port 1300. S21 in Figure 49 has three troughs. As the frequency of the RF signal changes, each trough of S21 can represent a zero point of the first filter 1400. The second filter 1500 has four zeros, and S31 in Figure 49 has four troughs. The second resonator 1510, the fifth resonator 1530 and the sixth resonator 1540 each provide a zero for the second filter 1500. The topology of the first filter 1400 forms a resonant cavity, which can provide an additional zero for the second filter 1500.

[0341] Please refer to Figures 50, 51, and 52. The first filter 1400 also includes a seventh resonator 1440. The input terminal of the seventh resonator 1440 is connected between the fourth resonator 1430 and the second port 1200, and the output terminal of the seventh resonator 1440 is grounded. Adding a seventh resonator 1440 to the first filter 1400 increases the number of zeros in the first filter 1400, thereby improving the filtering performance of the first filter 1400.

[0342] Please refer to Figure 53. The seventh resonator 1440 includes a thirteenth terminal 1441, a fourteenth terminal 1442, a thirteenth capacitor 1443, a fourteenth capacitor 1444, a nineteenth inductor 1445, and a twentieth inductor 1446. The first end of the nineteenth inductor 1445 is connected to the thirteenth terminal 1441. The second end of the nineteenth inductor 1445 is connected to the first ends of the thirteenth capacitor 1443 and the twentieth inductor 1446. The second end of the twentieth inductor 1446 is connected to the first end of the fourteenth capacitor 1444. The second ends of the thirteenth capacitor 1443 and the fourteenth capacitor 1444 are both connected to the fourteenth terminal 1442. One of the thirteenth terminal 1441 and the fourteenth terminal 1442 is connected between the output terminal and the second port 1200 of the fourth resonator 1430, and the other is grounded.

[0343] The capacitance of the thirteenth capacitor 1443 and the fourteenth capacitor 1444 both do not exceed 10pF. The capacitance of the thirteenth capacitor 1443 and the fourteenth capacitor 1444 can be between 0.01pF and 10pF. The capacitance of the thirteenth capacitor 1443 can be 0.01pF, and the capacitance of the fourteenth capacitor 1444 can be 10pF. The capacitance of the fourteenth capacitor 1444 can be any value from 0.01pF to 10pF (e.g., 5pF).

[0344] The seventh resonator 1440 has a nineteenth inductor 1445 and a twentieth inductor 1446, which can provide two zeros for the first filter 1400. The inductance values ​​of the nineteenth inductor 1445 and the twentieth inductor 1446 do not exceed 10nH, and the inductance values ​​of the nineteenth inductor 1445 and the twentieth inductor 1446 can be between 0.01nH and 10nH. The inductance value of the nineteenth inductor 1445 can be 0.01nH, the inductance value of the nineteenth inductor 1445 can be 10nH, and the inductance value of the nineteenth inductor 1445 can be any value from 0.01nH to 10nH (e.g., 5nH). The inductance value of the twentieth inductor 1446 can be 0.01nH, 10nH, or any value from 0.01nH to 10nH (e.g., 5nH).

[0345] Please refer to Figure 52. In Figure 52, S11 is a graph showing the energy parameter variation of the RF signal input from the first port 1100 and reflected from the first port 1100. In Figure 52, S21 is a graph showing the energy parameter variation of the RF signal input from the first port 1100 and output from the second port 1200. In Figure 52, S31 is a graph showing the energy parameter variation of the RF signal input from the first port 1100 and output from the third port 1300. The seventh resonator 1440 has a nineteenth inductor 1445 and a twentieth inductor 1446, which can add two zeros to the first filter 1400. In Figure 52, S21 has five troughs. As the frequency of the RF signal changes, each trough of S21 can represent a zero of the first filter 1400. The seventh resonator 1440 is connected in parallel with the first resonator 1410. Compared with the seventh resonator 1440 being connected in series with the first resonator 1410, this can reduce the insertion loss of the first filter 1400. It should be noted that the series inductors suppress high-frequency radio frequency signals, which increases the insertion loss of the first filter 1400. The seventh resonator 1440 has a nineteenth inductor 1445 and a twentieth inductor 1446, which can provide two zeros for the first filter 1400.

[0346] In the seventh resonator, in, The impedance of the nineteenth inductor is used to characterize the complex frequency of the first filter, ω1 is used to characterize the angular frequency of the first filter, and L... 19 The inductance value used to characterize the nineteenth inductor. The impedance L used to characterize the twentieth inductor 20 The inductance value used to characterize the twentieth inductor. C is used to characterize the impedance of the thirteenth capacitor. 13 The capacitance value used to characterize the thirteenth capacitor. The impedance of the fourteenth capacitor, C 14 The capacitance value used to characterize the fourteenth capacitor.

[0347] Used to characterize the impedance of the twentieth inductor connected in series with the fourteenth capacitor;

[0348] It is used to characterize the impedance of the twentieth inductor and the fourteenth capacitor connected in series, and then connected in parallel with the thirteenth capacitor.

[0349] Z7 is used to characterize the impedance of the seventh resonator. When the impedance of the seventh resonator is zero, the seventh resonator short-circuits the first filter. The seventh resonator can effectively suppress the transmission of radio frequency signals from the first port to the second port.

[0350] Among them, S14 L 19 L 20 C 13 C 14 +S1 2 (L 20 C 14 +L 19 C 14 +L 19 C 14 )+1=0.

[0351] Since S1 = jω1, and ω1 has two positive solutions, the seventh resonator can provide two zeros for the first filter.

[0352] The seventh resonator can provide poles for the first filter, S1 3 L 20 C 13 C 14 +S1(C 13 +C 14 )=0,S1=jω1.

