Coupler and radio frequency front-end module

Abstract

The invention provides a coupler, a radio frequency module and communication equipment, which comprises an input port, an output port, a coupling port, an isolation port, a main line extending between the input port and the output port, and a coupling line extending between the coupling port and the isolation port, a first compensation capacitor is formed between the main line and the coupling line, and a second compensation capacitor is formed between the main line and the coupling line. According to the coupler, the directivity of the coupler can be ensured under a wide frequency band.

Description

Technical Field

[0001] The present invention relates to the field of radio frequency technology, and particularly to a coupler and a radio frequency front-end module. Background Art

[0002] A coupler is a device used to transfer high-frequency signals from one circuit to another. Its main function is to transfer the high-frequency signals in one circuit to another circuit while maintaining the stability and accuracy of the signals. The working principle of the coupler is based on the principle of electromagnetic induction, and it uses the interaction of electromagnetic fields to transfer signals. The main components of the coupler are two circuits, and they transfer signals through the interaction of electromagnetic fields. One of the circuits is called the "main circuit", and the other is called the "slave circuit". The high-frequency signals in the main circuit are transferred to the slave circuit through the action of the electromagnetic field, thus realizing the signal transfer. The working principle of the coupler includes: the high-frequency signals in the main circuit are transferred to the slave circuit through the action of the electromagnetic field. The high-frequency signals in the slave circuit are excited, thus generating a reverse electromagnetic field. The reverse electromagnetic field interacts with the high-frequency signals in the main circuit, thus generating a new electromagnetic field. The new electromagnetic field transfers the signal back to the main circuit, thus realizing the signal transfer. The function of the coupler is to transfer the high-frequency signals in one circuit to another circuit while maintaining the stability and accuracy of the signals. It can be used in many different applications, such as wireless communication, radar systems, medical devices, etc.

[0003] A coupler is an electronic device that can detect the power transmitted in a specific direction, and it is widely used in various radio frequency (RF) circuits. For example, a coupler can be used in a radar system to detect the reflected wave by separating the incident wave from the reflected wave, or in a circuit for measuring the impedance mismatch in a transmission line. However, existing couplers often have problems with poor directivity. Summary of the Invention

[0004] The object of the present invention is to provide a coupler that can ensure the directivity of the coupler in a wide frequency band.

[0005] The present application provides a coupler, including: an input port, an output port, a coupling port, and an isolation port, a main line extending between the input port and the output port, and a coupling line extending between the coupling port and the isolation port, and a first compensation capacitor is formed between the main line and the coupling line.

[0006] The present application further provides a coupler, comprising an input port; an output port; a coupling port; an isolation port; a main line, one end of the main line is connected to the input port, and the other end is connected to the output port; a coupling line, one end of the coupling line is connected to the coupling port, and the other end is connected to the isolation port; the main line and the coupling line overlap at least partially in the longitudinal direction to form the first compensation capacitor.

[0007] In this embodiment, the coupler includes: an input port, an output port, a coupling port and an isolation port, a main line extending between the input port and the output port, and a coupling line extending between the coupling port and the isolation port, a first compensation capacitor is formed between the main line and the coupling line; by forming the first compensation capacitor between the main line and the coupling line, since the first compensation capacitor can well improve the isolation and directivity of the coupler, the isolation and directivity of the coupler are improved in a wide frequency band.

[0008] In this embodiment, the coupler includes an input port; an output port; a coupling port; an isolation port; a main line, one end of the main line is connected to the input port, and the other end is connected to the output port; a coupling line, one end of the coupling line is connected to the coupling port, and the other end is connected to the isolation port; the main line and the coupling line overlap at least partially in the longitudinal direction to form the first compensation capacitor; by making the main line 10 and the coupling line 30 overlap at least partially in the longitudinal direction, the capacitance value of the first compensation capacitor can be flexibly adjusted, so as to improve the directivity and isolation of the coupler in a wide frequency band (especially at two frequency points with a large span, for example: [1.4 GHz, 2.69 GHz]) to meet the actual requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The drawings here are incorporated into the specification and form a part of this specification, showing the embodiments conforming to the present invention, and are used together with the specification to explain the principles of the present invention.

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0011] Figure 1 is a schematic structural diagram of the coupler of the present invention;

[0012] Figure 2 is another schematic structural diagram of the coupler of the present invention;

[0013] Figure 3 is another schematic structural diagram of the coupler of the present invention;

[0014] Figure 4 Another structural schematic diagram of the coupler of the present invention;

[0015] Figure 5 Another structural schematic diagram of the coupler of the present invention;

[0016] Figure 6 Another structural schematic diagram of the coupler of the present invention;

[0017] Figure 7 Another structural schematic diagram of the coupler of the present invention;

[0018] Figure 8 Another structural schematic diagram of the coupler of the present invention;

[0019] Figure 9 Another structural schematic diagram of the coupler of the present invention;

[0020] Figure 10 Another structural schematic diagram of the coupler of the present invention.

[0021] Coupler 100 Coupling line 30 Main line 10 Coupling port 3 Main coil 11 Isolation port 4 Input port 1 Third coupling section 31 Output port 2 Fourth coupling section 32 First part of the coupling line 20 Fifth coupling section 33 First extension 21 First coupling section 34 Second extension 42 Second coupling section 35 Third extension 23 Sixth coupling section 36 Fourth extension 44 Second part of the coupling line 40 Specific embodiments

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0023] It should be noted that all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If this specific posture changes, the directional indications will also change accordingly.

[0024] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0027] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0028] Existing couplers often have a directionality problem. The coupler of the present application includes an input port, an output port, a coupling port, and an isolation port, a main line extending between the input port and the output port, and a coupling line extending between the coupling port and the isolation port; a first compensation capacitor is formed between the main line and the coupling line. By adjusting the capacitance value of the first compensation capacitor, the odd-mode and even-mode impedances Z of the coupler at each frequency band can be adjusted. The odd-mode and even-mode impedances Z of the coupler are also associated with the coefficient K, and the coefficient K = 10 C / 10 , C is the coupling degree. Therefore, by adjusting the size of the first compensation capacitor, the directionality and isolation degree of the coupler in a wide frequency band (especially in the range of two frequency points with a large span, for example: [1.4 GHz, 2.69 GHz]) can be improved to meet the actual requirements.

[0029] Embodiment 1

[0030] The present application provides a coupler, as Figures 1 - 5 shown, including:

[0031] An input port 1, an output port 2, a coupling port 3, and an isolation port 4,

[0032] A main line 10 extending between the input port 1 and the output port 2, and a coupling line 30 extending between the coupling port 3 and the isolation port 4,

[0033] A first compensation capacitor is formed between the main line 10 and the coupling line 30.

[0034] Among them, directivity is a measure or quality factor of the ability of a coupler to distinguish incident waves and reflected waves in a transmission system. The quality of the directivity of a coupler depends on the electric field component and magnetic field component in the coupling circuit. When the components generated by these two sources are balanced, the directivity is optimal. The values of the electric field component and magnetic field component depend on the coupling capacitance and inductance on the coupling plate. The formula for calculating the directivity of a coupler is: D(dB) = ISO(dB) - C(dB), where D is the directivity of the coupler; ISO is the isolation of the coupler; C is the coupling degree of the coupler.

[0035] Among them, the impedance of a capacitor in an AC circuit is the capacitive reactance Xc, and the calculation formula is Xc = 1 / (ωC) = 1 / (2πfC), where f is the frequency, with the unit of Hz, ω = 2πf is the angular frequency, with the unit of 1 / s. In the RF circuit where the coupler is located, generally, the higher the frequency, the smaller the required capacitance value, and the lower the frequency, the larger the required capacitance value. The value of the capacitive reactance Xc is an important value to ensure the isolation and directivity of the coupler. In a case of a fixed requirement, for example, assuming that the directivity of the coupler is not less than a preset value (such as 18 dB), the range of Xc can be determined. The higher the frequency, the larger the ω value, and at this time, the capacitance value C is smaller, so that the product ωC of these two values can ensure that it is within a certain fixed value range to ensure that the capacitive reactance value Xc meets the actual requirements.

[0036] In this application, through the input port 1, output port 2, coupling port 3, and isolation port 4, the main line 10 extending between the input port 1 and the output port 2, and the coupling line 30 extending between the coupling port 3 and the isolation port 4; a first compensation capacitor is formed between the main line 10 and the coupling line 30. By adjusting the capacitance value of the first compensation capacitor, the isolation (ISO) of the coupler can be improved well. When the isolation is improved, the directivity index D can be improved; thereby improving the directivity and isolation of the coupler in a wide frequency band (especially in the range of two frequency points with a large span, such as [1.4 GHz, 2.69 GHz]) to meet the actual requirements.

[0037] Preferably, the capacitance value range of the first compensation capacitor is 0.5 pF to 2.2 pF. For example, the capacitance value of the first compensation capacitor is 0.8 pF, 0.9 pF, 1.0 pF, 1.5 pF, 2.0 pF, or 2.2 pF, etc.

