Radio frequency isolation module and communication system

Abstract

The present application provides a radio frequency isolation module and a communication system, which can support the output of multi-band signals and has isolation capabilities to prevent reflected signals from affecting a power amplifier circuit or power amplifier module. The radio frequency isolation module has lower insertion loss and reduces intermodulation distortion. The radio frequency isolation module may include a dividing circuit, an isolation circuit, and a combining circuit. The isolation circuit includes at least one isolation branch. The dividing circuit includes an input end and N output ends. The N output ends correspond one-to-one to the N frequency bands, with one output end coupled to one isolation branch, and each output end configured to output a signal in the frequency band corresponding to the coupled isolation branch. Each isolation branch is configured to transmit a signal provided by one output end of the dividing circuit coupled to the combining circuit and to prevent a signal generated in the combining circuit from being transmitted to the input end coupled to the isolation branch. The combining circuit is coupled to an antenna and configured to combine signals transmitted over the isolation branches in the isolation circuit.

Description

Technical Field

[0001] This application relates to the field of wireless communication technologies, and more particularly, to a radio frequency isolation module and a communication system.

Background Art

[0002] Currently, remote radio units generally support radio frequency signals in one frequency band. The remote radio unit includes a power amplification module and an isolator, and the power amplification module performs power amplification processing on the radio frequency signal. The function of the isolator is generally to transmit the power-amplified signal to the antenna, separate the reflected signal generated at the antenna, and prevent the reflected signal from affecting the power amplification module.

[0003] When a remote radio unit supports radio frequency signals in multiple frequency bands, the power amplification module in the remote radio unit further needs to support more frequency bands and has the ability to output higher power. Further, the isolator in the remote radio unit also needs to operate at a higher power and the isolator can support multiple frequency bands.

[0004] The performance parameters of an isolator generally include insertion loss and intermodulation distortion. The insertion loss of an isolator generally refers to the signal loss generated when the isolator is inserted into a communication system and can be understood as signal attenuation. When two or more signals with different frequencies are applied to the same non-linear circuit, the signals are mutually modulated to generate signals with new frequencies. If a new frequency exactly falls within the bandwidth of the channel where the receiver operates, interference to the receiver occurs. This interference is generally called intermodulation distortion.

[0005] However, isolators capable of supporting multiple frequency bands exhibit relatively high insertion loss and relatively high intermodulation distortion. This results in relatively high insertion loss and relatively high intermodulation distortion in remote radio units supporting multiple frequency bands, affecting the quality of the transmitter's transmitted signal in the communication system. Therefore, applying isolators to communication systems is difficult. [Overview of the project]

[0006] Embodiments of this application provide a radio frequency isolation module and communication system that can support the output of multiband signals and have isolation capabilities to prevent reflected signals from affecting power amplification circuits or power amplification modules. The radio frequency isolation module has lower insertion loss and reduces intermodulation distortion.

[0007] According to a first aspect, the present application provides a radio frequency isolation module configured to transmit a target radio frequency signal provided by a power amplification module to an antenna. The operating frequency band of the radio frequency isolation module covers the operating frequency band of the power amplification module, and the operating frequency band of the radio frequency isolation module includes N frequency bands, where N is an integer greater than 1. The radio frequency isolation module may include a splitter circuit, an isolation circuit, and a combining circuit. The isolation circuit includes at least one isolation branch. The splitter circuit includes an input terminal and N output terminals, the input terminal being coupled to a power amplifier module and configured to receive a target radio frequency signal, the target radio frequency signal including signals in S frequency bands, where S is an integer less than or equal to N, the N output terminals corresponding one-to-one with the N frequency bands, one output terminal being coupled to one isolation branch, each output terminal being configured to output a signal in the frequency band corresponding to the coupled isolation branch, the splitter circuit is configured to split the target radio frequency signal into signals in each of the S frequency bands and to output signals using the output terminals corresponding to each frequency band. Each isolation branch is coupled to a combining circuit and is configured to transmit a signal given by one output terminal of the splitter circuit coupled to the combining circuit, preventing the signal generated in the combining circuit from being transmitted to the input terminal coupled to the isolation branch. The combining circuit is coupled to an antenna and is configured to combine the signals transmitted by the isolation branches in the isolation circuit and output the combined signal to the antenna.

[0008] In this embodiment of the present application, a splitter circuit in a radio frequency isolation module can split a target radio frequency signal and output S signals by using S output terminals of the splitter circuit. The S signals correspond one-to-one with S frequency bands, and one output terminal of the splitter circuit outputs a signal containing one frequency band. The S signals can be transmitted separately to a combining circuit by using a combined isolation branch. In this way, the requirements for the operating frequency band of the isolation branches in the isolation circuit can be reduced, an isolator or circulator with lower insertion loss and lower intermodulation distortion can be used, and each isolation branch further has the function of protecting the power amplification module by isolating the signals generated in the combining circuit.

[0009] In a possible design, the isolation circuit includes N isolation branches, each of which corresponds one-to-one with N output terminals. The operating frequency band of an isolation branch covers the frequency band corresponding to the output terminals coupled to it. In such a design, the operating frequency band of each isolation branch includes one frequency band, which reduces the requirements for the isolation branch in terms of its operating frequency band, and therefore allows the use of isolators or circulators with lower insertion loss and less intermodulation distortion.

[0010] In a possible design, the isolation circuit includes M isolation branches, where M is an integer less than N, and one of the M isolation branches is coupled to at least one of the output terminals, and the operating frequency band of each isolation branch covers the frequency band corresponding to at least one of the output terminals coupled to the isolation branch. In such a design, the operating frequency band of each isolation branch includes the frequency band corresponding to the output terminal coupled to each isolation branch, and the operating frequency band of each isolation branch may not need to include N frequency bands. This reduces the requirements of the isolation branches for their operating frequency band, and therefore the isolation branches can use isolators or circulators with lower insertion loss and lower intermodulation distortion.

[0011] In any one of the possible designs described above, the splitting circuit may include at least one splitter. In any one of the possible designs described above, the isolation branch may include a circulator.

[0012] In any one of the possible designs described above, the combining circuit may include a multiband combiner. Optionally, the combining circuit may further include at least one filter, the at least one filter may correspond one-to-one with at least one isolation branch. Each isolation branch may be coupled to the multiband combiner by using its corresponding filter. The operating frequency bandwidth of each filter covers the operating frequency bandwidth of the isolation branch coupled to the filter. Each filter may be configured to perform filtering on the signal given by the coupled isolation branch, for example, filtering out noise signals.

[0013] Optionally, the operating frequency band of the radio frequency isolation module may cover at least two of the following frequency bands: 758 MHz to 960 MHz, 1.8 GHz, 2.1 GHz, or 2.6 GHz. The operating frequency band of the radio frequency isolation module is not particularly limited in this application and is described only as an example for the purposes of this specification.

[0014] According to a second aspect, one embodiment of the present application provides a communication system comprising a transmitter, a power amplification module, and a radio frequency isolation module provided in any one of the first aspect and a possible design of the first aspect. The transmitter is configured to generate a first radio frequency signal. The power amplification module is coupled separately to the transmitter and the radio frequency isolation module and is configured to amplify the first radio frequency signal to obtain a second radio frequency signal and to output the second radio frequency signal to the radio frequency isolation module. The radio frequency isolation module is configured to be coupled to an antenna and is configured to transmit the second radio frequency signal to the antenna.