[0353] In some embodiments, referring to FIG51, the first filter 1400 includes a first port 1100, a second port 1200, a first resonator 1410, a third resonator 1420, a fourth resonator 1430, and a seventh resonator 1440. The input terminal of the first resonator 1410 is connected to the first port 1100. The fourth resonator 1430 is connected in series between the first resonator 1410 and the second port 1200. The input terminal of the third resonator 1420 is connected between the first resonator 1410 and the fourth resonator 1430. The output terminal of the third resonator 1420 is grounded. The input terminal of the seventh resonator 1440 is connected between the fourth resonator 1430 and the second port 1200. The output terminal of the seventh resonator 1440 is grounded. The second filter 1500 includes a second resonator 1510, a fifth resonator 1530, and a sixth resonator 1540. The input terminal of the second resonator 1510 is connected to the first port 1100. The sixth resonator 1540 is connected in series between the second resonator 1510 and the third port 1300. The input terminal of the fifth resonator 1530 is connected between the output terminal of the second resonator 1510 and the input terminal of the sixth resonator 1540. The output terminal of the fifth resonator 1530 is grounded. The fifth resonator 1530 includes a ninth terminal, a tenth terminal, a ninth capacitor, a tenth capacitor, a thirteenth inductor, and a fourteenth inductor; the first terminal of the thirteenth inductor is connected to the ninth terminal, the second terminal of the thirteenth inductor is connected to the first terminal of the ninth capacitor and the first terminal of the fourteenth inductor, the second terminal of the fourteenth inductor is connected to the first terminal of the tenth capacitor, and the second terminals of the ninth and tenth capacitors are connected to the tenth terminal; one of the ninth and tenth terminals is connected to the output terminal of the second resonator 1510, and the other is grounded; the sixth resonator 1540 includes an eleventh terminal, a twelfth terminal, a sixteenth inductor, an eleventh capacitor, and a twelfth capacitor, the first terminal of the eleventh capacitor and the first terminal of the sixteenth inductor are connected to the eleventh terminal, the second terminal of the eleventh capacitor and the second terminal of the sixteenth inductor are connected to the first terminal of the twelfth capacitor, the second terminal of the twelfth capacitor is connected to the twelfth terminal, one of the eleventh and twelfth terminals is connected to the output terminal of the second resonator 1510, and the other is connected to the third port 1300. In the second filter 1500, the second resonator 1510 and the sixth resonator 1540, which are connected in series, adopt the same topology. This makes it easier to control the admittance of the second filter 1500 and is beneficial to the mass production of the second filter 1500. Since one of the ninth and tenth terminals is connected to the output terminal of the first resonator 1410 and the other is grounded, the fifth resonator 1530 can be connected in parallel with the second resonator 1510, which helps to reduce the insertion loss of the second filter 1500 when transmitting radio frequency signals.The fifth resonator 1530 is composed of four reactive elements (such as the thirteenth inductor, the fourteenth inductor, the ninth capacitor, and the tenth capacitor), and the fifth resonator 1530 can provide two zeros for the second filter 1500.

[0354] The principle by which the fifth resonator provides two zeros for the second filter is the same as the principle by which the seventh filter provides two zeros for the first filter.

[0355] Z5 is used to characterize the impedance of the fifth resonator, L 13 The inductance value L is used to characterize the thirteenth inductor. 14 C9 is used to characterize the inductance value of the fourteenth inductor, and C9 is used to characterize the capacitance value of the ninth capacitor. 10 S2 is used to characterize the capacitance value of the tenth capacitor, and S2 is used to characterize the complex frequency of the fifth resonator. S2 = jω2, where ω2 is used to characterize the angular frequency of the fifth resonator, and j is used to characterize the imaginary number.

[0356] When the impedance of the fifth resonator is zero, the fifth resonator short-circuits the second filter, effectively suppressing the transmission of radio frequency signals from the first port to the third port. At this time, S2 4 L 13 L 14 C9C 10 +S2 2 (L 13 C 10 +L 13 C 10 +L 13 C 10 )+1=0.

[0357] ω2 has two positive solutions, and the fifth resonator can provide two zeros for the second filter.

[0358] When the impedance of the fifth resonator is infinite (the admittance of the fifth resonator is zero), the fifth resonator can provide a pole for the second filter, S. 3 L 14 C9C 10 +S(C9+C 10 )=0,S=jω2.

[0359] The second resonator 1510 provides a zero point for the second filter 1500, and the sixth resonator 1540 provides a zero point for the second filter 1500. The topology of the first filter 1400 can form a resonant cavity, and the first filter 1400 can provide a zero point for the second filter 1500. The second filter 1500 has five zero points, as shown in Figure 52, where S31 has five troughs. The fifth resonator 1530 is connected in parallel with the first resonator 1410. Compared to connecting the fifth resonator 1530 and the first resonator 1410 in series, this reduces the insertion loss of the second filter 1500. It should be noted that the series inductor suppresses high-frequency radio frequency signals, which increases the insertion loss of the second filter 1500.

[0360] In the embodiments provided in this application, the multiplexer may further include a third filter and a fourth port, with the third filter connected in series between the first port and the fourth port. The multiplexer may also include a fourth filter and a fifth port, with the fourth filter connected in series between the first port and the fifth port. The multiplexer may also include more filters and more ports, with the filters connected in parallel. This application does not limit the specific number of filters and ports.