[0038] In at least one embodiment, within the first frequency band [2.5 GHz, 2.69 GHz], the capacitance value of the first compensation capacitor is [0.5 pF, 1.5 pF], and within the second frequency band [1.42 GHz, 2.49 GHz], the capacitance value of the first compensation capacitor is [0.7 pF, 2.2 pF].

[0039] Specifically, the first compensation capacitor can be a single compensation capacitor or a combination of multiple compensation capacitors connected in parallel. In this application, as shown below Figure 3 The first compensation capacitor is the compensation capacitor C5 or the compensation capacitor C6 in the equivalent circuit, or a combination of the compensation capacitor C5 and the compensation capacitor C6 connected in parallel. In a radio frequency circuit, generally, the higher the frequency, the smaller the required capacitance value, and the lower the frequency, the larger the required capacitance value. By setting the values of the compensation capacitor C5 and / or the compensation capacitor C6, the directivity and isolation of the coupler can be improved in a wide frequency band (especially in two frequency points with a large span, such as within the range of [1.4 GHz, 2.69 GHz]) to meet actual requirements.

[0040] In a specific embodiment, as shown below Figure 3 The coupler further includes: a second compensation capacitor C7, one end of the second compensation capacitor C7 is connected to the main line 10, and the other end of the second compensation capacitor C7 is grounded.

[0041] The formula for calculating the directivity of the coupler is: D(dB) = ISO(dB) - C(dB), where D is the directivity of the coupler, ISO is the isolation of the coupler, and C is the coupling of the coupler. By adjusting the capacitance value of the second compensation capacitor C7, the odd-mode and even-mode impedances Z of the coupler at each frequency band can be adjusted. The odd-mode and even-mode impedances Z of the coupler are associated with the coefficient K, and the coefficient K = 10 C / 10 , where C is the coupling. Therefore, by adjusting the size of the second compensation capacitor C7, the directivity and isolation of the coupler can be improved in a wide frequency band (especially in two frequency points with a large span, such as [1.4 GHz, 2.69 GHz]) to meet actual requirements.

[0042] In a specific embodiment, the coupler includes: a second compensation capacitor, one end of the second compensation capacitor is connected to the main line, and the other end of the second compensation capacitor is grounded, and / or a third compensation capacitor, one end of the third compensation capacitor is connected to the coupled line, and the other end of the third compensation capacitor is grounded.

[0043] In at least one embodiment, the total capacitance value range of the second compensation capacitor C7 and the third compensation capacitor C8 is [0.2 pF, 1 pF]. For example, the total capacitance value of the second compensation capacitor C7 and the third compensation capacitor C8 is 0.2 pF, 0.4 pF, 0.6 pF, 0.8 pF, 0.9 pF, or 1 pF.

[0044] In another specific embodiment, the total capacitance value range of the second compensation capacitor C7 and the third compensation capacitor C8 is [0.2 pF, 0.6 pF]. For example: the total capacitance value of the second compensation capacitor C7 and the third compensation capacitor C8 is 0.2 pF, 0.3 pF, 0.4 pF, 0.5 pF or 0.6 pF.

[0045] In at least one embodiment, the capacitance value range of the second compensation capacitor C7 is [0.1 pF, 0.5 pF]. For example: the capacitance value of the second compensation capacitor C7 is 0.1 pF, 0.2 pF, 0.3 pF, 0.4 pF or 0.5 pF.

[0046] In another specific embodiment, the capacitance value range of the second compensation capacitor C7 is [0.1 pF, 0.3 pF]. For example: the capacitance value of the second compensation capacitor C7 is 0.1 pF, 0.2 pF, 0.3 pF.

[0047] In at least one embodiment, the capacitance value range of the third compensation capacitor C8 is [0.1 pF, 0.5 pF]. For example: the capacitance value of the third compensation capacitor C8 is 0.1 pF, 0.2 pF, 0.3 pF, 0.4 pF or 0.5 pF.

[0048] In another specific embodiment, the capacitance value range of the third compensation capacitor C8 is [0.1 pF, 0.3 pF]. For example: the capacitance value of the third compensation capacitor C8 is 0.1 pF, 0.2 pF, 0.3 pF.

[0049] In at least one embodiment, since the lower the frequency band, the larger the capacitance value of the compensation capacitor required. In this embodiment, in the first frequency band [1.42 GHz - 1.5 GHz], the total capacitance value range of the second compensation capacitor C7 and the third compensation capacitor C8 is [0.2 pF, 0.5 pF]; in the second frequency band [1.71 GHz - 2.1 GHz], the total capacitance value range of the second compensation capacitor C7 and the third compensation capacitor C8 is [0.4 pF, 0.8 pF]; in the third frequency band [[2.3 GHz - 2.69 GHz], the total capacitance value range of the second compensation capacitor C7 and the third compensation capacitor C8 is [0.5 pF, 1 pF].

[0050] Among them, the directional formula of the coupler: D(dB) = ISO(dB) - C(dB), where D: the directivity of the coupler; ISO: the isolation of the coupler; C: the coupling of the coupler. By adjusting the capacitance value of the second compensation capacitor C7 and / or the third compensation capacitor C8, the odd-mode and even-mode impedances Z of the coupler at each frequency band can be adjusted. The odd-mode and even-mode impedances Z of the coupler are also associated with the coefficient K, and the coefficient K = 10 C / 10, C is the coupling degree. Therefore, by adjusting the sizes of the second compensation capacitor C7 and / or the third compensation capacitor C8, the directivity and isolation of the coupler in a wide frequency band (especially in the range of two frequency points with a large span, for example: [1.4 GHz, 2.69 GHz]) can be improved to meet the actual requirements.

[0051] In a specific embodiment, the main line 10 further includes a first inductor L1 and a second inductor L2. The first end of the first inductor L1 is connected to the input port 1, the second end of the first inductor L1 is connected to the first end of the second inductor L2, and the second end of the second inductor L2 is connected to the output port 2.

[0052] As Figure 3 shown, the output end is on the right and the input end is on the left. The overall circuit diagram is symmetric up and down. The first end of the first inductor L1 (the port on the left side of the first inductor) is connected to the input port 1, the second end of the first inductor L1 (the port on the right side of the first inductor) is connected to the first end of the second inductor L2 (the port on the left side of the second inductor), and the second end of the second inductor L2 (the port on the right side of the second inductor) is connected to the output port 2.

[0053] In a specific embodiment, the coupled line 30 further includes a third inductor L3 and a fourth inductor L4. The first end of the third inductor L3 is connected to the isolation port 4, the second end of the third inductor L3 is connected to the first end of the fourth inductor L4, and the second end of the fourth inductor L4 is connected to the coupled port 3.

[0054] As Figure 3 shown, the output end is on the right and the input end is on the left. The overall circuit diagram is symmetric up and down. The first end of the third inductor L3 (the port on the left side of the third inductor) is connected to the input port 1, the second end of the third inductor L3 (the port on the right side of the third inductor) is connected to the first end of the fourth inductor L4 (the port on the left side of the fourth inductor), and the second end of the fourth inductor L4 (the port on the right side of the fourth inductor) is connected to the output port 2.

[0055] In a specific embodiment, as Figure 3 shown, a first coupling capacitor C6 and a second coupling capacitor C9 are also formed between the main line 10 and the coupled line 30.

[0056] In at least one embodiment, by limiting the distance between the main line and the coupled line within the range of [3 μm, 8 μm], a first coupling capacitor C6 and a second coupling capacitor C9 are also formed between the main line 10 and the coupled line 30.

[0057] In at least one embodiment, the coupler further includes a switchable branch. One end of the switchable branch is connected to the isolation port of the coupled line, and the other end of the switchable branch is grounded. The switchable branch includes: a first resistor branch, the first end of the first resistor branch is connected to the isolation port of the coupled line 30, the second end of the first resistor branch is grounded, and the first resistor branch includes at least one resistor R1; at least one capacitor branch; the capacitor branch is in parallel with the first resistor branch; the first end of the capacitor branch is connected to the isolation port of the coupled line 30, and the second end of the capacitor branch is grounded; the capacitor branch includes at least one switch and at least one capacitor.