[0015] In this embodiment of the present application, the radio frequency isolation module in the communication system has lower insertion loss and reduces intermodulation distortion. Furthermore, the radio frequency isolation module is positioned between the antenna and the power amplification module to isolate the antenna from the power amplification module and prevent the signal at the antenna from affecting the power amplification module.

[0016] In a possible design, the power amplification module includes a power splitter, multiple power amplification circuits, and a first combiner. The power splitter is coupled to each power amplification circuit and configured to perform power allocation on a first radio frequency signal and output a third radio frequency signal to each power amplification circuit, such that the sum of the powers of all third radio frequency signals output by the power splitter is equal to the power of the first radio frequency signal. Each power amplification circuit is coupled to the first combiner and configured to perform power amplification on the received third radio frequency signal and output a third radio frequency signal to the combiner. The combiner is coupled to a radio frequency isolation module and configured to synthesize the signals output separately by the multiple power amplification circuits to obtain a second radio frequency signal and output the second radio frequency signal to the radio frequency isolation module.

[0017] In such a design, multiple power amplification circuits are arranged within a power amplification module, and the signals output by the multiple power amplification circuits are combined into a single-path signal by using a first combiner for output. Thus, the power amplification module can output a single-path radio frequency signal with higher power, thereby improving the power of the radio frequency signal transmitted by the communication system. [Brief explanation of the drawing]

[0018] [Figure 1] This is a diagram illustrating an application scenario for a remote wireless unit. [Figure 2] This is a diagram showing the structure of the remote wireless unit. [Figure 3] This is a diagram showing the structure of a communication system according to one embodiment of the present application. [Figure 4] This is a diagram showing the specific structure of a power amplification module. [Figure 5] This is a diagram showing the structure of a radio frequency isolation module according to one embodiment of this application. [Figure 6A] This is a diagram of the structure of a divider circuit. [Figure 6B]It is a diagram of a specific structure of a splitting circuit. [Figure 6C] It is a diagram of a specific structure of another splitting circuit. [Figure 6D] It is a diagram of a specific structure of yet another splitting circuit. [Figure 7A] It is a diagram of a specific structure of a radio frequency isolation module according to an embodiment of the present application. [Figure 7B] It is a diagram of a specific structure of another radio frequency isolation module according to an embodiment of the present application. [Figure 8] It is a diagram of a structure of yet another radio frequency isolation module according to an embodiment of the present application. [Figure 9] It is a diagram of a structure of yet another radio frequency isolation module according to an embodiment of the present application. [Figure 10] It is a diagram of a structure of yet another radio frequency isolation module according to an embodiment of the present application. [Figure 11] It is a diagram of a structure of yet another radio frequency isolation module according to an embodiment of the present application. [Figure 12] It is a diagram of a structure of yet another radio frequency isolation module according to an embodiment of the present application.

Mode for Carrying Out the Invention

[0019] In the embodiment of the present application, "or" represents an association relationship between related objects and indicates that two relationships can exist. For example, A or B can represent the following cases. Only A exists, and only B exists, and A and B can be singular or plural.

[0020] In the present application, the term "connected" represents a connection relationship between two objects and can represent two connection relationships. For example, "A is connected to B" can represent the following cases. A is directly connected to B, and A is connected to B through C.

[0021] In the embodiments of this application, phrases such as “for example,” “in some embodiments,” and “in another embodiment” are used to indicate that an example, illustration, or explanation is being given. Any embodiment or design solution described as “example” in this application should not be described as being preferable to or having more advantages than another embodiment or design solution. More precisely, the use of the word “example” is intended to present a concept in a particular manner.

[0022] In embodiments of this application, “antenna” may include any preferred configuration, structure, and / or arrangement of one or more antenna elements, components, units, assemblies, and / or arrays. In some examples, the antenna may implement transmitting and receiving functions using separate transmitting and receiving antenna elements.

[0023] In embodiments of this application, the “power amplification module” may include any preferred configuration, structure, and / or arrangement of one or more power amplifiers, components, units, and assemblies.

[0024] In embodiments of this application, “transmitter” may include appropriate configurations for implementing transmitting functions, such as a digital signal processor, a digital-to-analog converter, a baseband filter, a radio frequency (RF) modulator, a filter, an RF separator, and a switch. In some examples, the “transmitter” may be a transceiver, which may implement transmitting and receiving functions separately. The transceiver may include appropriate configurations for implementing transmitting functions, such as a digital signal processor, a digital-to-analog converter, a baseband filter, a radio frequency (RF) modulator, a filter, an RF separator, and a switch. Alternatively, the transceiver may include appropriate configurations for implementing receiving functions, such as a combiner, a demodulator, a baseband filter, and an analog-to-digital converter.

[0025] In the embodiments of this application, “path” may be a transmission path, transmission channel, or transmission line. One “path” may refer to a transmission path, transmission channel, or transmission line. Multiple “paths” may refer to multiple transmission paths, transmission channels, or transmission lines. A signal on one “path” may refer to a signal transmitted through a transmission path, transmission channel, or transmission line. In some examples, “D” sending a signal on one path may mean that a signal sent by “D” is transmitted through a transmission path, transmission channel, or transmission line. “D” receiving a signal on one path may mean that “D” can receive a signal transmitted through a transmission path, transmission channel, or transmission line. “D” receiving signals on multiple paths may mean that “D” can receive a signal transmitted through multiple transmission paths, transmission lines, or transmission lines.

[0026] In the embodiments of this application, E corresponds one-to-one with F, meaning that one E corresponds to one F and one F corresponds to one E. Note that in the embodiments of this application, terms such as “first” and “second” are not used for the purpose of distinguishing descriptions and should not be understood as an indication or suggestion of relative importance or sequence.

[0027] The radio frequency isolation module provided in the embodiments of this application may be applied to a number of communication systems, including global system for mobile communications (GSM), code division multiple access (CDMA) systems, wideband code division multiple access (WCDMA) systems, general packet radio service (GPRS), long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, universal mobile telecommunications system (UMTS), worldwide interoperability for microwave access (WiMAX) communication systems, or 5th-generation (5G) mobile communication technologies. It should be noted that the specific communication systems are not limited to those described in the embodiments of this application.

[0028] In embodiments of this application, “frequency band” can be a frequency band that is divided into divided frequency bands and / or future versions of frequency bands. For example, “frequency band” can be a frequency band divided according to an existing cellular specification and / or protocol (e.g., the 3rd generation partnership project (3GPP) protocol or the LTE protocol), or a frequency band divided according to a future version of the cellular specification and / or protocol, or a frequency band divided according to the Wireless Fidelity (Wi-Fi) protocol in a wireless local area network, or a frequency band divided according to the Bluetooth protocol.

[0029] Figure 1 is a diagram of a communication system architecture to which one embodiment of the present application may be applied. As shown in Figure 1, the communication system architecture may include a baseband processing unit and a remote radio unit (RRU). The baseband processing unit may be located in an equipment room, and the RRU may be located near an antenna, for example, on a communication tower where the antenna is located. The baseband processing unit, RRU, and antenna shown in Figure 1 are used only as an example to illustrate the communication system architecture and do not indicate the number of antennas and RRUs in the communication system. In general, the communication system may be implemented as a base station. The base station may include a base station processing unit, at least one antenna, and at least one RRU. The baseband processing unit may be connected to at least one RRU.