[0361] It should be understood that expressions such as “comprising” and “may include” used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as “comprising” and / or “having” are to be interpreted as indicating a particular characteristic, number, operation, constituent element, component, or combination thereof, but not to exclude the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0362] Furthermore, in this application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0363] In this application, expressions including ordinal numbers such as "first" and "second" may modify the elements. However, such elements are not limited by the foregoing expressions. For example, the foregoing expressions do not limit the order and / or importance of the elements. The foregoing expressions are only used to distinguish one element from other elements. For example, "first user equipment" and "second user equipment" refer to different user equipment, although both "first user equipment" and "second user equipment" are user equipment. Similarly, without departing from the scope of this application, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0364] When a component is referred to as "connected" or "accessed" to other components, it should be understood that this component not only connects directly to or accesses other components, but also that another component may exist between this component and other components. On the other hand, when a component is referred to as "directly connected" or "directly accessed" to other components, it should be understood that no component exists between them.

[0365] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A multiplexer, characterized in that, Includes a first port, a first filter, a second filter, a second port, and a third port; The first filter is used for filtering a first frequency band. The first filter includes a first resonator, which is connected in series between a first port and a second port, and the input terminal of the first resonator is connected to the first port. The second filter is used for filtering a second frequency band, which is different from the first frequency band. The second filter includes a second resonator connected in series between the first port and the third port, and the input terminal of the second resonator is connected to the first port.

2. The multiplexer as described in claim 1, characterized in that, The admittances of the first resonator and the second resonator are complementary.

3. The multiplexer as described in claim 1 or 2, characterized in that, The first resonator includes one of the following structures: The first resonator includes a first terminal, a second terminal, a first inductor, a first capacitor, and a second capacitor. The first terminal of the first capacitor and the first terminal of the first inductor are connected to the first terminal. The second terminal of the first capacitor and the second terminal of the first inductor are connected to the first terminal. The second terminal of the second capacitor is connected to the second terminal. One of the first terminal and the second terminal is connected to the first port, and the other is connected to the second port. The first resonator includes a first terminal, a second terminal, a first inductor, a first capacitor, and a second capacitor. The first terminal of the first capacitor and the first terminal of the first inductor are connected to the first terminal. The second terminal of the first inductor is connected to the first terminal. The second terminal of the first capacitor and the second terminal of the second capacitor are connected to the second terminal. One of the first terminals is connected to the first port, and the other terminal is connected to the second port. The first resonator includes a first terminal, a second terminal, a first capacitor, a second capacitor, a first inductor, and a second inductor; the first terminal of the first capacitor and the first terminal of the first inductor are both connected to the first terminal, the second terminal of the first capacitor and the second terminal of the first inductor are both connected to the first terminal of the second capacitor, the second terminal of the second capacitor is connected to the first terminal of the second inductor, the second terminal of the second inductor is connected to the second terminal, one of the first terminal and the second terminal is connected to the first port, and the other terminal is connected to the second port; The first resonator includes a first terminal, a second terminal, a first capacitor, a second capacitor, a first inductor, and a second inductor; the first terminal of the first inductor is connected to the first terminal, the second terminal of the first inductor is connected to the first terminal of the first capacitor and the first terminal of the second inductor, the second terminal of the first capacitor and the second terminal of the second inductor are both connected to the first terminal of the second capacitor, the second terminal of the second capacitor is connected to the second terminal, one of the first terminal and the second terminal is connected to the first port, and the other terminal is connected to the second port; The first resonator includes a first terminal, a second terminal, a first capacitor, a second capacitor, a first inductor, and a second inductor. The first terminal of the first inductor is connected to the first terminal, the second terminal of the first inductor is connected to the first terminal of the first capacitor and the first terminal of the second inductor, the second terminal of the second inductor is connected to the first terminal of the second capacitor, the second terminals of the first capacitor and the second terminal are both connected to the second terminal, and one of the first terminal and the second terminal is connected to the first port, and the other terminal is connected to the second port. The first resonator includes a first terminal, a second terminal, a first capacitor, a second capacitor, a first inductor, a second inductor, and a third inductor; the first terminal of the first inductor is connected to the first terminal, the second terminal of the first inductor is connected to the first terminal of the first capacitor and the first terminal of the second inductor, the second terminal of the second inductor is connected to the first terminal of the second capacitor, the second terminal of the second capacitor and the second terminal of the first capacitor are both connected to the first terminal of the third inductor, the second terminal of the third inductor is connected to the second terminal, one of the first terminal and the second terminal is connected to the first port, and the other is connected to the second port; The first resonator includes a first terminal, a second terminal, a first capacitor, a second capacitor, a first inductor, a second inductor, and a third inductor; the first terminal of the first inductor is connected to the first terminal, the second terminal of the first inductor is connected to the first terminal of the first capacitor and the first terminal of the second inductor, the second terminal of the first capacitor and the second terminal of the second inductor are jointly connected to the first terminal of the second capacitor, the second terminal of the second capacitor is connected to the first terminal of the third inductor, the second terminal of the third inductor is connected to the second terminal, one of the first terminal and the second terminal is connected to the first port, and the other terminal is connected to the second port.