[0058] A coupler is a device that divides a microwave power into several paths in proportion to achieve power distribution. A coupler is a commonly used radio frequency passive device in radio frequency circuit design. It couples the radio frequency power transmitted in a line to another line. The basic characteristic of a coupler is that it only couples the signal in a specified direction. A coupler has several key characteristics, including bandwidth, rated input power, insertion loss, frequency flatness, coupling coefficient, directivity, isolation, and residual voltage standing wave ratio (VSWR). Bandwidth: The bandwidth of a coupler represents the frequency range in hertz. Within this frequency range, the coupler can operate within the specified range. Rated input power: For continuous wave (CW) and pulsed input signals, the coupler has a maximum rated input power in watts. This value represents the maximum power that the device can handle without degrading performance or causing physical damage. Insertion loss: Used to describe the power loss caused by the device being inserted into the main transmission path, in decibels (dB). Frequency flatness: Frequency flatness refers to the amplitude response variation of the main transmission path within a specific bandwidth of the device. This value is a function of the input signal frequency variation, in dB. Coupling coefficient: The coupling coefficient is the ratio of the input power to the output power of the coupled port 3 when all ports of the coupler are properly terminated, in dB. The output of the coupled port 3 is proportional to the power level of the direct path (from input to output). Isolation: The power ratio between the input port 1 and the isolation port 4 when all ports are properly terminated, in dB. Directivity: The power ratio between the coupled port 3 and the isolation port 4 when all ports are properly terminated, in dB. For a three-port coupler, usually two power measurements are made: one under normal forward termination conditions and the other with the input and output ports 2 reversed. This specification is used to measure the separation between the forward and reflected components; generally, the greater the directivity, the better the performance of the coupler. Directivity cannot be measured directly and can only be calculated from the measured values of isolation and reverse isolation. Residual VSWR: The voltage standing wave ratio measured when all ports of the coupler are properly terminated. This value is used to measure the inherent impedance matching of the coupler.

[0059] In at least one embodiment, the first resistor branch includes at least one resistor R1. The first resistor branch only includes the resistor R1, and omitting the switch S1 can save the occupied area of the circuit.

[0060] In at least one embodiment, the first resistor branch may further include a switch S1, and the switch S1 is connected in parallel with the resistor R1. The first resistor branch includes the resistor R1 and the switch S1 connected in parallel, and the Ron of the switch S1 in the conducting state can be utilized to achieve more flexible adjustment of the resistance value presented by the switchable circuit.

[0061] Preferably, the first resistor branch further includes a fourth compensation capacitor C1, and the fourth compensation capacitor C1 is connected in parallel with the resistor of the first resistor branch; and / or, the capacitor branch further includes a fifth compensation capacitor C2, and the fifth compensation capacitor C2 is connected in parallel with the capacitor of the capacitor branch.

[0062] In at least one embodiment, by connecting the fourth compensation capacitor C1 to the first resistor in the first resistor branch, and / or, by connecting the fifth compensation capacitor in parallel with the capacitor in the capacitor branch, the directivity of the coupler can be improved.

[0063] In at least one embodiment, at least one capacitor branch includes a first capacitor branch and a second capacitor branch, and the capacitance value of the first capacitor branch is less than the capacitance value of the second capacitor branch.

[0064] The coupler operates in a first frequency band, the first resistor branch is closed, and both the first capacitor branch and the second capacitor branch are disconnected; the coupler operates in a second frequency band, the first resistor branch and the first capacitor branch are closed, and the second capacitor branch is disconnected; the coupler operates in a third frequency band, the first resistor branch and the second capacitor branch are closed, and the first capacitor branch is disconnected; the coupler operates in a fourth frequency band, and the first resistor branch, the first capacitor branch, and the second capacitor branch are all closed.

[0065] Wherein, the first frequency band is greater than the second frequency band, the second frequency band is greater than the third frequency band, and the third frequency band is greater than the fourth frequency band.

[0066] In at least one embodiment, the higher the operating frequency band of the coupler, the smaller the capacitance value that the switchable circuit needs to present, and the lower the operating frequency band, the larger the capacitance value that the switchable circuit needs to present. In this embodiment, an example is given with two capacitor branches (the first capacitor branch and the second capacitor branch) and one resistor branch (the first resistor branch), but it is not limited to only including the first capacitor branch and the second capacitor branch, and may also include multiple capacitor branches such as a third capacitor branch and a fourth capacitor branch.

[0067] Exemplarily, in the first frequency band: only the first resistor branch is closed, and the first capacitor branch and the second capacitor branch are both open. At this time, the capacitance value presented by the switchable circuit is the first capacitance value. In the second frequency band, the first resistor branch and the first capacitor branch are closed, and the second capacitor branch is open. At this time, the capacitance value presented by the switchable circuit is the second capacitance value; the first resistor branch and the second capacitor branch are closed, and the first capacitor branch is open. At this time, the capacitance value presented by the switchable circuit is the third capacitance value; in the fourth frequency band, the first resistor branch, the first capacitor branch, and the second capacitor branch are all closed. At this time, the capacitance value presented by the switchable circuit is the fourth capacitance value. The capacitance value that the switchable circuit needs to present is negatively correlated with the operating frequency band of the coupler. Therefore, when the first frequency band is greater than the second frequency band, the second frequency band is greater than the third frequency band, and the third frequency band is greater than the fourth frequency band, the first capacitance value is less than the second capacitance value, the second capacitance value is less than the third capacitance value, and the third capacitance value is less than the fourth capacitance value.

[0068] In this embodiment, the coupler includes a resistor branch and multiple capacitor branches connected in parallel. By changing the states of the multiple capacitor branches, the capacitance value of the capacitor connected to the isolation port of the coupler can be changed, so as to adapt to the different capacitance values required by the coupler under different operating frequency bands. And because the resistor branch and the multiple capacitor branches in this embodiment are connected in parallel, the combination of the parallel capacitor branches can not only meet the performance requirements of the coupler for large capacitance in the low frequency band, but also solve the large capacitance requirement of the coupler under the condition of small chip area, thereby saving the design area and cost.

[0069] In a radio frequency front-end system, a coupler usually needs to transmit signals of multiple different frequency bands. If different couplers are used to transmit signals of each frequency band, the system cost and area will increase. Therefore, this embodiment designs a coupler that can work in a wide frequency band range, which can save the occupied area and cost while ensuring performance.

[0070] On the other hand, most modern communication systems require high speed, high efficiency, and high bandwidth. Therefore, broadband couplers are needed to achieve signal transmission and processing. The wider the bandwidth of the coupler, the more radio frequency signals of a wider frequency band it can carry, and thus higher signal transmission rates can be achieved.

[0071] The present invention uses multiple parallel capacitor branches to change the capacitance value of the capacitor connected to the isolation port of the coupler. For a traditional coupler, in this embodiment, by changing the capacitance value of the capacitor connected to the isolation port of the coupler, the operating bandwidth of the coupler is broadened, enabling the coupler to be more widely applied, meeting the application requirements of the broadband frequency band. Moreover, the coupler in the embodiment can not only adjust the bandwidth but also adjust the standing wave ratio, enabling the coupler to better match the line and reduce power loss.

[0072] In at least one embodiment, the switchable branch can be an adjustment circuit. The adjustment circuit includes: a forward directivity adjustment circuit and a reverse directivity adjustment circuit. As Figure 3 shown, the upper part is the first resistor branch (reverse directivity adjustment circuit), and the lower part is the second resistor branch (forward directivity adjustment circuit). The forward directivity adjustment circuit and the reverse directivity adjustment circuit are symmetrical to each other and have the same structure. For the forward directivity adjustment circuit: by connecting a switchable circuit between the isolation end of the coupled line 30 and the ground, the requirements for the coupling capacitor in different frequency bands (such as LB / MB / HB) can be met, and thus the directivity and isolation of the coupler in different frequency bands can be optimized. By connecting a compensation capacitor between the isolation end of the coupled line 30 and the ground, the compensation capacitor can be an equivalent capacitor formed by the ground (GND) of the first metal layer on the substrate directly below the chip and the metal on the chip, or an equivalent capacitor formed by the ground (GND) of the first metal layer on the substrate and the ground (GND) of the second metal layer. Thus, under the requirement of miniaturized area, the directivity and isolation of the coupler are optimized. It should be noted that the ground (GND) of the first metal layer on the substrate and the ground (GND) of the second metal layer can be a whole area of the ground (GND) covered on the first metal layer or the second metal layer of the substrate, or a part of the area of the ground (GND) on the first metal layer or the second metal layer of the substrate, or an area on the first metal layer or the second metal layer of the substrate directly connected to the ground (GND).

[0073] It can be understood that the more parallel capacitor branches the coupler is connected to, the larger the total capacitance value in the circuit will be. At this time, the coupler can operate in a lower frequency band, and within the operating range of the lower frequency band, the requirement of high isolation can be met. Isolation is a measure to suppress interference taken to minimize the impact of various interferences on the receiver. In different frequency bands, the number of required parallel capacitor branches is different. To achieve strong directivity of the coupler under a wide frequency band, the more circuit combinations are needed, and the chip area and manufacturing cost will also increase accordingly.