[0030] Existing RRUs support single-band radio frequency signals. To enable a communication system to support radio frequency signals of multiple frequency bands, at least two RRUs may be arranged in the communication system, and at least two RRUs occupy a larger space. Alternatively, at least two power amplification modules supporting different frequency bands may be arranged in a single RRU, and thus the single RRU occupies more space. Alternatively, a power amplification module supporting multiple frequency bands may be arranged in a single RRU, and it has higher power. Figure 2 is a diagram of the structure of an RRU that supports multiple frequency bands. The RRU includes a transmitter (TX), a power amplification circuit, a radio frequency isolation module, and a filter. The transmitter may have the ability to provide a multiband signal. The signal provided by the transmitter may include multiple frequency bands. For example, the signal provided by the transmitter includes signals in a first frequency band and a second frequency band. The power amplification circuit in the RRU supports performing power amplification on the multiband signal and can output the multiband signal to the isolator. The function of an isolator is generally to transmit a power-amplified signal to a filter and isolate the reflected signal generated in the filter or antenna, preventing the reflected signal from affecting the power amplification circuit.

[0031] In some scenarios, the first and second frequency bands can be any two of the 1.8 GHz, 2.1 GHz, or 2.6 GHz frequency bands. Accordingly, the isolator in the RRU must be one with an operating frequency band of 1805 MHz to 2690 MHz. An isolator capable of supporting multiple frequency bands in this way is sometimes called an ultra-wideband isolator.

[0032] The performance parameters of an isolator in a communication system generally include insertion loss and intermodulation distortion. The insertion loss of an isolator generally refers to the signal loss generated when the isolator is inserted into the communication system and can be understood as signal attenuation. When two or more signals with different frequencies are applied to the same nonlinear circuit, the signals are modulated to each other to produce a signal with a new frequency. If the new frequency falls precisely within the bandwidth of the channel on which the receiver operates, interference occurs to the receiver. This interference is generally called intermodulation distortion. Intermodulation distortion in a communication system also affects the quality of the signal transmitted by the transmitter. The insertion loss of an isolator with an operating frequency bandwidth of 1805 MHz to 2690 MHz is generally greater than 0.5 dB. An isolator has a maximum power parameter, which represents the maximum power at which the signal can be transmitted. As the power of the signal transmitted by the isolator decreases, the intermodulation distortion of the isolator decreases. When the power of the signal transmitted by the isolator in the 1805MHz to 2690MHz frequency band is the maximum power parameter, the intermodulation distortion of the isolator is generally greater than -60dBc. However, existing communication systems require that the intermodulation distortion be generally less than -70dBc. In existing communication systems, the power of the signal transmitted by the isolator in the 1805MHz to 2690MHz frequency band must be less than the maximum power parameter of the isolator, meaning that the isolator cannot operate at full power in the 1805MHz to 2690MHz frequency band.

[0033] To reduce the insertion loss of an RRU and improve the intermodulation distortion of an RRU, one embodiment of this application provides a radio frequency isolation module that can support the output of multiband signals and has isolation capabilities to prevent reflected signals from affecting power amplification circuits or power amplification modules. The radio frequency isolation module has lower insertion loss and reduces intermodulation distortion. It should be noted that the embodiments of this application may be applied to RRUs, and further to units in communication systems, for example, to an active antenna unit (AAU). Example application scenarios of the radio frequency isolation module are not limited in this application. One embodiment of this application further provides a communication system, which may include the radio frequency isolation module provided in this application. The following gives a detailed description relating to the accompanying drawings. It should be noted that the specific frequency bands described in this application are used only as examples for illustrative purposes and are not to be used as specific limitations on the frequency bands applicable to the radio frequency isolation module provided in this application.

[0034] Figure 3 is a diagram of the structure of a communication system according to one embodiment of the present application. The communication system 10 may include a transmitter 100, a power amplification module 101, and a radio frequency isolation module 102, as provided in the embodiment of the present application. The transmitter 100, the power amplification module 101, and the radio frequency isolation module 102 are coupled in sequence. In this embodiment of the present application, all signals processed by the modules in the communication system 10 are radio frequency signals, which are briefly shown below as signals.

[0035] Transmitter 100 is connected to the input side of power amplifier module 101, and transmitter 100 may output a signal in one path, the signal including at least one frequency band signal. The operating frequency band of transmitter 100 includes at least one frequency band. Transmitter 100 may have the ability to output a signal in at least one frequency band. For example, transmitter may have the ability to output a signal in a first frequency band, and the signal in one path output by transmitter 100 may include a signal in the first frequency band. In another example, transmitter may have the ability to output a signal in a first frequency band or may have the ability to output a signal in a second frequency band. The signal in a path output by transmitter 100 may include a signal in the first frequency band, or the signal in a path output by transmitter 100 may include a signal in the second frequency band, or the signal in a path output by transmitter 100 may include a signal in the first frequency band and a signal in the second frequency band.

[0036] In the communication system 10, the operating frequency band of the power amplification module 101 may include or cover the operating frequency band of the transmitter 100. The frequency band into which the signal output by the power amplification module 101 enters is the same as the frequency band into which the signal received by the power amplification module 101 enters; that is, the power amplification module 101 does not change the frequency band of the signal. The power amplification module 101 can amplify signals in at least one frequency band provided by the transmitter 100. For example, if the signal in one path provided by the transmitter 100 includes a signal in a first frequency band, the power amplification module 101 can amplify the signal in the first frequency band. In another example, if the signal in one path provided by the transmitter 100 includes a signal in a first frequency band and a signal in a second frequency band, the power amplification module 101 can amplify the signal in the first frequency band and the signal in the second frequency band.

[0037] The operating frequency band of the radio frequency isolation module 102 may include or cover the operating frequency band supported by the power amplifier module 101. Since the operating frequency band of the power amplifier module 101 includes or covers the operating frequency band of the transmitter 100, it can be seen that the operating frequency band supported by the radio frequency isolation module 102 also includes or covers the operating frequency band of the transmitter 100. The radio frequency isolation module 102 has signal transmission capability and isolation capability. The radio frequency isolation module 102 provided in this embodiment of the present application can support high-power signal transmission and has lower insertion loss and lower intermodulation distortion. The radio frequency isolation module 102 can isolate the signal at antenna 103 from the power amplifier module 101, thereby preventing the signal at antenna 103 from being transmitted to the power amplifier module 101, and thereby protecting the power amplifier module 101.

[0038] For example, the power amplification module 101 may include a power splitter 101A, a plurality of power amplification circuits, and a first combiner 101B. Figure 4 is a diagram of a specific structure of a power amplification module according to an exemplary embodiment. The power amplification module 101 may include a power splitter 101A, d power amplification circuits, and a first combiner 101B, where d is an integer greater than 1.

[0039] The input side of the power splitter 101A may include one first input terminal, and the output side of the power splitter 101A may include d first output terminals. The d first output terminals of the power splitter 101A correspond one-to-one with d power amplifier circuits. One first output terminal corresponds to one power amplifier circuit, and one power amplifier circuit corresponds to one first output terminal. The power splitter 101A can split a signal from one path received by the first input terminal into d signals and output d signals to the power amplifier circuits corresponding to the first output terminals by using the d first output terminals. The operating frequency band of the power amplifier module 101 may include one or more frequency bands. The operating frequency band of each power amplifier circuit may be the same as the operating frequency band of the power amplifier module 101. In the d power amplifier circuits of the power amplifier module 101, each power amplifier circuit can amplify the received signal.