4. The multiplexer as described in any one of claims 1-3, characterized in that, The second resonator includes one of the following structures: The second resonator includes a third terminal, a fourth terminal, a fourth inductor, a third capacitor, and a fourth capacitor. The first terminal of the third capacitor and the first terminal of the fourth inductor are connected to the third terminal. The second terminal of the third capacitor and the second terminal of the fourth inductor are connected to the first terminal of the fourth capacitor. The second terminal of the fourth capacitor is connected to the fourth terminal. One of the third terminal and the fourth terminal is connected to the first port, and the other is connected to the third port. The second resonator includes a third terminal, a fourth terminal, a fourth inductor, a third capacitor, and a fourth capacitor. The first terminal of the third capacitor and the first terminal of the fourth inductor are connected to the third terminal. The second terminal of the fourth inductor is connected to the first terminal of the fourth capacitor. The second terminal of the third capacitor and the second terminal of the fourth capacitor are connected to the fourth terminal. One of the third terminal and the fourth terminal is connected to the first port, and the other is connected to the third port. The second resonator includes a third terminal, a fourth terminal, a third capacitor, a fourth capacitor, a fourth inductor, and a fifth inductor; the first terminal of the third capacitor and the first terminal of the fourth inductor are both connected to the third terminal, the second terminal of the third capacitor and the second terminal of the fourth inductor are both connected to the first terminal of the fourth capacitor, the second terminal of the fourth capacitor is connected to the first terminal of the fifth inductor, the second terminal of the fifth inductor is connected to the fourth terminal, one of the third terminal and the fourth terminal is connected to the first port, and the other is connected to the third port; The second resonator includes a third terminal, a fourth terminal, a third capacitor, a fourth capacitor, a fourth inductor, and a fifth inductor; the first terminal of the fourth inductor is connected to the third terminal, the second terminal of the fourth inductor is connected to the first terminal of the third capacitor and the first terminal of the fifth inductor, the second terminal of the third capacitor and the second terminal of the fifth inductor are both connected to the first terminal of the fourth capacitor, the second terminal of the fourth capacitor is connected to the fourth terminal, one of the third terminal and the fourth terminal is connected to the first port, and the other is connected to the third port; The second resonator includes a third terminal, a fourth terminal, a third capacitor, a fourth capacitor, a fourth inductor, and a fifth inductor. The first terminal of the fourth inductor is connected to the third terminal, the second terminal of the fourth inductor is connected to the first terminal of the third capacitor and the first terminal of the fifth inductor, the second terminal of the fifth inductor is connected to the first terminal of the fourth capacitor, the second terminals of the third capacitor and the second terminals of the fourth capacitor are both connected to the fourth terminal, one of the third terminal and the fourth terminal is connected to the first port, and the other is connected to the third port. The second resonator includes a third terminal, a fourth terminal, a third capacitor, a fourth capacitor, a fourth inductor, a fifth inductor, and a sixth inductor; the first terminal of the fourth inductor is connected to the third terminal, the second terminal of the fourth inductor is connected to the first terminal of the third capacitor and the first terminal of the fifth inductor, the second terminal of the fifth inductor is connected to the first terminal of the fourth capacitor, the second terminal of the fourth capacitor and the second terminal of the third capacitor are both connected to the first terminal of the sixth inductor, the second terminal of the sixth inductor is connected to the fourth terminal, one of the third terminal and the fourth terminal is connected to the first port, and the other is connected to the third port; The second resonator includes a third terminal, a fourth terminal, a third capacitor, a fourth capacitor, a fourth inductor, a fifth inductor, and a sixth inductor; the first terminal of the fourth inductor is connected to the third terminal, the second terminal of the fourth inductor is connected to the first terminal of the third capacitor and the first terminal of the fifth inductor, the second terminals of the third capacitor and the fifth inductor are jointly connected to the first terminal of the fourth capacitor, the second terminal of the fourth capacitor is connected to the first terminal of the sixth inductor, the second terminal of the sixth inductor is connected to the fourth terminal, one of the third terminal and the fourth terminal is connected to the first port, and the other is connected to the third port.

5. The multiplexer according to any one of claims 1-4, characterized in that, The first resonator includes a first terminal, a second terminal, a first inductor, a first capacitor, and a second capacitor. The first terminal of the first capacitor and the first terminal of the first inductor are connected to the first terminal. The second terminal of the first capacitor and the second terminal of the first inductor are connected to the first terminal. The second terminal of the second capacitor is connected to the second terminal. One of the first terminal and the second terminal is connected to the first port, and the other is connected to the second port. The second resonator includes a third terminal, a fourth terminal, a fourth inductor, a third capacitor, and a fourth capacitor. The first terminal of the third capacitor and the first terminal of the fourth inductor are connected to the third terminal. The second terminal of the third capacitor and the second terminal of the fourth inductor are connected to the first terminal of the fourth capacitor. The second terminal of the fourth capacitor is connected to the fourth terminal. One of the third terminal and the fourth terminal is connected to the first port, and the other is connected to the third port.

6. The multiplexer according to any one of claims 1-5, characterized in that, The first filter further includes a third resonator and a fourth resonator. The fourth resonator is connected in series between the first resonator and the second port. The input terminal of the third resonator is connected between the first resonator and the fourth resonator. The output terminal of the third resonator is grounded.

7. The multiplexer according to any one of claims 1-5, characterized in that, The first filter further includes a third resonator and a fourth resonator. The input terminal of the third resonator is connected to the output terminal of the first resonator, the output terminal of the third resonator is connected to the input terminal of the fourth resonator, and the output terminal of the fourth resonator is connected to the second port.

8. The multiplexer according to any one of claims 1-5, characterized in that, The first filter further includes a third resonator and a fourth resonator. The input terminal of the third resonator is connected to the output terminal of the first resonator. The output terminal of the third resonator and the input terminal of the fourth resonator are both connected to the second port. The output terminal of the fourth resonator is grounded.