[0074] It can be seen that the coupler in this embodiment uses multiple parallel capacitor branches to meet the wide frequency band of the coupler

[0075] For the requirements of [1.42GHz, 2.69GHz], if the coupler operates in a low-frequency circuit, the equivalent capacitance value in the circuit can be increased by closing the switch to increase the number of combined capacitors in the circuit, so as to meet the large-capacitance requirements in the low-frequency band. If the coupler operates in a higher-frequency circuit, the equivalent capacitance value in the circuit can be reduced by opening the switch to reduce the number of combined capacitors in the circuit, so as to meet the small-capacitance requirements in the high-frequency band. Preferably, in order to avoid excessive occupied area of the coupler, the coupler in this embodiment includes two capacitance branches (the first capacitance branch and the second capacitance branch) and one resistance branch (the first resistance branch).

[0076] Preferably, the first capacitance branch includes a plurality of capacitors connected in parallel.

[0077] In this application, specifically, as Figure 4 and Figure 5 shown, three branches are provided, the first branch, the second branch and the third branch. In the first branch, the capacitor C1 and the switch S1 are connected in series. In the second branch, the resistor R1 and the switch S2 are connected in series. In the third branch, the capacitor C0 and the switch S3 are connected in series. The first branch, the second branch and the third branch are connected in parallel and then connected to the fifth compensation capacitor C2.

[0078] In this application, the purpose of connecting multiple capacitors in parallel is to change the total capacitance value in the circuit. The total capacitance value after multiple capacitors are connected in parallel is: C = C1 + C2 + C3 + … + Cn. It can be seen that during the process of continuously connecting capacitors in parallel, the total capacitance value in the circuit will become larger and larger, so as to adapt to lower operating frequencies.

[0079] In the related art, the first capacitance branch includes a plurality of capacitors connected in series, and each capacitor of the first capacitance branch is connected in parallel with a switch. Specifically, as Figure 6 shown, in the first capacitance branch, the capacitor C1, the capacitor C10, the capacitor C11 and the switch S4 are connected in series, the capacitor C1 is connected in parallel with the switch S5, the capacitor C10 is connected in parallel with the switch S6, and the capacitor C11 is connected in parallel with the switch S7. As Figure 4 shown, connecting capacitors in series can also change the total capacitance value in the circuit. The capacitance value in the total circuit conforms to the following rule: 1 / C = 1 / C1 + 1 / C2 + … + 1 / Cn. It can be seen that the more capacitors are connected in series, the smaller the total capacitance value in the circuit, and the coupler can adapt to a higher-frequency operating band. Compared with the connection method of series capacitors in the related art, in this application, by connecting multiple capacitors in parallel, not only can it adapt to lower operating frequencies, but also it can save area.

[0080] In at least one embodiment, the second resistor branch further includes a sixth compensation capacitor C3, and the sixth compensation capacitor C3 is connected in parallel with the resistor R2 of the second resistor branch. By connecting the sixth compensation capacitor C3 in parallel with the second resistor in the second resistor branch, the directivity of the coupler can be improved.

[0081] Embodiment 2

[0082] This application provides a coupler 100, as Figures 1 - 6 shown. The coupler 100 includes: an input port 1, an output port 2, a coupling port 3, and an isolation port 4, a main line 10, one end of the main line 10 is connected to the input port 1, and the other end of the main line 10 is connected to the output port 2; a coupling line 30, one end of the coupling line 30 is connected to the coupling port 3, and the other end of the coupling line 30 is connected to the isolation port 4. The main line 10 and the coupling line 30 overlap at least partially in the longitudinal direction to form a first compensation capacitor.

[0083] Among them, directivity is a measure or quality factor of the ability of a coupler to distinguish incident waves and reflected waves in a transmitting system. The quality of the directivity of a coupler depends on the electric field component and magnetic field component in the coupling circuit. The directivity is optimal when the components generated by these two sources are balanced. The values of the electric field component and magnetic field component depend on the coupling capacitance and inductance on the coupling board. The coupler directivity calculation formula: D(dB) = ISO(dB) - C(dB), where D is the directivity of the coupler; ISO is the isolation of the coupler; C is the coupling of the coupler.

[0084] Among them, the impedance of a capacitor in an AC circuit is capacitive reactance Xc, and the calculation formula is Xc = 1 / (ωC) = 1 / (2πfC), where f is the frequency, with the unit Hz, and ω = 2πf is the angular frequency, with the unit 1 / s. In the RF circuit where the coupler is located, generally, the higher the frequency, the smaller the required capacitance value, and the lower the frequency, the larger the required capacitance value. The capacitive reactance value Xc is an important value to ensure the isolation and directivity of the coupler. In a case of a fixed requirement, for example, assuming that the directivity of the coupler is not less than a preset value (such as 18 dB), the value of Xc is determined. At this time, the higher the frequency, the larger the ω value, and the smaller the capacitance value C. Only in this way can the product ωc of these two values ensure to be within a certain fixed value range to ensure that the capacitive reactance value Xc meets the actual requirements.

[0085] In this application, by making the main line 10 and the coupling line 30 at least partially overlap in the longitudinal direction to form a first compensation capacitor, the capacitance value of the formed first compensation capacitor can be changed by setting the overlapping area between the main line 10 and the coupling line 30 or the coupling distance between the main line 10 and the coupling line 30. Since the capacitance value of the first compensation capacitor is related to the isolation of the coupler, therefore, by making the main line 10 and the coupling line 30 at least partially overlap in the longitudinal direction, the capacitance value of the first compensation capacitor can be flexibly adjusted, so as to improve the directivity and isolation of the coupler in a wide frequency band (especially in two frequency points with a large span, for example, within the range of [1.4 GHz, 2.69 GHz]) to meet the actual requirements.

[0086] Preferably, the capacitance value range of the first compensation capacitor is [0.5 pF, 2.2 pF]. For example: the capacitance value of the first compensation capacitor is 0.8 pF, 0.9 pF, 1.0 pF, 1.5 pF, 2.0 pF or 2.2 pF, etc.

[0087] In at least one embodiment, within the first frequency band [2.5 GHz, 2.69 GHz], the capacitance value of the first compensation capacitor is [0.5 pF, 1.5 pF], and within the second frequency band [1.42 GHz, 2.49 GHz], the capacitance value of the first compensation capacitor is [0.7 pF, 2.2 pF].

[0088] In a specific embodiment, if the operating frequency band of the coupler is within [1.42 GHz, 2.69 GHz], then the overlapping area of the projection of the first coupling line part and the main line in the longitudinal direction is S, where: 810 um 2 ≤S≤1860 um 2 .

[0089] It should be noted that the operating frequency band of the coupler within [1.42 GHz, 2.69 GHz] includes all frequency bands from 1.42 GHz to 2.69 GHz. For an interval frequency band, as long as the maximum frequency band value is less than or equal to 2.69 GHz and the minimum frequency band value is greater than or equal to 1.42 GHz, it is within the range of [1.42 GHz, 2.69 GHz]. For example: [1.5 GHz, 2 GHz], [1.42 GHz, 1.69 GHz] or [2 GHz, 2.69 GHz] are all within the range of [1.42 GHz, 2.69 GHz].

[0090] Wherein, the overlapping area of the projection of the first coupling line part and the main line in the longitudinal direction refers to the area where the first coupling line part projects onto the plane where the main line is located and overlaps with the main line, or the area where the main line projects onto the plane where the first coupling line part is located and overlaps with the first coupling line part.

[0091] In at least one embodiment, by changing the range of the area S projected by the coupling line 30 onto the main line 10 in the longitudinal direction, the capacitance value of the formed first compensation capacitor can be adjusted. Specifically, by making the range of the area S projected by the coupling line 30 onto the main line 10 in the longitudinal direction be 810um 2 ≤S≤1860um 2 , so that the capacitance value of the formed first compensation capacitor satisfies the isolation ISO and directivity index D of the coupler within the range of [1.42 GHz, 2.69 GHz] in the wide frequency band.

[0092] In a specific embodiment, the coupling line 30 includes a first coupling line portion 20 and a second coupling coil portion 40. The second coupling coil portion 40 and the main line 10 are disposed on the first metal layer; the first coupling line portion 20 is disposed on the second metal layer, and at least a part of the projection of the first coupling line portion 20 and the main line 10 in the longitudinal direction overlaps.

[0093] Specifically, at least a part of the projection of the first coupling line portion 20 and the main line 10 in the longitudinal direction overlaps to form a first compensation capacitor (for example, capacitor C5 and / or capacitor C6 in the equivalent circuit); thereby satisfying the isolation ISO and directivity index D of the coupler in the wide frequency band. As an example, the first coupling line portion 20 disposed on the second metal layer and the second coupling coil portion 40 disposed on the first metal layer can be connected by a metal via or a jumper. It can be understood that the second coupling coil portion 40 disposed on the first metal layer and the main line 10 are spaced apart and coupled to each other. As an example, the width of the second coupling coil portion 40 is greater than or equal to 8um and the length is less than or equal to 330um.