[0040] The input side of the first combiner 101B may include d second input terminals, and the output side of the first combiner 101B may include one second output terminal. The d second input terminals may correspond one-to-one with d power amplifier circuits, one second input terminal corresponds to one power amplifier circuit, and one power amplifier circuit corresponds to one second input terminal. The power amplifier circuits output amplified signals to their corresponding second input terminals. The first combiner 101B may combine the signals received by the second input terminals and output a combined signal using its second output terminal. For example, the combined signal is output to the radio frequency isolation module 102. The power amplifier module 101 in the communication system 10 may output a signal through one path to the radio frequency isolation module 102.

[0041] The power amplification module 101 in the communication system 10 provided in this embodiment of the present application can output higher power. The radio frequency isolation module 102 provided in this embodiment of the present application can support the transmission of signals with higher power. The radio frequency isolation module 102 provided in this embodiment of the present application will be described below.

[0042] Figure 5 shows a radio frequency isolation module according to one embodiment of the present application. The radio frequency isolation module 102 may be coupled to a power amplification module 101. Optionally, the power amplification module 101 may have the structure shown in Figure 4. Alternatively, the power amplification module 101 may use a different structure. This is not particularly limited to this embodiment of the present application.

[0043] The radio frequency isolation module 102 may include a splitting circuit 201, an isolation circuit 202, and a combining circuit 203. The isolation circuit 202 may include at least one isolation branch.

[0044] The splitter circuit 201 may include an input terminal and N output terminals, the input terminal being coupled to the power amplification module 101 to receive a target radio frequency signal. The target radio frequency signal may include signals in S frequency bands, where S is an integer less than or equal to N. The N output terminals correspond one-to-one with the N frequency bands, one output terminal is coupled to one of the isolation branches, and each output terminal is configured to output a signal in the frequency band corresponding to the coupled isolation branch. The splitter circuit 201 may be configured to split the target radio frequency signal into signals in each of the S frequency bands and output signals using the output terminals corresponding to each frequency band.

[0045] Each isolation branch may be connected to the combining circuit 203, and each isolation branch may be configured to transmit a signal given by one of the output terminals of the splitter connected to the combining circuit 203, preventing the signal generated in the combining circuit 203 from being transmitted to the input terminal connected to the isolation branch.

[0046] The combining circuit 203 is coupled to the antenna 103 and is configured to combine the signals transmitted by the isolation branch in the isolation circuit 202 and output the combined signal to the antenna 103.

[0047] First, the splitter circuit 201 will be described. The splitter circuit 201 may have inter-frequency splitting capability. When a signal in one path received by the splitter circuit 201 contains signals in multiple frequency bands, the splitter circuit 202 may split the signal in one path into signals in multiple paths, each of which contains a signal in a single frequency band obtained through the split. That is, the splitter circuit 201 may split a signal in one path containing signals in multiple frequency bands for output into signals in multiple paths containing signals in a single frequency band.

[0048] In one example, a signal from one path received by the splitter circuit 201 includes a signal in a first frequency band and a signal in a second frequency band. The splitter circuit 201 may split the received signal into two signal paths. The two signal paths obtained through the splitter are shown as the signal from the first path and the signal from the second path, respectively. The signal from the first path includes a signal in the first frequency band, and the signal from the second path includes a signal in the second frequency band. In another example, a signal from one path received by the splitter circuit 201 includes a signal in the first frequency band, a signal in the second frequency band, and a signal in the third frequency band. The splitter circuit 201 may split the received signal into three signal paths. In the three signals obtained through the splitter, the signal from the first path includes a signal in the first frequency band, the signal from the second path includes a signal in the second frequency band, and the signal from the third path includes a signal in the third frequency band. In a possible scenario, when the signal from one path received by the splitter circuit 201 includes a signal of one frequency band, the splitter circuit 201 may output the signal from the received path.

[0049] The input side of the splitter circuit 201 is coupled to the power amplifier module 101. The input side of the splitter circuit 201 has one input terminal. The input terminal of the splitter circuit 201 may be configured to receive a signal on one path provided by the power amplifier module 101. For example, the input terminal of the splitter circuit 201 may receive a signal provided by the power amplifier module 101. The signal provided by the power amplifier module 101 may include signals of at least one frequency band.

[0050] The output side of the splitter circuit 201 is coupled to the isolation circuit 202. The output side of the splitter circuit 201 includes multiple output terminals. The operating frequency band of the splitter circuit 201 includes N frequency bands, and the output side of the splitter circuit 201 includes N output terminals, where N is an integer greater than 1. The N output terminals correspond one-to-one with the N frequency bands, with one output terminal corresponding to one frequency band and one frequency band corresponding to one output terminal. Each of the N output terminals is configured to output a signal through one path, and the output signal through one path includes a signal in the frequency band corresponding to the output terminal. The multiple output terminals of the splitter circuit 201 are each connected to the isolation circuit 202.

[0051] Figure 6A shows the structure of a splitter circuit according to an exemplary embodiment. The input side of the splitter circuit 201 may have one input terminal Z1. The output side of the splitter circuit 201 may have N output terminals P, each output terminal outputting a signal for one path. In this case, the N output terminals output signals for N paths. N can be an integer greater than or equal to X. For ease of explanation, the i-th output terminal of the N output terminals is denoted as output terminal Pi, where i can be a value from 1 to N, and the frequency band corresponding to output terminal Pi is denoted as frequency band mi.

[0052] For example, in a scenario where the splitter circuit 201 has three output terminals and the splitter circuit 201 has the capability to perform inter-frequency division processing for three frequency bands, that is, when X is 3 and N is 3, the frequency band corresponding to output terminal P1 is frequency band m1, the frequency band corresponding to output terminal P2 is frequency band m2, and the frequency band corresponding to output terminal P3 is frequency band m3.

[0053] The above functions of the splitter circuit 201 can be implemented by using one or more splitters. In one example, the splitter circuit 201 may include one splitter. As shown in Figure 6B, the splitter circuit 201 may include a first splitter. The input side of the first splitter has one input terminal, and the output side has N output terminals, and the N output terminals of the first splitter can be implemented as the N output terminals of the splitter circuit 201.

[0054] In another example, the splitter circuit 201 may include multiple splitters. In a multiple splitter, each splitter may have multiple output terminals. As shown in Figure 6C, the multiple splitters may include a second splitter and at least one third splitter. The input terminal of the second splitter is the input terminal of the splitter circuit 201, and the second splitter has multiple output terminals. Some output terminals may be used as output terminals of the splitter circuit 201, and other output terminals are coupled to the input terminals of at least one third splitter. All output terminals of at least one third splitter are also used as output terminals of the splitter circuit 201.

[0055] As shown in Figure 6D, the multiple splitters may include a second splitter and multiple third splitters. The input terminals of the second splitter are the input terminals of the splitter circuit 201, and the second splitter has multiple output terminals, the multiple output terminals of the second splitter correspond one-to-one with the multiple third splitters, and one output terminal of the second splitter is coupled to the input terminal of the corresponding third splitter. All output terminals of the multiple third splitters are used as output terminals of the splitter circuit 201.