9. The multiplexer according to any one of claims 6-8, characterized in that, The third resonator includes one of the following structures: The third resonator includes a fifth terminal, a sixth terminal, a seventh inductor, a fifth capacitor, and a sixth capacitor. The first terminal of the fifth capacitor and the first terminal of the seventh inductor are both connected to the fifth terminal. The second terminal of the fifth capacitor and the second terminal of the seventh inductor are both connected to the first terminal of the sixth capacitor. The second terminal of the sixth capacitor is connected to the sixth terminal. One of the fifth terminal and the sixth terminal is the input terminal of the third resonator, and the other is the output terminal of the third resonator. The third resonator includes a fifth terminal, a sixth terminal, a seventh inductor, a fifth capacitor, and a sixth capacitor. The first terminal of the fifth capacitor and the first terminal of the seventh inductor are both connected to the third terminal. The second terminal of the seventh inductor is connected to the first terminal of the sixth capacitor. The second terminal of the fifth capacitor and the second terminal of the sixth capacitor are both connected to the sixth terminal. One of the fifth terminal and the sixth terminal is the input terminal of the third resonator, and the other is the output terminal of the third resonator. The third resonator includes a fifth terminal, a sixth terminal, a fifth capacitor, a sixth capacitor, a seventh inductor, and an eighth inductor; the first terminals of the fifth capacitor and the seventh inductor are connected to the fifth terminal, the second terminals of the fifth capacitor and the seventh inductor are connected to the first terminal of the sixth capacitor, the second terminal of the sixth capacitor is connected to the first terminal of the eighth inductor, and the second terminal of the eighth inductor is connected to the sixth terminal; one of the fifth terminal and the sixth terminal is the input terminal of the third resonator, and the other is the output terminal of the third resonator. The third resonator includes a fifth terminal, a sixth terminal, a fifth capacitor, a sixth capacitor, a seventh inductor, and an eighth inductor; the first terminal of the seventh inductor is connected to the fifth terminal, the second terminal of the seventh inductor is connected to the first terminal of the fifth capacitor and the first terminal of the eighth inductor, the second terminals of the fifth capacitor and the eighth inductor are jointly connected to the first terminal of the sixth capacitor, and the second terminal of the sixth capacitor is connected to the sixth terminal; one of the fifth terminal and the sixth terminal is the input terminal of the third resonator, and the other is the output terminal of the third resonator; The third resonator includes a fifth terminal, a sixth terminal, a fifth capacitor, a sixth capacitor, a seventh inductor, and an eighth inductor. The first terminal of the seventh inductor is connected to the fifth terminal, the second terminal of the seventh inductor is connected to the first terminals of the fifth and eighth capacitors, the second terminal of the eighth inductor is connected to the first terminal of the sixth capacitor, and the second terminals of the fifth and sixth capacitors are both connected to the sixth terminal. One of the fifth and sixth terminals is the input terminal of the third resonator, and the other is the output terminal of the third resonator. The third resonator includes a fifth terminal, a sixth terminal, a fifth capacitor, a sixth capacitor, a seventh inductor, an eighth inductor, and a ninth inductor; the first terminal of the seventh inductor is connected to the fifth terminal, the second terminal of the seventh inductor is connected to the first terminal of the fifth capacitor and the first terminal of the eighth inductor, the second terminal of the eighth inductor is connected to the first terminal of the sixth capacitor, the second terminal of the sixth capacitor and the second terminal of the fifth capacitor are jointly connected to the first terminal of the ninth inductor, and the second terminal of the ninth inductor is connected to the sixth terminal. The third resonator includes a fifth terminal, a sixth terminal, a fifth capacitor, a sixth capacitor, a seventh inductor, an eighth inductor, and a ninth inductor; the first terminal of the seventh inductor is connected to the fifth terminal, the second terminal of the seventh inductor is connected to the first terminal of the fifth capacitor and the first terminal of the eighth inductor, the second terminals of the fifth capacitor and the eighth inductor are jointly connected to the first terminal of the sixth capacitor, the second terminal of the sixth capacitor is connected to the first terminal of the ninth inductor, and the second terminal of the ninth inductor is connected to the sixth terminal. One of the fifth terminal and the sixth terminal is the input terminal of the third resonator, and the other is the output terminal of the third resonator.