[0094] In at least one embodiment, the overlapping length when the projection of the first coupling line portion 20 and the main coil 11 overlaps in the longitudinal direction also affects the coupling coefficient of the coupler, and the overlapping length and the coupling coefficient are positively correlated. In a frequency band range (for example: sub3GHz), the overlapping length basically determines the range of the interval value of the coupling coefficient. Especially for two frequency bands with a large frequency band gap, the overlapping lengths when the first coupling line portion 20 and the main coil 11 overlap are often different (for example, there are differences in the overlapping lengths of sub3GHz, sub5GHz, and sub6GHz).

[0095] In a specific embodiment, the distance between the second coupling coil portion 40 between the main lines 10 is within the range of [3um, 8um]. For example: the distance between the second coupling coil portion 40 between the main lines 10 is 3um, 4um, 5um, 6um, 7um or 8um. In a specific embodiment, the distance range between the second coupling coil portion 40 between the main lines 10 is [3um, 6um]. For example: the distance between the second coupling coil portion 40 between the main lines 10 is 3um, 4um, 5um or 6um.

[0096] In at least one embodiment, the second coupling coil portion 40 is coupled to the main line 10 to form an equivalent capacitance (e.g., capacitance C9) in the equivalent circuit. The capacitance value of the capacitance C9 affects the isolation and directivity index D of the coupler 100. The capacitance value of the capacitance C9 is related to the distance between the second coupling coil portion 40 and the main line 10. The smaller the distance between the second coupling coil portion 40 and the main line 10, the larger the capacitance value of the formed equivalent capacitance. In this application, by defining the distance between the second coupling coil portion 40 between the main lines 10 within the range of [3um, 8um], not only can the capacitance value of the formed equivalent capacitance be increased to improve the isolation and directivity index of the coupler 100, but also the miniaturization setting of the coupler can be satisfied.

[0097] In a specific embodiment, the first end of the first coupling line portion 20 is connected to the first end of the second coupling coil portion 40 through a first through hole; the coupling line 20 further includes a first extension portion 21, the first extension portion 21 extends from the first end of the first coupling line portion 20, and the first extension portion 21 at least partially overlaps with the projection of the second coupling coil portion 40 in the longitudinal direction, and / or, the coupler 100 further includes a second extension portion 42, the second extension portion extends from the first end of the second coupling coil portion 40, and the second extension portion 42 at least partially overlaps with the projection of the first coupling line portion 31 in the longitudinal direction.

[0098] In at least one embodiment, the first extension portion 21 at least partially overlaps with the projection of the second coupling coil portion 40 in the longitudinal direction to form a compensation capacitance C7 in the equivalent circuit; and / or, the second extension portion at least partially overlaps with the projection of the first coupling line portion 20 in the longitudinal direction to form a compensation capacitance C8.

[0099] Based on the coupler directivity calculation formula: D(dB) = ISO(dB) - C(dB). D is the directivity of the coupler; ISO is the isolation of the coupler; C is the coupling of the coupler. In this application, by extending from the first end of the first coupling line portion 20 to form a first extension portion 21, the first extension portion 21 at least partially overlaps with the projection of the second coupling coil portion 40 in the longitudinal direction, and / or, by extending from the first end of the second coupling coil portion 40 to form a second extension portion, the second extension portion at least partially overlaps with the projection of the first coupling line portion in the longitudinal direction to form a compensation capacitance C7 and / or a compensation capacitance C8. By setting the projection area of the first extension portion 21 and the second coupling coil portion 40 in the longitudinal direction, and the overlapping of the second extension portion and the projection of the first coupling line portion 20 in the longitudinal direction, the capacitance values of the compensation capacitance C7 and the compensation capacitance C8 can be adjusted, and further the odd-mode and even-mode impedances Z of the coupler at each frequency band can be adjusted. The odd-mode and even-mode impedances Z of the coupler are associated with the coefficient K, and the coefficient K = 10 C / 10, where C is the coupling degree. Therefore, by adjusting the sizes of the compensation capacitor C7 and / or the compensation capacitor C8, the directivity and isolation of the coupler in a wide frequency band (especially in the range of two frequency points with a large span, for example: [1.4 GHz, 2.69 GHz]) can be improved to meet the actual requirements.

[0100] In a specific embodiment, the first end of the first coupled line portion 20 is connected to the first end of the second coupled coil portion 40 through a first through hole; the coupled line 30 further includes a first extension portion 21 extending from the first end of the first coupled line portion 20; the coupler 100 further includes a second extension portion, and the second extension portion 42 extends from the first end of the second coupled coil portion 40; at least a part of the projections of the first extension portion 21 and the second extension portion 42 in the longitudinal direction overlap.

[0101] In at least one embodiment, at least a part of the projections of the first extension portion 21 and the second extension portion 42 in the longitudinal direction overlap, so that the first extension portion 21 and the second extension portion form a compensation capacitor. By setting the overlapping area of the projections of the first extension portion 21 and the second extension portion 42 in the longitudinal direction, the size of the formed compensation capacitor can be changed, thereby improving the directivity and isolation of the coupler in a wide frequency band (especially in the range of two frequency points with a large span, for example: [1.4 GHz, 2.69 GHz]) to meet the actual requirements.

[0102] In a specific embodiment, the second end of the first coupled line portion 20 is connected to the second end of the second coupled coil portion 40 through a second through hole; the coupled line 30 further includes a third extension portion 23 extending from the second end of the first coupled line portion 20, and at least a part of the projection of the third extension portion 23 and the second coupled coil portion 40 in the longitudinal direction overlaps, and / or the coupler 100 further includes a fourth extension portion extending from the first end of the second coupled coil portion 40, and at least a part of the projection of the fourth extension portion and the first coupled line portion 20 in the longitudinal direction overlaps.

[0103] In at least one embodiment, the third extension portion 23 extends from the second end of the first coupled line portion 20, at least a part of the projection of the third extension portion 23 and the second coupled coil portion 40 in the longitudinal direction overlaps, the fourth extension portion extends from the first end of the second coupled coil portion 40, and at least a part of the projection of the fourth extension portion and the first coupled line portion 20 in the longitudinal direction overlaps, which can form a compensation capacitor; by setting the overlapping area of the projection of the third extension portion 23 and the second coupled coil portion 40 in the longitudinal direction, and setting the overlapping area of the projection of the fourth extension portion and the first coupled line portion 20 in the longitudinal direction, the size of the formed compensation capacitor can be changed, and then the odd-mode and even-mode impedances Z of the coupler at each frequency band can be adjusted. The odd-mode and even-mode impedances Z of the coupler are associated with the coefficient K, and the coefficient K = 10 C / 10, C is the coupling degree. Therefore, by adjusting the magnitudes of the compensation capacitor C7 and / or the compensation capacitor C8, the directivity and isolation of the coupler in a wide frequency band (especially in the range of two frequency points with a large span, such as [1.4 GHz, 2.69 GHz]) can be improved to meet the actual requirements.

[0104] As an example, since the coupler directivity calculation formula is D(dB) = ISO(dB) - C(dB); where D is the directivity of the coupler; ISO is the isolation of the coupler; C is the coupling degree of the coupler, the reverse directivity of the coupler is affected by setting the compensation capacitor, such that the reverse directivity of the coupler: D2(dB) ≥ 14 dB, or the forward directivity of the coupler is affected by setting the compensation capacitor, such that the forward directivity of the coupler: D1(dB) ≥ 20 dB.

[0105] In a specific embodiment, the second end of the first coupling line portion 20 is connected to the second end of the second coupling line portion through a second through hole; the coupling line 30 further includes a third extension portion 23, and the third extension portion 23 extends from the second end of the first coupling line portion 20; the coupler 100 further includes a fourth extension portion, and the fourth extension portion extends from the second end of the second coupling coil portion 40; the projections of the third extension portion 23 and the fourth extension portion 44 in the longitudinal direction at least partially overlap.

[0106] In at least one embodiment, the third extension portion 23 extends from the second end of the first coupling line portion 20, the fourth extension portion 44 extends from the second end of the second coupling coil portion 40, and the projections of the third extension portion 23 and the fourth extension portion in the longitudinal direction at least partially overlap to form a compensation capacitor. By setting the overlapping area of the projections of the third extension portion 23 and the fourth extension portion in the longitudinal direction, the magnitude of the formed compensation capacitor can be changed, thereby improving the isolation of the coupler, and further affecting the directivity of the coupler to improve the directivity and isolation of the coupler in a wide frequency band (especially in the range of two frequency points with a large span, such as [1.4 GHz, 2.69 GHz]).

[0107] In a specific embodiment, if the operating frequency band of the coupler 100 is in the range of [1.42 GHz, 2.69 GHz], then the length range of the first extension portion 21 is [6 μm, 12 μm], and / or the length range of the second extension portion is [6 μm, 12 μm].

[0108] Specifically, at least partial overlap of the projections of the first extension portion 21 and the second coupling coil portion 40 in the longitudinal direction can form a compensation capacitor (e.g., the second compensation capacitor C7) in the equivalent circuit. At least partial overlap of the projections of the second extension portion and the first coupling line portion in the longitudinal direction can form a compensation capacitor (e.g., the third compensation capacitor C8) in the equivalent circuit. At least partial overlap of the projections of the first extension portion 21 and the second extension portion in the longitudinal direction can also form a compensation capacitor in the equivalent circuit.