[0056] In the above example, the specific structure of the split circuit 201 shown in Figures 6B to 6D is used only as an example for illustrative purposes and is not limited thereto.

[0057] The operating frequency band of the radio frequency isolation module 102 provided in the embodiments of this application includes N frequency bands. In other words, the radio frequency isolation module 102 may support N frequency bands. The operating frequency band of the splitter circuit 201 may cover or include the operating frequency band of the radio frequency isolation module 102.

[0058] In one possible scenario, the operating frequency bandwidth of the radio frequency isolation module 102 is the same as the operating frequency bandwidth of the splitter circuit 201. In another possible scenario, the operating frequency bandwidth of the splitter circuit 201 covers the operating frequency bandwidth of the radio frequency isolation module 102, and the range of the operating frequency bandwidth of the splitter circuit 201 is greater than the range of the operating frequency bandwidth of the radio frequency isolation module 102. For example, the operating frequency bandwidth of the radio frequency isolation module 102 includes N frequency bands, and the output side of the splitter circuit 102 includes X output terminals, and the X output terminals may include the above N output terminals. In this case, X is greater than N. That is, the X frequency bands supported by the splitter circuit 102 include the N frequency bands supported by the radio frequency isolation module 102. In this case, the N output terminals of the X output terminals of the splitter circuit 201 may correspond one-to-one with the N frequency bands supported by the radio frequency isolation module 102.

[0059] Please refer to Figure 5. The isolation circuit 202 is coupled to the input side of the combining circuit 203, and the isolation circuit 202 may have the ability to transmit signals unidirectionally. The isolation circuit 202 can transmit signals from at least one path given by the splitter circuit 201 to the combining circuit 203 and isolate the signals generated in the combining circuit 203 from the splitter circuit 201. Since the signals from one path output by the splitter circuit 201 contain signals of only one frequency band, and different output ends output signals of different frequency bands, the isolation circuit 202 transmits signals from at least one path given by the splitter circuit 201 to the combining circuit 203, and the isolation circuit 202 transmits signals of at least one frequency band to the combining circuit 203.

[0060] The output side of the combining circuit 203 is coupled to the antenna 103, and the combining circuit 203 may have filtering and inter-frequency combining functions. The combining circuit 203 combines signals from multiple paths of different frequency bands on the input side of the splitting circuit 201 into a signal of one path and outputs the signal of that path to the antenna 103. Alternatively, the combining circuit 203 may be configured to perform inter-frequency combining on signals from multiple paths transmitted by the isolation circuit 202 and output a signal of one path to the antenna 103. The signal of the path output to the antenna 103 by the combining circuit 203 includes signals from at least two frequency bands.

[0061] Referring to Figure 6A, assume that at the N output terminals of the splitter circuit 201, output terminal P1 corresponds to a first frequency band and output terminal P2 corresponds to a second frequency band. In one example, the signal in one path provided to the splitter circuit 201 by the power amplification module 101 includes a signal in the first frequency band and a signal in the second frequency band. After inter-frequency splitting is performed on the signal that can be received by the splitter circuit 201, the signal in the first frequency band is output using output terminal P1, and the signal in the second band is output using output terminal P2. The isolation circuit 202 can transmit the signal in the first frequency band provided by output terminal P1 and the signal in the second frequency band provided by output terminal P2 to the combining circuit 203. The combining circuit 203 combines the signal of the first frequency band provided by output terminal P1 and the signal of the second frequency band provided by output terminal P2, that is, it combines the signals from the two paths into a signal of one path and provides the combined signal to antenna 103. In this case, the single-path signal output to the antenna by the combining circuit 203 includes the signal of the first frequency band and the signal of the second frequency band.

[0062] The operating frequency bandwidth of isolation circuit 202 may be the same as that of radio frequency isolation module 102, or the operating frequency bandwidth of isolation circuit 202 may cover the operating frequency bandwidth of radio frequency isolation module 102. In a possible design, the output side of splitter circuit 201 has N output terminals, and isolation circuit 202 contains N isolation branches. In other words, the number of isolation branches in isolation circuit 202 is the same as the number of output terminals of splitter circuit 201. The number of isolation branches in isolation circuit 202 is the same as the number of input terminals of combining circuit 203. The following provides a separate explanation using examples.

[0063] In a possible design, Figure 7A is an example diagram of a specific structure of the radio frequency isolation module. The radio frequency isolation module 102 may be coupled to the power amplification module 101. Optionally, the power amplification module 101 may have the structure shown in Figure 4. Alternatively, the power amplification module 101 may use a different structure. This is not particularly limited in this embodiment of the present application.

[0064] In the radio frequency isolation module 102, the splitter circuit 201 has N output terminals, and the isolation circuit 202 may include N isolation branches. The N isolation branches may correspond one-to-one with the N output terminals P of the splitter circuit 201. One isolation branch corresponds to one output terminal, one output terminal corresponds to one isolation branch, and the isolation branch is coupled to the output terminal P corresponding to the isolation branch. For ease of explanation, the isolation branch corresponding to an output terminal Pi is denoted as isolation branch Qi, where i can be a value from 1 to N. The operating frequency band of isolation branch Qi may include the frequency band corresponding to output terminal Pi. For example, the frequency band corresponding to output terminal P1 is frequency band m1, and the operating frequency band of isolation branch Q1 includes or covers frequency band m1. In some examples, the operating frequency band of isolation branch Qi is the same as the frequency band corresponding to output terminal Pi. In some other examples, the operating frequency band of the isolation branch Qi may include the frequency band corresponding to the output terminal Pi, or the operating frequency band of the isolation branch Qi may cover the frequency band corresponding to the output terminal Pi.

[0065] The input side of the combining circuit 203 may have N input terminals, and the N input terminals correspond one-to-one with N isolation branches. One isolation branch corresponds to one input terminal, one input terminal corresponds to one isolation branch, and the isolation branches are coupled to their corresponding input terminals. For ease of explanation, the i-th input terminal of the N input terminals of the combining circuit 203 is denoted as input terminal Ki.

[0066] The signal output from the output terminal Pi of the splitter circuit 201 can be transmitted to the input terminal Ki of the combining circuit 203 through the isolation branch Qi. The output terminals of the splitter circuit 201 are transmitted to the combining circuit 203 by using one path of the isolation branch, and it can be seen that any isolation branch Qi can isolate the reflected signal generated in the combining circuit 203, preventing the reflected signal from affecting the power amplification module 101. Any isolation branch Qi may include an isolator or circulator. Such a design can reduce the requirement of the isolation branch Qi for the operating frequency bandwidth range, and an isolator or circulator with a smaller operating frequency bandwidth range may be used to reduce the insertion loss and intermodulation distortion range of the radio frequency isolation module 102. The intermodulation distortion generated by an isolator or circulator with a small operating frequency bandwidth range when the transmitted signal power is at maximum power can satisfy the communication system's requirements for intermodulation distortion. An isolator or circulator with a small operating frequency band range can operate at full power, and therefore the radio frequency isolation module 102 can support higher power.

[0067] In some scenarios, the combining circuit 203 may include a multiband combiner, with the first side of the multiband combiner coupled to the input terminals of the combining circuit 203, and the second side of the multiband combiner coupled to the antenna 103.