10. The multiplexer according to any one of claims 6-8, characterized in that, The fourth resonator includes one of the following structures: The fourth resonator includes a seventh terminal, an eighth terminal, a tenth inductor, a seventh capacitor, and an eighth capacitor. The first terminal of the seventh capacitor and the first terminal of the tenth inductor are both connected to the seventh terminal. The second terminal of the seventh capacitor and the second terminal of the tenth inductor are both connected to the first terminal of the eighth capacitor. The second terminal of the eighth capacitor is connected to the eighth terminal. One of the seventh terminal and the eighth terminal is the input terminal of the fourth resonator, and the other is the output terminal of the fourth resonator. The fourth resonator includes a seventh terminal, an eighth terminal, a tenth inductor, a seventh capacitor, and an eighth capacitor. The first terminal of the seventh capacitor and the first terminal of the tenth inductor are both connected to the seventh terminal. The second terminal of the tenth inductor is connected to the first terminal of the eighth capacitor. The second terminals of the seventh capacitor and the second terminals of the eighth capacitor are both connected to the eighth terminal. One of the seventh terminal and the eighth terminal is the input terminal of the fourth resonator, and the other is the output terminal of the fourth resonator. The fourth resonator includes a seventh terminal, an eighth terminal, a seventh capacitor, an eighth capacitor, a tenth inductor, and an eleventh inductor; the first terminal of the seventh capacitor and the first terminal of the tenth inductor are both connected to the seventh terminal, the second terminal of the seventh capacitor and the second terminal of the tenth inductor are both connected to the first terminal of the eighth capacitor, the second terminal of the eighth capacitor is connected to the first terminal of the eleventh inductor, and the second terminal of the eleventh inductor is connected to the eighth terminal; one of the seventh terminal and the eighth terminal is the input terminal of the fourth resonator, and the other is the output terminal of the fourth resonator; The fourth resonator includes a seventh terminal, an eighth terminal, a seventh capacitor, an eighth capacitor, a tenth inductor, and an eleventh inductor; the first terminal of the tenth inductor is connected to the seventh terminal, the second terminal of the tenth inductor is connected to the first terminals of the seventh and eleventh inductors, the second terminals of the seventh and eleventh inductors are jointly connected to the first terminal of the eighth capacitor, and the second terminal of the eighth capacitor is connected to the eighth terminal; one of the seventh and eighth terminals is the input terminal of the fourth resonator, and the other is the output terminal of the fourth resonator. The fourth resonator includes a seventh terminal, an eighth terminal, a seventh capacitor, an eighth capacitor, a tenth inductor, and an eleventh inductor; the first terminal of the tenth inductor is connected to the seventh terminal, the second terminal of the tenth inductor is connected to the first terminals of the seventh and eleventh inductors, the second terminal of the eleventh inductor is connected to the first terminal of the eighth capacitor, and the second terminals of the seventh and eighth capacitors are jointly connected to the eighth terminal; one of the seventh and eighth terminals is the input terminal of the fourth resonator, and the other is the output terminal of the fourth resonator. The fourth resonator includes a seventh terminal, an eighth terminal, a seventh capacitor, an eighth capacitor, a tenth inductor, an eleventh inductor, and a twelfth inductor; the first terminal of the tenth inductor is connected to the seventh terminal, the second terminal of the tenth inductor is connected to the first terminals of the seventh and eleventh capacitors, the second terminal of the eleventh inductor is connected to the first terminal of the eighth capacitor, the second terminal of the eighth capacitor and the second terminal of the seventh capacitor are jointly connected to the first terminal of the twelfth inductor, and the second terminal of the twelfth inductor is connected to the eighth terminal; one of the seventh terminal and the eighth terminal is the input terminal of the fourth resonator, and the other is the output terminal of the fourth resonator; The fourth resonator includes a seventh terminal, an eighth terminal, a seventh capacitor, an eighth capacitor, a tenth inductor, an eleventh inductor, and a twelfth inductor. The first terminal of the tenth inductor is connected to the seventh terminal, the second terminal of the tenth inductor is connected to the first terminals of the seventh and eleventh capacitors, the second terminals of the seventh and eleventh inductors are jointly connected to the first terminal of the eighth capacitor, the second terminal of the eighth capacitor is connected to the first terminal of the twelfth inductor, and the second terminal of the twelfth inductor is connected to the eighth terminal. One of the seventh and eighth terminal terminals is the input terminal of the fourth resonator, and the other is the output terminal of the fourth resonator.

11. The multiplexer according to any one of claims 6-8, characterized in that, The third resonator includes a fifth terminal, a sixth terminal, a seventh inductor, a fifth capacitor, and a sixth capacitor. The first terminal of the fifth capacitor and the first terminal of the seventh inductor are connected to the fifth terminal. The second terminal of the fifth capacitor and the second terminal of the seventh inductor are connected to the first terminal of the sixth capacitor. The second terminal of the sixth capacitor is connected to the sixth terminal. One of the fifth and sixth endpoints is connected to the output of the first resonator, and the other is grounded; The fourth resonator includes a seventh terminal, an eighth terminal, a tenth inductor, a seventh capacitor, and an eighth capacitor. The first terminal of the seventh capacitor and the first terminal of the tenth inductor are connected to the seventh terminal. The second terminal of the seventh capacitor and the second terminal of the tenth inductor are connected to the first terminal of the eighth capacitor. The second terminal of the eighth capacitor is connected to the eighth terminal. One of the seventh terminal and the eighth terminal is connected to the output terminal of the first resonator, and the other is connected to the second port.

12. The multiplexer according to any one of claims 1-11, characterized in that, The second filter further includes a fifth resonator and a sixth resonator. The sixth resonator is connected in series between the second resonator and the third port. The input terminal of the fifth resonator is connected between the second resonator and the sixth resonator. The output terminal of the fifth resonator is grounded.

13. The multiplexer according to any one of claims 1-12, characterized in that, The second filter further includes a fifth resonator and a sixth resonator. The input terminal of the fifth resonator is connected to the output terminal of the second resonator, the output terminal of the fifth resonator is connected to the input terminal of the sixth resonator, and the output terminal of the sixth resonator is connected to the third port.

14. The multiplexer according to any one of claims 1-12, characterized in that, The second filter further includes a fifth resonator and a sixth resonator. The input terminal of the fifth resonator is connected to the output terminal of the second resonator. The output terminal of the fifth resonator and the input terminal of the sixth resonator are both connected to the third port. The output terminal of the sixth resonator is grounded.