[0109] Wherein, the lengths of the first extension portion 21 and the second extension portion are both related to the operating frequency of the coupler. To meet the directivity at the isolation end of the coupler, the higher the operating frequency of the coupler, the shorter the lengths of the first extension portion 21 and the second extension portion. In this embodiment, to meet the directivity and isolation of the coupler within the operating frequency band of [1.42 GHz, 2.69 GHz], the length of the first extension portion 21 is set to a length range of [6 μm, 12 μm], and the length of the second extension portion is set to a length range of [6 μm, 12 μm]. For example: the length of the first extension portion 21 is 9 μm, 10 μm or 12 μm, etc. The length of the second extension portion is 9 μm, 10 μm or 12 μm, etc.; thereby, the directivity and isolation of the coupler in the wide frequency band (especially within the range of two frequency points with a large span, e.g., [1.4 GHz, 2.69 GHz]) can be improved to meet the actual requirements. In the actual application process, a compromise selection can be made in combination with the operating frequency and area of the coupler. Optionally, the lengths of the first extension portion and the second extension portion can be the same or different.

[0110] In a specific embodiment, if the operating frequency band of the coupler 100 is within the range of [1.42 GHz, 2.69 GHz], then the length range of the third extension portion is [6 μm, 12 μm], and / or the length range of the fourth extension portion is [6 μm, 12 μm].

[0111] In at least one embodiment, at least partial overlap of the projections of the third extension portion and the second coupling coil portion in the longitudinal direction can form a compensation capacitor in the equivalent circuit. At least partial overlap of the projections of the fourth extension portion and the first coupling line portion in the longitudinal direction. At least partial overlap of the projections of the third extension portion and the fourth extension portion in the longitudinal direction can also form a compensation capacitor in the equivalent circuit.

[0112] Among them, the lengths of the third extension part and the fourth extension part are both related to the operating frequency of the coupler. To meet the directivity at the isolation end of the coupler, the higher the operating frequency of the coupler, the shorter the lengths of the third extension part and the fourth extension part. In this embodiment, to meet the directivity and isolation of the coupler within the operating frequency band of [1.42 GHz, 2.69 GHz], the lengths of the third extension part and the fourth extension part are set to be in the range of [6 μm, 12 μm]. For example: the length of the third extension part is 9 μm, 10 μm or 12 μm, etc. The length of the fourth extension part is 9 μm, 10 μm or 12 μm, etc.; thus, the directivity and isolation of the coupler in the wide frequency band (especially within the range of two frequency points with a large span, such as [1.4 GHz, 2.69 GHz]) can be improved to meet the actual requirements. In the actual application process, a trade-off selection can be made in combination with the operating frequency and area of the coupler. Optionally, the lengths of the third extension part and the fourth extension part can be the same or different.

[0113] In a specific embodiment;

[0114] If the coupler is within the operating frequency band of [1.42 GHz, 1.5 GHz], the length range of the first extension part is [8 μm, 12 μm], and / or the length range of the second extension part is [8 μm, 12 μm];

[0115] If the coupler is within the operating frequency band of [1.71 GHz, 2.1 GHz], the length range of the first extension part is [7 μm, 9 μm], and / or the length range of the second extension part is [7 μm, 9 μm];

[0116] If the coupler is within the operating frequency band of [2.3 GHz, 2.69 GHz], the length range of the first extension part is [6 μm, 8 μm], and / or the length range of the second extension part is [6 μm, 8 μm].

[0117] In a specific embodiment;

[0118] If the operating frequency band of the coupler is within the range of [1.42 GHz, 2.69 GHz], the length range of the third extension part is [6 μm, 12 μm], and / or the length range of the fourth extension part is [6 μm, 12 μm].

[0119] In at least one embodiment, the higher the operating frequency band of the coupler, the smaller the lengths of the first extension part 21 and the second extension part, and the lower the operating frequency band, the larger the lengths of the first extension part 21 and the second extension part. In the actual application process, the lengths of the first extension part 21 and the second extension part can be flexibly adjusted according to the operating frequency band of the coupler 100.

[0120] In a specific embodiment;

[0121] If the coupler operates within the working frequency band range of [1.42 GHz, 1.5 GHz], the length range of the third extension part is [8 μm, 12 μm], and / or the length range of the fourth extension part is [8 μm, 12 μm];

[0122] If the coupler operates within the working frequency band range of [1.71 GHz, 2.1 GHz], the length range of the third extension part is [7 μm, 9 μm], and / or the length range of the fourth extension part is [7 μm, 9 μm];

[0123] If the coupler operates within the working frequency band range of [2.3 GHz, 2.69 GHz], the length range of the third extension part is [6 μm, 8 μm], and / or the length range of the fourth extension part is [6 μm, 8 μm].

[0124] In at least one embodiment, the higher the working frequency band of the coupler, the smaller the lengths of the third extension part and the fourth extension part, and the lower the working frequency band of the coupler, the larger the lengths of the third extension part and the fourth extension part. In the actual application process, the lengths of the third extension part and the fourth extension part can be flexibly adjusted according to the working frequency band of the coupler 100.

[0125] In a specific embodiment; since at least part of the projection of the first coupling line part 20 on the main line 10 in the longitudinal direction overlaps to form the compensation capacitor C5 in the equivalent circuit, the capacitive reactance value of the radio frequency circuit where the coupler is located can be adjusted, thereby ensuring the isolation degree and directivity of the coupler within a wide frequency band range. The higher the working frequency band of the coupler, the smaller the overlapping area of the first coupling line part 20 on the main line 10; the lower the working frequency band of the coupler, the larger the overlapping area of the first coupling line part 20 on the main line 10. The higher the working frequency band of the coupler, the smaller the required capacitance, so that the overlapping area of the first coupling line part 20 on the main line 10 is smaller; the lower the working frequency band of the coupler, the larger the required capacitance, so that the overlapping area of the first coupling line part 20 on the main line 10 is larger; therefore, by setting the overlapping area of the projection of the first coupling line part 20 on the main line 10 in the longitudinal direction, the requirements of high isolation and directivity of the coupler within a wide frequency band range (especially at two frequency points with a large span, for example: (1.4 GHz (left sideband of the low frequency) - 2.69 GHz (right sideband of the high frequency)) can be met.

[0126] In a specific embodiment;

[0127] If the coupler operates within the working frequency band range of [1.42 GHz, 1.5 GHz], the area range of the projection of the first coupling line part on the main line is [810 μm, 900 μm];

[0128] If the coupler operates within the frequency band of [1.71 GHz, 2.1 GHz], the area range of the projection of the first coupled line portion on the main line is [1092 um, 1200 um,];

[0129] If the coupler operates within the frequency band range of [2.3 GHz, 2.69 GHz], the area range of the projection of the first coupled line portion on the main line is [1365 um, 1500 um].

[0130] In at least one embodiment, if the operating frequency band of the coupler 100 is within the range of [1.42 GHz, 2.69 GHz], the width range of the projection of the first coupled line portion 20 on the main line 10 is [3 um, 15 um]. For example: the width of the projection of the first coupled line portion 20 on the main line 10 is 3 um, 7 um, 10 um, 12 um, 14 um, or 15 um, etc.

[0131] In at least one embodiment, if the operating frequency band of the coupler 100 is within the range of [1.42 GHz, 2.69 GHz], the width range of the projection of the first coupled line portion 20 on the main line 10 is [3 um, 10 um]. For example: the width of the projection of the first coupled line portion 20 on the main line 10 is 3 um, 5 um, 6 um, 8 um, 9 um, or 10 um, etc.

[0132] In this embodiment, the width of the projection of the first coupled line portion 20 on the main line 10 in the longitudinal direction can be set to meet the requirements of high isolation and directivity for the coupler within the operating frequency band range of [1.42 GHz, 2.69 GHz] (especially at two frequency points with a large span, such as (1.4 GHz (left sideband of the low frequency) - 2.69 GHz (right sideband of the high frequency)).

[0133] In a specific embodiment, the second coupled coil portion includes a first coupled segment (34) and a second coupled segment (35). The first coupled segment (34) is connected to the first end of the first coupled line portion 20 through a first through hole, and the second coupled segment (35) is connected to the second end of the first coupled line portion 20 through a second through hole. Among them, both the first coupled segment (34) and the second coupled segment (35) are disposed on the second metal layer and are connected to the first coupled line portion 20 disposed on the first metal layer through through holes. Optionally, the first through hole and the second through hole can be metal through holes.