[0068] In some other scenarios, the combining circuit 203 may include a multiband combiner and at least one filter. At least one filter may correspond one-to-one with at least one input terminal of the combining circuit 203. In other words, at least one filter in the combining circuit 203 may correspond one-to-one with at least one isolation branch in the isolation circuit 202. The input terminal of each filter may be coupled to a corresponding input terminal, or the input terminal of each filter may be used as an input terminal of the combining circuit 203 and coupled to a corresponding isolation branch. The output terminal of each filter is coupled to the multiband combiner. Each filter may have a filtering function, for example, to filter out noise signals. The operating frequency bandwidth of each filter may be the same as the operating frequency bandwidth of the coupled isolation branch. Each filter may perform filtering on the signal given by the coupled isolation branch and then output the signal to the multiband combiner. In possible cases, multiple filters may supply signals to the multiband combiner. A multiband combiner may perform inter-frequency synthesis on signals given by multiple filters and then output a signal through a single path. This signal path is sent to antenna 103 for transmission. In another possible case, one filter may provide a signal to the multiband combiner, which may also output the filtered signal to antenna 103 for transmission.

[0069] In possible implementations, based on the structure of the radio frequency isolation module 102 shown in Figure 7A, the radio frequency isolation module 102 may further include N functional circuits, as shown in Figure 7B, where the N isolation branches in the isolation circuit 202 correspond one-to-one with the N functional circuits. The functional circuit corresponding to an isolation branch Qi may be denoted as functional circuit Wi, where i can be a value from 1 to N. The isolation branch Qi is coupled to the input terminal Ki of the combining circuit 203 by using functional circuit Wi. In one example, the functional circuit Qi may be configured to perform impedance matching with respect to the signal transmitted by the isolation branch Qi.

[0070] In one example, Figure 8 shows a diagram of a specific structure of the radio frequency isolation module 102. The radio frequency isolation module 102 may be coupled to a power amplification module 101. Optionally, the power amplification module 101 may have the structure shown in Figure 4. Alternatively, the power amplification module 101 may use a different structure. This is not particularly limited in this embodiment of the present application.

[0071] The operating frequency band of the radio frequency isolation module 102 may include two frequency bands, which are referred to as the first frequency band and the second frequency band, respectively. The splitter circuit 201 may include two output terminals. Output terminal P1 corresponds to the first frequency band, and output terminal P2 corresponds to the second frequency band. The isolation circuit 202 may include two isolation branches, which are isolation branch Q1 and isolation branch Q2, respectively. Isolation branch Q1 is coupled to output terminal P1, and isolation branch Q2 is coupled to output terminal P2. The combining circuit 203 has two input terminals, which are input terminal K1 and input terminal K2, respectively. Input terminal K1 is coupled to isolation branch Q1, and input terminal K2 is coupled to isolation branch Q2.

[0072] The splitter circuit 201 can perform inter-frequency division processing on the received signal. If the signal received by the splitter circuit 201 includes a signal in a first frequency band, the splitter circuit 201 can output a signal in the first frequency band by using output terminal P1. If the signal received by the splitter circuit 201 includes a signal in a second frequency band, the splitter circuit 201 can output a signal in the second frequency band by using output terminal P2. If the signal received by the splitter circuit 201 includes both a signal in the first frequency band and a signal in the second frequency band, after performing inter-frequency division processing on the received signal, the splitter circuit 201 outputs a signal in the first frequency band by using output terminal P1 and outputs a signal in the second frequency band by using output terminal P2.

[0073] Isolation branch Q1 can transmit a signal in a first frequency band provided by output terminal P1 to input terminal K1 of the combining module, preventing reflected signals generated in the combining circuit 203 from being transmitted to output terminal P1. Isolation branch Q2 can transmit a signal in a second frequency band provided by output terminal P2 to input terminal K2 of the combining circuit 203, preventing reflected signals generated in the combining circuit 203 from being transmitted to output terminal P2. The combining circuit 203 can perform interfrequency combining on the signals in the first frequency band and the signals in the second frequency band provided by isolation branches Q1 and Q2, respectively, to combine the signals into a signal in a single path, and output the combined signal to antenna 103.

[0074] In the above embodiment, the first frequency band may be a frequency band from 758 MHz to 960 MHz, and the second frequency band may be a frequency band of 1.8 GHz. Alternatively, the first frequency band may be a frequency band from 758 MHz to 960 MHz, and the second frequency band may be a frequency band of 2.1 GHz. Alternatively, the first frequency band may be a frequency band from 758 MHz to 960 MHz, and the second frequency band may be a frequency band of 2.6 GHz. Alternatively, the first frequency band may be a frequency band of 1.8 GHz, and the second frequency band may be a frequency band of 2.1 GHz. Alternatively, the first frequency band may be a frequency band of 1.8 GHz, and the second frequency band may be a frequency band of 2.6 GHz. Alternatively, the first frequency band may be a frequency band of 2.6 GHz, and the second frequency band may be a frequency band of 2.1 GHz.

[0075] In another example, Figure 9 shows a diagram of a specific structure of a radio frequency isolation module. The radio frequency isolation module 102 may be coupled to a power amplification module 101. Optionally, the power amplification module 101 may have the structure shown in Figure 4. Alternatively, the power amplification module 101 may use a different structure. This is not particularly limited to this embodiment of the present application.

[0076] The radio frequency isolation module 102 may support three frequency bands, which are referred to as the first frequency band, the second frequency band, and the third frequency band, respectively. The splitter circuit 201 may include three output terminals. Output terminal P1 corresponds to the first frequency band, output terminal P2 corresponds to the second frequency band, and output terminal P3 corresponds to the third frequency band.

[0077] The isolation circuit 202 may include three isolation branches. Isolation branch Q1 is coupled to output terminal P1, isolation branch Q2 is coupled to output terminal P2, and isolation branch Q3 is coupled to output terminal P3. The combining circuit 203 has three input terminals. Input terminal K1 is coupled to isolation branch Q1, input terminal K2 is coupled to isolation branch Q2, and output terminal K3 is coupled to isolation branch Q3.

[0078] The splitter circuit 201 can perform inter-frequency division processing on the received signal. If the signal received by the splitter circuit 201 includes a signal in a first frequency band, the splitter circuit 201 can output a signal in the first frequency band by using output terminal P1. If the signal received by the splitter circuit 201 includes a signal in a second frequency band, the splitter circuit 201 can output a signal in the second frequency band by using output terminal P2. If the signal received by the splitter circuit 201 includes a signal in a third frequency band, the splitter circuit 201 can output a signal in the third frequency band by using output terminal P3. If the signal received by the splitter circuit 201 includes both a signal in the first frequency band and a signal in the second frequency band, after performing inter-frequency division processing on the received signal, the splitter circuit 201 outputs a signal in the first frequency band by using output terminal P1 and outputs a signal in the second frequency band by using output terminal P2. If the signal received by the splitter circuit 201 includes a signal in a first frequency band and a signal in a third frequency band, after performing inter-frequency splitting on the received signal, the splitter circuit 201 outputs the signal in the first frequency band using output terminal P1 and outputs the signal in the third frequency band using output terminal P3. If the signal received by the splitter circuit 201 includes a signal in a second frequency band and a signal in a third frequency band, after performing inter-frequency splitting on the received signal, the splitter circuit 201 outputs the signal in the second frequency band using output terminal P2 and outputs the signal in the third frequency band using output terminal P3. If the signal received by the splitter circuit 201 includes a signal in a first frequency band, a signal in a second frequency band, and a signal in a third frequency band, the splitter circuit 201 performs inter-frequency splitting on the received signal, and then outputs the signal in the first frequency band using output terminal P1, the signal in the second frequency band using output terminal P2, and the signal in the third frequency band using output terminal P3.