15. The multiplexer according to any one of claims 12-14, characterized in that, The fifth resonator includes one of the following structures: The fifth resonator includes a ninth terminal, a tenth terminal, a thirteenth inductor, a ninth capacitor, and a tenth capacitor. The first terminal of the ninth capacitor and the first terminal of the thirteenth inductor are both connected to the ninth terminal. The second terminal of the ninth capacitor and the second terminal of the thirteenth inductor are both connected to the first terminal of the tenth capacitor. The second terminal of the tenth capacitor is connected to the tenth terminal. One of the ninth terminal and the tenth terminal is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator. The fifth resonator includes a ninth terminal, a tenth terminal, a thirteenth inductor, a ninth capacitor, and a tenth capacitor. The first terminal of the ninth capacitor and the first terminal of the thirteenth inductor are connected to the ninth terminal. The second terminal of the thirteenth inductor is connected to the first terminal of the tenth capacitor. The second terminal of the ninth capacitor and the second terminal of the tenth capacitor are connected to the tenth terminal. One of the ninth and tenth endpoints is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator; The fifth resonator includes a ninth terminal, a tenth terminal, a ninth capacitor, a tenth capacitor, a thirteenth inductor, and a fourteenth inductor; the first terminal of the ninth capacitor and the first terminal of the thirteenth inductor are connected to the ninth terminal, the second terminal of the ninth capacitor and the second terminal of the thirteenth inductor are connected to the first terminal of the ninth capacitor, the second terminal of the tenth capacitor is connected to the first terminal of the fourteenth inductor, and the second terminal of the fourteenth inductor is connected to the tenth terminal. One of the ninth and tenth endpoints is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator; The fifth resonator includes a ninth terminal, a tenth terminal, a ninth capacitor, a tenth capacitor, a thirteenth inductor, and a fourteenth inductor; the first terminal of the thirteenth inductor is connected to the ninth terminal, the second terminal of the thirteenth inductor is connected to the first terminal of the ninth capacitor and the first terminal of the fourteenth inductor, the second terminals of the ninth capacitor and the fourteenth inductor are jointly connected to the first terminal of the tenth capacitor, and the second terminal of the tenth capacitor is connected to the tenth terminal. One of the ninth and tenth endpoints is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator; The fifth resonator includes a ninth terminal, a tenth terminal, a ninth capacitor, a tenth capacitor, a thirteenth inductor, and a fourteenth inductor; the first terminal of the thirteenth inductor is connected to the ninth terminal, the second terminal of the thirteenth inductor is connected to the first terminal of the ninth capacitor and the first terminal of the fourteenth inductor, the second terminal of the fourteenth inductor is connected to the first terminal of the tenth capacitor, and the second terminals of the ninth capacitor and the tenth capacitor are both connected to the tenth terminal. One of the ninth and tenth endpoints is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator; The fifth resonator includes a ninth terminal, a tenth terminal, a ninth capacitor, a tenth capacitor, a thirteenth inductor, a fourteenth inductor, and a fifteenth inductor; the first terminal of the thirteenth inductor is connected to the ninth terminal, the second terminal of the thirteenth inductor is connected to the first terminals of the ninth and fourteenth capacitors, the second terminal of the fourteenth inductor is connected to the first terminal of the tenth capacitor, the second terminal of the tenth capacitor and the second terminal of the ninth capacitor are jointly connected to the first terminal of the fifteenth inductor, and the second terminal of the fifteenth inductor is connected to the tenth terminal; one of the ninth and tenth terminals is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator. The fifth resonator includes a ninth terminal, a tenth terminal, a ninth capacitor, a tenth capacitor, a thirteenth inductor, a fourteenth inductor, and a fifteenth inductor. The first terminal of the thirteenth inductor is connected to the ninth terminal, the second terminal of the thirteenth inductor is connected to the first terminal of the ninth capacitor and the first terminal of the fourteenth inductor, the second terminals of the ninth capacitor and the fourteenth inductor are jointly connected to the first terminal of the tenth capacitor, the second terminal of the tenth capacitor is connected to the first terminal of the fifteenth inductor, and the second terminal of the fifteenth inductor is connected to the tenth terminal. One of the ninth terminal and the tenth terminal is the input terminal of the fifth resonator, and the other is the output terminal of the fifth resonator.

16. The multiplexer according to any one of claims 12-14, characterized in that, The sixth resonator includes one of the following structures: The sixth resonator includes an eleventh terminal, a twelfth terminal, a sixteenth inductor, an eleventh capacitor, and a twelfth capacitor. The first terminal of the eleventh capacitor and the first terminal of the sixteenth inductor are both connected to the eleventh terminal. The second terminal of the eleventh capacitor and the second terminal of the sixteenth inductor are both connected to the first terminal of the twelfth capacitor. The second terminal of the twelfth capacitor is connected to the twelfth terminal. One of the eleventh terminal and the twelfth terminal is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator. The sixth resonator includes an eleventh terminal, a twelfth terminal, a sixteenth inductor, an eleventh capacitor, and a twelfth capacitor. The first terminal of the eleventh capacitor and the first terminal of the sixteenth inductor are both connected to the eleventh terminal. The second terminal of the sixteenth inductor is connected to the first terminal of the twelfth capacitor. The second terminal of the eleventh capacitor and the second terminal of the twelfth capacitor are both connected to the twelfth terminal. One of the eleventh terminal and the twelfth terminal is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator. The sixth resonator includes an eleventh terminal, a twelfth terminal, an eleventh capacitor, a twelfth capacitor, a sixteenth inductor, and a seventeenth inductor; the first terminal of the eleventh capacitor and the first terminal of the sixteenth inductor are both connected to the eleventh terminal, the second terminal of the eleventh capacitor and the second terminal of the sixteenth inductor are both connected to the first terminal of the eleventh capacitor, the second terminal of the twelfth capacitor is connected to the first terminal of the seventeenth inductor, and the second terminal of the seventeenth inductor is connected to the twelfth terminal. One of the eleventh and twelfth endpoints is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator; The sixth resonator includes an eleventh terminal, a twelfth terminal, an eleventh capacitor, a twelfth capacitor, a sixteenth inductor, and a seventeenth inductor; the first terminal of the sixteenth inductor is connected to the eleventh terminal, the second terminal of the sixteenth inductor is connected to the first terminals of the eleventh and seventeenth inductors, the second terminals of the eleventh and seventeenth inductors are jointly connected to the first terminal of the twelfth capacitor, and the second terminal of the twelfth capacitor is connected to the twelfth terminal; one of the eleventh and twelfth terminals is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator. The sixth resonator includes an eleventh terminal, a twelfth terminal, an eleventh capacitor, a twelfth capacitor, a sixteenth inductor, and a seventeenth inductor; the first terminal of the sixteenth inductor is connected to the eleventh terminal, the second terminal of the sixteenth inductor is connected to the first terminals of the eleventh and seventeenth capacitors, the second terminal of the seventeenth inductor is connected to the first terminal of the twelfth capacitor, and the second terminals of the eleventh and twelfth capacitors are both connected to the twelfth terminal; one of the eleventh and twelfth terminals is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator. The sixth resonator includes an eleventh terminal, a twelfth terminal, an eleventh capacitor, a twelfth capacitor, a sixteenth inductor, a seventeenth inductor, and an eighteenth inductor; the first terminal of the sixteenth inductor is connected to the eleventh terminal, the second terminal of the sixteenth inductor is connected to the first terminals of the eleventh and seventeenth capacitors, the second terminal of the seventeenth inductor is connected to the first terminal of the twelfth capacitor, the second terminal of the twelfth capacitor and the second terminal of the eleventh capacitor are both connected to the first terminal of the eighteenth inductor, and the second terminal of the eighteenth inductor is connected to the twelfth terminal; one of the eleventh and twelfth terminals is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator; The sixth resonator includes an eleventh terminal, a twelfth terminal, an eleventh capacitor, a twelfth capacitor, a sixteenth inductor, a seventeenth inductor, and an eighteenth inductor. The first terminal of the sixteenth inductor is connected to the eleventh terminal, the second terminal of the sixteenth inductor is connected to the first terminals of the eleventh and seventeenth capacitors, the second terminals of the eleventh and seventeenth inductors are jointly connected to the first terminal of the twelfth capacitor, the second terminal of the twelfth capacitor is connected to the first terminal of the eighteenth inductor, and the second terminal of the eighteenth inductor is connected to the twelfth terminal. One of the eleventh and twelfth terminals is the input terminal of the sixth resonator, and the other is the output terminal of the sixth resonator.