[0134] In at least one embodiment, participate in the following Figure 2As described above, the first coupling section (34) and the second coupling section (35) are oppositely arranged, and the extending directions of the first coupling section (34) and the second coupling section (35) are the same. The extending directions of the first coupling section (34) and the second coupling section (35) are different from the extending direction of the first coupling line portion 20. Preferably, the extending directions of the first coupling section (34) and the second coupling section (35) are perpendicular to the extending direction of the first coupling line portion 20. For example, the extending direction of the first coupling line portion 20 is the vertical direction, and the extending directions of the first coupling section (34) and the second coupling section (35) are the horizontal directions.

[0135] In a specific embodiment, the extending direction of the first extension portion extending from the first end of the first coupling line portion is the same as the extending direction of the first coupling section, and / or the extending direction of the third extension portion extending from the second end of the first coupling line portion is the same as the extending direction of the second coupling section.

[0136] In at least one embodiment, the extending direction of the first extension portion extending from the first end of the first coupling line portion is the same as the extending direction of the first coupling section, and the first extension portion and the first coupling section overlap at least partially in the longitudinal direction to form a compensation capacitor. And / or the extending direction of the third extension portion extending from the second end of the first coupling line portion is the same as the extending direction of the second coupling section, and the third extension portion and the second coupling section overlap at least partially in the longitudinal direction to form a compensation capacitor; thereby, without increasing the occupied area, the lengths of the first extension portion and the third extension portion can be flexibly adjusted, and further, the overlapping area of the projection of the first extension portion and the first coupling section in the longitudinal direction, and the overlapping area of the projection of the third extension portion and the second coupling section in the longitudinal direction can be flexibly adjusted, so as to improve the directivity and isolation degree of the coupler in the wide frequency band (especially in the range of two frequency points with a large span, such as [1.4 GHz, 2.69 GHz]).

[0137] In a specific embodiment, the second coupling coil portion further includes a third coupling section (31), a fourth coupling section (32), a fifth coupling section (33), and a sixth coupling section (36). The third coupling section (31) is oppositely arranged with respect to the main line. The fourth coupling section (32) extends from the first end of the third coupling section (31) in a direction away from the main line. The fifth coupling section (33) extends from the second end of the third coupling section (31) in a direction away from the main coil. One end of the sixth coupling section (36) is connected to the fourth coupling section (32), and the other end is connected to the fifth coupling section (33).

[0138] Refer to the following Figure 1 andFigure 2 As shown, the third coupling section (31) and the main line 11 are oppositely arranged and coupled to each other. The first coupling line portion 21 is disposed in the upper region of the third coupling section (31). The fourth coupling section (32) extends from the first end of the third coupling section (31) in a direction away from the main line, and the fifth coupling section (33) extends from the second end of the third coupling section (31) in a direction away from the main coil. One end of the sixth coupling section (36) is connected to the fourth coupling section (32), and the other end is connected to the fifth coupling section (33). In this embodiment, the third coupling section (31), the fourth coupling section (32), the fifth coupling section (33), and the sixth coupling section (36) are connected to form a coupling coil similar to a quadrilateral to form a branch-line coupler. Compared with a conventional coupled-line coupler, the branch-line coupler has performance advantages of low loss, good directivity, and high isolation.

[0139] In at least one embodiment, the first coupling section (34), the second coupling section (35), the third coupling section (31), the fourth coupling section (32), the fifth coupling section (33), and the sixth coupling section (36) can be arranged as straight line segments or as curved line segments, and the specific shape can be selected according to the actual situation, which will not be elaborated here.

[0140] Preferably, the first coupling section 31 is connected to the first end of the first coupling line portion 20 through a first through hole, and the second coupling section 32 is connected to the second end of the first coupling line portion 20 through a second through hole.

[0141] Preferably, the extending direction of the first extension portion 21 extending from the first end of the first coupling line portion 20 is the same as the extending direction of the first coupling section 31, and / or the extending direction of the third extension portion 23 extending from the second end of the first coupling line portion 20 is the same as the extending direction of the second coupling section 32.

[0142] Specifically, by arranging the first extension portion 21, the second extension portion, the third extension portion 23, and the fourth extension portion 44 at different positions and with different structures, the coupler 100 can achieve the first compensation capacitor C5, the second compensation capacitor C7, and the third compensation capacitor C8 in various ways, which will not be elaborated here. The interaction of the first compensation capacitor C5, the second compensation capacitor C7, and the third compensation capacitor C8 can not only increase the value of the isolation degree ISOSO but also improve the directivity index D. At the same time, within a relatively wide operating frequency band range, the area of the coupler 100 can be set small enough to achieve miniaturization and wideband, and can also meet the requirements of high isolation.

[0143] As an example, the length of the second coupled coil portion 40 is less than or equal to 304 um, the length of the second coupled coil segment 32 is less than or equal to 311 um; the length of the third coupled coil segment 33 is less than or equal to 311 um.

[0144] Preferably, in the present application, in order to ensure that the area of the coupled line 30 is minimized as much as possible in the wide frequency band [1.42 GHz, 2.69 GHz], and also to meet the requirements of the directivity of the coupler (for example: the forward directivity is 20 dB), the length of the second coupled coil portion 40 is less than or equal to 304 um, the length of the second coupled coil segment 32 is less than or equal to 311 um; the length of the third coupled coil segment 33 is less than or equal to 311 um.

[0145] In a specific embodiment, at least a part of the projection of the first extension portion and the second coupled coil portion in the longitudinal direction overlaps to form a second compensation capacitor, and / or at least a part of the projection of the third extension portion and the second coupled coil portion in the longitudinal direction overlaps to form a second compensation capacitor, and / or at least a part of the projection of the first extension portion and the second extension portion in the longitudinal direction overlaps to form a second compensation capacitor.

[0146] At least a part of the projection of the second extension portion and the first coupled line portion in the longitudinal direction overlaps to form a third compensation capacitor, and / or at least a part of the projection of the fourth extension portion and the first coupled line portion in the longitudinal direction overlaps to form a third compensation capacitor, and / or at least a part of the projection of the third extension portion and the fourth extension portion in the longitudinal direction overlaps to form a third compensation capacitor; wherein, the first compensation capacitor, the second compensation capacitor and the third compensation capacitor are configured such that in the operating frequency band range of [1.42 GHz, 2.69 GHz] of the coupler, the coupling degree of the coupler is greater than or equal to a preset value, for example: the preset value is 15 dB. In this embodiment, under the combined action of the first compensation capacitor, the second compensation capacitor and the third compensation capacitor, the directivity and isolation degree of the coupler in the wide frequency band (especially in the range of two frequency points with a large span, for example: [1.4 GHz, 2.69 GHz]) are improved to meet the actual requirements.

[0147] Embodiment 3

[0148] A radio frequency module includes the coupler 100 as described above. The coupler 100 includes: an input port 1, an output port 2, a coupling port 3, and an isolation port 4.

[0149] Main line 10, one end of the main line 10 is connected to the input port 1, and the other end of the main line 10 is connected to the output port 2; coupling line 30, one end of the coupling line 30 is connected to the coupling port 3, and the other end of the coupling line 30 is connected to the isolation port 4. The main line 10 and the coupling line 30 overlap at least partially in the longitudinal direction to form a first compensation capacitor.

[0150] Embodiment 4

[0151] A communication device includes the radio frequency module as described above. The radio frequency module includes: A radio frequency module includes the coupler 100 as described above. The coupler 100 includes: an input port 1, an output port 2, a coupling port 3, and an isolation port 4. Main line 10, one end of the main line 10 is connected to the input port 1, and the other end of the main line 10 is connected to the output port 2; coupling line 30, one end of the coupling line 30 is connected to the coupling port 3, and the other end of the coupling line 30 is connected to the isolation port 4. The main line 10 and the coupling line 30 overlap at least partially in the longitudinal direction to form a first compensation capacitor.

[0152] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A coupler, characterized in that, it includes: an input port, an output port, a coupling port and an isolation port, a main line extending between the input port and the output port, and a coupling line extending between the coupling port and the isolation port, a first compensation capacitor is formed between the main line and the coupling line.

2. The coupler according to claim 1, characterized in that, it includes: a second compensation capacitor, one end of the second compensation capacitor is connected to the main line, the other end of the second compensation capacitor is grounded, and / or, a third compensation capacitor, one end of the third compensation capacitor is connected to the coupling line, the other end of the third compensation capacitor is grounded.

3. The coupler according to claim 1, characterized in that, a first coupling capacitor and a second coupling capacitor are further formed between the main line and the coupling line.

4. The coupler according to claim 1, characterized in that, it further includes a switchable branch, one end of the switchable branch is connected to the isolation port of the coupling line, the other end of the switchable branch is grounded, and the switchable branch includes: a first resistor branch, the first resistor branch includes at least one resistor; at least one capacitor branch; the capacitor branch is in parallel with the first resistor branch, and each capacitor branch includes at least one switch and at least one capacitor.