[0079] Isolation branch Q1 can transmit a signal of a first frequency band to the input terminal K1 of the combining circuit 203, preventing the reflected signal generated in the combining circuit 203 from being transmitted to the output terminal P1. Isolation branch Q2 can transmit a signal of a second frequency band to the input terminal K2 of the combining circuit 203, preventing the reflected signal generated in the combining circuit 203 from being transmitted to the output terminal P2. Isolation branch Q3 can transmit a signal of a third frequency band to the input terminal K3 of the combining circuit 203, preventing the reflected signal generated in the combining circuit 203 from being transmitted to the output terminal P3. The combining circuit 203 can perform interfrequency synthesis on the signals of the first, second, and third frequency bands given by isolation branches Q1, Q2, and Q3, respectively, and after synthesizing the signals into a signal on a single path, it can output the synthesized signal to the antenna.

[0080] In the above embodiment, the first frequency band may be a frequency band from 758 MHz to 960 MHz, the second frequency band may be a frequency band of 1.8 GHz, and the third frequency band may be a frequency band of 2.1 GHz. Alternatively, the first frequency band may be a frequency band from 758 MHz to 960 MHz, the second frequency band may be a frequency band of 2.1 GHz, and the third frequency band may be a frequency band of 2.6 GHz. Alternatively, the first frequency band may be a frequency band from 758 MHz to 960 MHz, the second frequency band may be a frequency band of 2.6 GHz, and the third frequency band may be a frequency band of 1.8 GHz. Alternatively, the first frequency band may be a frequency band of 1.8 GHz, the second frequency band may be a frequency band of 2.1 GHz, and the third frequency band may be a frequency band of 2.6 GHz.

[0081] In another possible implementation, the amount of output terminals in the splitter circuit 201 may be greater than the amount of isolation branches in the isolation circuit 202, and the amount of isolation branches in the isolation circuit 202 may be the same as the amount of input terminals in the combiner circuit 203. The following provides a separate explanation using an example. In this implementation, the isolation circuit 202 may contain M isolation branches, where M is an integer less than N.

[0082] In a possible design, Figure 10 is an example diagram of a specific structure of the radio frequency isolation module. The radio frequency isolation module 102 may be coupled to the power amplification module 101. Optionally, the power amplification module 101 may have the structure shown in Figure 4. Alternatively, the power amplification module 101 may use a different structure. This is not particularly limited in this embodiment of the present application. For details of the splitter circuit 201 in the radio frequency isolation module, please refer to the relevant description of the splitter circuit 201 shown in Figure 4. Details are not described again here.

[0083] In the isolation circuit 202 of the radio frequency isolation module 102, the M isolation branches are M first isolation branches, which are denoted as first isolation branch Mr-1, first isolation branch Mr-2, ..., first isolation branch Mr-M, respectively. For details on the divider circuit 201 in the radio frequency isolation module, please refer to the relevant description of the divider circuit 201 shown in Figure 6A. Details will not be explained again here.

[0084] One output terminal of the splitter circuit 201 is coupled to exactly one of the M first isolation branches. In the M first isolation branches, the input side of any first isolation branch Mr may be coupled to multiple output terminals of the splitter circuit 201, or any first isolation branch Mr may be coupled to at least two output terminals of the splitter circuit 201, and the first isolation branch Mr may receive signals given by at least two output terminals. The output side of any first isolation branch Mr may be coupled to the input terminal of the combining circuit 203.

[0085] For example, the first isolation branch Mr-1 is coupled to the output terminals P1 and P2 of the splitter circuit 201 and to the input terminal K1 of the combiner circuit 203. The operating frequency band of the first isolation branch Mr-1 may include the frequency band corresponding to output terminal P1 and the frequency band corresponding to output terminal P2. The first isolation branch Mr-1 can transmit the signals given by output terminals P1 and P2 to the input terminal K1 of the combiner circuit 203, thereby preventing the reflected signals generated in the combiner circuit 203 from being transmitted to the output terminals P1 and P2 of the splitter circuit 201.

[0086] Similarly, the first isolation branch Mr-2 is coupled to the output terminals P3 and P4 of the splitter circuit 201 and to the input terminal K2 of the combiner circuit 203. The operating frequency band of the first isolation branch Mr-2 may include the frequency band corresponding to the output terminal P3 and the frequency band corresponding to the output terminal P4. The first isolation branch Mr-2 transmits the signals given by the output terminals P3 and P4 to the input terminal K2 of the combiner circuit 203, and can prevent reflected signals generated in the combiner circuit 203 or antenna 103 from being transmitted to the output terminals P3 and P4 of the splitter circuit 201.

[0087] It should be noted that in some scenarios, the amount of the output terminals of the splitter circuit 201 coupled to the first isolation branch may be the same. For example, in the example above, both the first isolation branch Mr-1 and the first isolation branch Mr-2 are connected to two input terminals. In other words, the amount of frequency band covered by the operating frequency bands of the first isolation branches may be the same. The first isolation branch Mr-1 covers two frequency bands, which are the frequency band corresponding to output terminal P1 and the frequency band corresponding to output terminal P2, respectively. The first isolation branch Mr-2 covers two frequency bands, which are the frequency band corresponding to output terminal P3 and the frequency band corresponding to output terminal P4, respectively.

[0088] In some other scenarios, the amount of output terminals connected to the first isolation branch may differ, or the amount of frequency band covered by the operating frequency band of the first isolation branch may differ. This is not limited to the embodiments of this application.

[0089] In another possible design, the M isolation branches include at least one first isolation branch Mr and at least one second isolation branch Ms. One output end of the splitter circuit 201 is coupled to only one isolation branch among the M isolation branches, or one output end of the splitter circuit 201 is coupled to one first isolation branch or one second isolation branch.

[0090] In this design, the input side of any first isolation branch Mr among the M isolation branches may be coupled to multiple output terminals of the splitter circuit 201, or the first isolation branch Mr may be coupled to at least two output terminals of the splitter circuit 201, and the first isolation branch Mr may receive signals given by at least two output terminals. The output side of any first isolation branch Mr is coupled to one input terminal of the combining circuit 203. Optionally, the output terminal of any first isolation branch Mr may be coupled to one input terminal of the combining circuit 203 by using a functional circuit, and the functional circuit coupled to the output terminal of the first isolation branch Mr may be configured to perform impedance matching with respect to the signal given by the output terminal of the first isolation branch Mr.

[0091] The input side of any second isolation branch Ms among the M isolation branches may be coupled to one output terminal of the splitter circuit 201, and the second isolation branch Ms may receive a signal given by its output terminal. The output side of the second isolation branch Ms is coupled to one input terminal of the combiner circuit 203. Optionally, the output terminal of any second isolation branch Ms may be coupled to one input terminal of the combiner circuit 203 by using a functional circuit, and the functional circuit coupled to the output terminal of the second isolation branch Ms may be configured to perform impedance matching with respect to the signal given by the output terminal of the second isolation branch Ms.