17. The multiplexer according to any one of claims 12-14, characterized in that, The fifth resonator includes a ninth terminal, a tenth terminal, a thirteenth inductor, a ninth capacitor, and a tenth capacitor. The first terminal of the ninth capacitor and the first terminal of the thirteenth inductor are both connected to the ninth terminal. The second terminal of the ninth capacitor and the second terminal of the thirteenth inductor are both connected to the first terminal of the tenth capacitor. The second terminal of the tenth capacitor is connected to the tenth terminal. One of the ninth terminal and the tenth terminal is connected to the output terminal of the second resonator, and the other is grounded. The sixth resonator includes an eleventh terminal, a twelfth terminal, a sixteenth inductor, an eleventh capacitor, and a twelfth capacitor. The first terminal of the eleventh capacitor and the first terminal of the sixteenth inductor are connected to the eleventh terminal. The second terminal of the eleventh capacitor and the second terminal of the sixteenth inductor are connected to the first terminal of the twelfth capacitor. The second terminal of the twelfth capacitor is connected to the twelfth terminal. One of the eleventh terminal and the twelfth terminal is connected to the output terminal of the second resonator, and the other is connected to the third port.

18. The multiplexer according to any one of claims 6-8, characterized in that, The first filter further includes a seventh resonator, the input of which is connected between the fourth resonator and the second port, and the output of which is grounded.

19. The multiplexer as claimed in claim 18, characterized in that, The seventh resonator includes a thirteenth terminal, a fourteenth terminal, a thirteenth capacitor, a fourteenth capacitor, a nineteenth inductor, and a twentieth inductor. The first terminal of the nineteenth inductor is connected to the thirteenth terminal, and the second terminal of the nineteenth inductor is connected to the first terminal of the thirteenth capacitor and the first terminal of the twentieth inductor. The second terminal of the twentieth inductor is connected to the first terminal of the fourteenth capacitor. The second terminals of the thirteenth capacitor and the fourteenth capacitor are both connected to the fourteenth terminal. One of the thirteenth terminal and the fourteenth terminal is connected between the output terminal of the fourth resonator and the second port, and the other is grounded.

20. The multiplexer according to any one of claims 12-14, characterized in that, The fifth resonator includes a ninth terminal, a tenth terminal, a ninth capacitor, a tenth capacitor, a thirteenth inductor, and a fourteenth inductor; the first terminal of the thirteenth inductor is connected to the ninth terminal, the second terminal of the thirteenth inductor is connected to the first terminal of the ninth capacitor and the first terminal of the fourteenth inductor, the second terminal of the fourteenth inductor is connected to the first terminal of the tenth capacitor, and the second terminals of the ninth and tenth capacitors are both connected to the tenth terminal; one of the ninth and tenth terminals is connected to the output terminal of the second resonator, and the other is grounded; The sixth resonator includes an eleventh terminal, a twelfth terminal, a sixteenth inductor, an eleventh capacitor, and a twelfth capacitor. The first terminal of the eleventh capacitor and the first terminal of the sixteenth inductor are connected to the eleventh terminal. The second terminal of the eleventh capacitor and the second terminal of the sixteenth inductor are connected to the first terminal of the twelfth capacitor. The second terminal of the twelfth capacitor is connected to the twelfth terminal. One of the eleventh terminal and the twelfth terminal is connected to the output terminal of the second resonator, and the other is connected to the third port.

21. A radio frequency module, characterized in that, The radio frequency module includes a multiplexer as described in any one of claims 1-20.

22. A communication device, characterized in that, The communication device includes the multiplexer as described in claims 1-20 or the radio frequency module as described in claim 21.

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