5. The coupler according to claim 4, characterized in that, the first resistor branch further includes a fourth compensation capacitor, the fourth compensation capacitor is in parallel with the resistor of the first resistor branch, and / or, the capacitor branch further includes a fifth compensation capacitor, the fifth compensation capacitor is in parallel with the capacitor of at least one capacitor branch.

6. The coupler according to claim 4, characterized in that, the at least one capacitor branch includes a first capacitor branch and a second capacitor branch, and the capacitance value of the first capacitor branch is less than that of the second capacitor branch; if the coupler operates in the first frequency band, the first resistor branch is closed, and both the first capacitor branch and the second capacitor branch are open; if the coupler operates in the second frequency band, the first resistor branch and the first capacitor branch are closed, and the second capacitor branch is open; if the coupler operates in the third frequency band, the first resistor branch and the second capacitor branch are closed, and the first capacitor branch is open; if the coupler operates in the fourth frequency band, the first resistor branch, the first capacitor branch and the second capacitor branch are all closed; wherein, the first frequency band is greater than the second frequency band, the second frequency band is greater than the third frequency band, and the third frequency band is greater than the fourth frequency band.

7. A coupler, characterized in that, it includes an input port; an output port; a coupling port; an isolation port; a main line, one end of the main line is connected to the input port, and the other end is connected to the output port; a coupling line, one end of the coupling line is connected to the coupling port, and the other end is connected to the isolation port; the main line and the coupling line overlap at least partially in the longitudinal direction to form a first compensation capacitor.

8. The coupler according to claim 7, characterized in that, If the operating frequency band of the coupler is within Within the range of [[1.42GHz, 2.69GHz]], the overlapping area of the projection in the longitudinal direction between the first coupled line portion and the main line is S, where: 810um 2 ≤ S ≤ 1860um 2 .

9. The coupler according to claim 7, characterized in that the coupling line includes a first coupling line portion and a second coupling coil portion, the second coupling coil portion and the main line are disposed on a first metal layer; the first coupling line portion is disposed on a second metal layer, and at least a part of the projection of the first coupling line portion and the main line in the longitudinal direction overlaps.

10. The coupler according to claim 9, characterized in that the distance between the second coupling coil portion and the main line is within the range of [3um, 8um].

11. The coupler according to claim 9, characterized in that the first end of the first coupling line portion is connected to the first end of the second coupling coil portion through a first through hole; the coupler further includes a first extension portion, the first extension portion extends from the first end of the first coupling line portion, and at least a part of the projection of the first extension portion and the second coupling coil portion in the longitudinal direction overlaps, and / or, the coupler further includes a second extension portion, the second extension portion extends from the first end of the second coupling coil portion, and at least a part of the projection of the second extension portion and the first coupling line portion in the longitudinal direction overlaps.

12. The coupler according to claim 9, characterized in that it includes: the first end of the first coupling line portion is connected to the first end of the second coupling coil portion through a first through hole; the coupler further includes a first extension portion, the first extension portion extends from the first end of the first coupling line portion; the coupler further includes a second extension portion, the second extension portion extends from the first end of the second coupling coil portion; at least a part of the projection of the first extension portion and the second extension portion in the longitudinal direction overlaps.

13. The coupler according to claim 9, characterized in that it includes: the second end of the first coupling line portion is connected to the second end of the second coupling coil portion through a second through hole; the coupler further includes a third extension portion, the third extension portion extends from the second end of the first coupling line portion, and at least a part of the projection of the third extension portion and the second coupling coil portion in the longitudinal direction overlaps, and / or, the coupler further includes a fourth extension portion, the fourth extension portion extends from the first end of the second coupling coil portion, and at least a part of the projection of the fourth extension portion and the first coupling line portion in the longitudinal direction overlaps.

14. The coupler according to claim 9, characterized in that it includes: the second end of the first coupling line portion is connected to the second end of the second coupling coil portion through a second through hole; the coupling line further includes a third extension portion, the third extension portion extends from the second end of the first coupling line portion; the coupler further includes a fourth extension portion, the fourth extension portion extends from the second end of the second coupling coil portion; at least a part of the projection of the third extension portion and the fourth extension portion in the longitudinal direction overlaps.

15. The coupler according to claim 9, characterized in that it includes: If the operating frequency band of the coupler is in the range of [1.42 GHz, 2.69 GHz], the width range of the projection of the first coupling line portion on the main line is [3 μm, 15 μm].

16. The coupler according to claim 9, wherein, if the operating frequency band of the coupler is in the range of [1.42 GHz, 1.5 GHz], the area range of the projection of the first coupling line portion on the main line is [810 μm, 900 μm]; if the operating frequency band of the coupler is in the range of [1.71 GHz, 2.1 GHz], the area range of the projection of the first coupling line portion on the main line is [1092 μm, 1200 μm]; if the operating frequency band of the coupler is in the range of [2.3 GHz, 2.69 GHz], the area range of the projection of the first coupling line portion on the main line is [1365 μm, 1500 μm].

17. The coupler according to claim 11 or 12, wherein, comprising: if the operating frequency band of the coupler is in the range of [1.42 GHz, 2.69 GHz], the length range of the first extension portion is [6 μm, 12 μm], and / or the length range of the second extension portion is [6 μm, 12 μm].

18. The coupler according to claim 11 or 12, wherein, comprising: if the operating frequency band of the coupler is in the range of [1.42 GHz, 1.5 GHz], the length range of the first extension portion is [8 μm, 12 μm], and / or the length range of the second extension portion is [8 μm, 12 μm]; if the operating frequency band of the coupler is in the range of [1.71 GHz, 2.1 GHz], the length range of the first extension portion is [7 μm, 9 μm], and / or the length range of the second extension portion is [7 μm, 9 μm]; if the operating frequency band of the coupler is in the range of [2.3 GHz, 2.69 GHz], the length range of the first extension portion is [6 μm, 8 μm], and / or the length range of the second extension portion is [6 μm, 8 μm].

19. The coupler according to claim 13 or 14, wherein, if the operating frequency band of the coupler is in the range of [1.42 GHz, 2.69 GHz], the length range of the third extension portion is [6 μm, 12 μm], and / or the length range of the fourth extension portion is [6 μm, 12 μm].

20. The coupler according to claim 13 or 14, wherein, comprising: if the operating frequency band of the coupler is in the range of [1.42 GHz, 1.5 GHz], the length range of the third extension portion is [8 μm, 12 μm], and / or the length range of the fourth extension portion is [8 μm, 12 μm]; If the coupler operates within the working frequency band range of [1.71 GHz, 2.1 GHz], the length range of the third extension part is [7 μm, 9 μm], and / or the length range of the fourth extension part is [7 μm, 9 μm]; If the coupler operates within the working frequency band range of [2.3 GHz, 2.69 GHz], the length range of the third extension part is [6 μm, 8 μm], and / or the length range of the fourth extension part is [6 μm, 8 μm].

21. The coupler according to claim 11, characterized in that, the second coupling coil part includes a first coupling segment and a second coupling segment. The first coupling segment is connected to the first end of the first coupling wire part through a first through hole, and the second coupling segment is connected to the second end of the first coupling wire part through a second through hole.

22. The coupler according to claim 21, characterized in that, the extending direction of the first extension part extending from the first end of the first coupling wire part is the same as the extending direction of the first coupling segment, and / or the extending direction of the third extension part extending from the second end of the first coupling wire part is the same as the extending direction of the second coupling segment.

23. The coupler according to claim 9, characterized in that, the second coupling coil part further includes a third coupling segment, a fourth coupling segment, a fifth coupling segment and a sixth coupling segment. The third coupling segment is disposed opposite to the main wire. The fourth coupling segment extends from the first end of the third coupling segment away from the main coil. The fifth coupling segment extends from the second end of the third coupling segment away from the main coil. One end of the sixth coupling segment is connected to the fourth coupling segment, and the other end is connected to the fifth coupling segment.

24. The coupler according to claim 17 or 19, characterized in that, the projection of the first extension part and the second coupling coil part in the longitudinal direction at least partially overlap to form a second compensation capacitor, and / or the projection of the third extension part and the second coupling coil part in the longitudinal direction at least partially overlap to form a second compensation capacitor, and / or the projection of the first extension part and the second extension part in the longitudinal direction at least partially overlap to form a second compensation capacitor; the projection of the second extension part and the first coupling wire part in the longitudinal direction at least partially overlap to form a third compensation capacitor, and / or the projection of the fourth extension part and the first coupling wire part in the longitudinal direction at least partially overlap to form a third compensation capacitor, and / or the projection of the third extension part and the fourth extension part in the longitudinal direction at least partially overlap to form a third compensation capacitor; wherein, the first compensation capacitor, the second compensation capacitor and the third compensation capacitor are configured such that within the working frequency band range of [1.42 GHz, 2.69 GHz], the coupling degree of the coupler is greater than or equal to a preset value.

25. A radio frequency front-end module, characterized in that, it includes the coupler according to any one of claims 1-24.

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