[0092] In such a design, among M isolation branches, the first isolation branch may include an isolator or circulator, and the second isolation branch may include an isolator or circulator. The amount of frequency band covered by the operating frequency band of the first isolation branch may be greater than or equal to the amount of frequency band covered by the operating frequency band of the second isolation branch.

[0093] Figure 11 is an example diagram of a specific structure of a radio frequency isolation module. The radio frequency isolation module 102 may be coupled to a power amplification module 101. Optionally, the power amplification module 101 may have the structure shown in Figure 4. Alternatively, the power amplification module 101 may use a different structure. This is not particularly limited in this embodiment of the present application. For details of the splitter circuit 201 in the radio frequency isolation module, please refer to the relevant description of the splitter circuit 201 shown in Figure 4. Details are not described again here.

[0094] The isolation circuit 202 contains M isolation branches. The M isolation branches may contain z first isolation branches Mr and x second isolation branches Ms, where z is an integer greater than or equal to 1, x is an integer greater than or equal to 1, and the sum of z and x is M. Figure 11 shows an example where z is 2, but note that this is not used as a specific limitation on the value of z.

[0095] For example, still refer to Figure 11. M isolation branches consist of two first isolation branches and x second isolation branches. In this case, the value of x is M-2. The two first isolation branches are denoted as first isolation branch Mr-1 and first isolation branch Mr-2, respectively. The x second isolation branches are denoted as second isolation branches Ms-1, ..., and second isolation branches Ms-x, respectively.

[0096] The first isolation branch Mr-1 is coupled to the output terminals P1 and P2 of the splitter circuit 201 and to the input terminal K1 of the combiner circuit 203. The operating frequency band of the first isolation branch Mr-1 may include the frequency band corresponding to output terminal P1 and the frequency band corresponding to output terminal P2. The first isolation branch Mr-1 transmits the signals given by output terminals P1 and P2 to the input terminal K1 of the combiner circuit 203, and can prevent the reflected signals generated in the combiner circuit 203 from being transmitted to the output terminals P1 and P2 of the splitter circuit 201.

[0097] Similarly, the first isolation branch Mr-2 is coupled to the output terminals P3 and P4 of the splitter circuit 201 and to the input terminal K2 of the combiner circuit 203. The operating frequency band of the first isolation branch Mr-2 may include the frequency band corresponding to the output terminal P3 and the frequency band corresponding to the output terminal P4. The first isolation branch Mr-2 transmits the signals given by the output terminals P3 and P4 to the input terminal K2 of the combiner circuit 203, and can prevent reflected signals generated in the combiner circuit 203 or antenna 103 from being transmitted to the output terminals P3 and P4 of the splitter circuit 201.

[0098] The second isolation branch Ms-1 is coupled to the output terminal P5 of the splitter circuit 201 and to the output terminal K3 of the combiner circuit 203. The operating frequency band of the second isolation branch Ms-1 may include the frequency band corresponding to the output terminal P5. The second isolation branch Ms-1 transmits the signal given by the output terminal P5 to the input terminal K3 of the combiner circuit 203, preventing the reflected signal generated in the combiner circuit 203 from being transmitted to the output terminal P5 of the splitter circuit 201.

[0099] Similarly, the second isolation branch Ms-x is coupled to the output terminal PN of the splitter circuit 201 and to the output terminal KM of the combiner circuit 203. The operating frequency band of the second isolation branch Ms-x may include the frequency band corresponding to the output terminal PN. The second isolation branch Ms-x can transmit the signal given by the output terminal PN to the input terminal KM of the combiner circuit 203, preventing the reflected signal generated in the combiner circuit 203 from being transmitted to the output terminal PN of the splitter circuit 201.

[0100] From the above description, it can be learned that the signal output by the output terminal Pi of the splitter circuit 201 can be transmitted to the combining circuit 203 by using an isolation branch coupled to the output terminal Pi. Furthermore, the isolation branch coupled to the output terminal Pi can isolate the reflected signal generated in the combining circuit 203, preventing the reflected signal from affecting the power amplification module. Each isolation branch may include an isolator or circulator. Such a design can reduce the requirements of each isolation branch for the operating frequency bandwidth range, and isolators or circulators with a smaller operating frequency bandwidth range can be used to reduce the insertion loss and intermodulation distortion range of the radio frequency isolation module. Furthermore, the radio frequency isolation module can support higher power.

[0101] In another example, Figure 12 shows a diagram of a specific structure of a radio frequency isolation module. The radio frequency isolation module 102 may be coupled to a power amplification module 101. Optionally, the power amplification module 101 may have the structure shown in Figure 4. Alternatively, the power amplification module 101 may use a different structure. This is not particularly limited in this embodiment of the present application. For details of the splitter circuit 201 in the radio frequency isolation module, please refer to the relevant description of the splitter circuit 201 shown in Figure 4. Details are not described again here.

[0102] The radio frequency isolation module 102 may support three frequency bands, which are designated as the first frequency band, the second frequency band, and the third frequency band, respectively. The splitter circuit 201 may include three output terminals. Output terminal P1 corresponds to the first frequency band, output terminal P2 corresponds to the second frequency band, and output terminal P3 corresponds to the third frequency band. The isolation circuit 202 includes two isolation branches, which are the first isolation branch Mr-1 and the second isolation branch Ms-1, respectively.

[0103] The first isolation branch Mr-1 is coupled to output terminals P1 and P2, and the second isolation branch Ms-1 is coupled to output terminal P3. The combining circuit 203 has two input terminals, input terminal K1 is coupled to the first isolation branch Mr-1, and input terminal K2 is coupled to the second isolation branch Ms-1.

[0104] The splitter circuit 201 can perform inter-frequency division processing on the received signal. If the signal received by the splitter circuit 201 includes a signal in a first frequency band, the splitter circuit 201 can output a signal in the first frequency band by using output terminal P1. If the signal received by the splitter circuit 201 includes a signal in a second frequency band, the splitter circuit 201 can output a signal in the second frequency band by using output terminal P2. If the signal received by the splitter circuit 201 includes a signal in a third frequency band, the splitter circuit 201 can output a signal in the third frequency band by using output terminal P3. If the signal received by the splitter circuit 201 includes both a signal in the first frequency band and a signal in the second frequency band, after performing inter-frequency division processing on the received signal, the splitter circuit 201 outputs a signal in the first frequency band by using output terminal P1 and outputs a signal in the second frequency band by using output terminal P2. If the signal received by the splitter circuit 201 includes a signal in a first frequency band and a signal in a third frequency band, after performing inter-frequency splitting on the received signal, the splitter circuit 201 may output the signal in the first frequency band using output terminal P1 and the signal in the third frequency band using output terminal P3. If the signal received by the splitter circuit 201 includes a signal in a second frequency band and a signal in a third frequency band, after performing inter-frequency splitting on the received signal, the splitter circuit 201 may output the signal in the second frequency band using output terminal P2 and the signal in the third frequency band using output terminal P3. If the signal received by the splitter circuit 201 includes a signal in a first frequency band, a signal in a second frequency band, and a signal in a third frequency band, the splitter circuit 201 performs inter-frequency splitting on the received signal, and then outputs the signal in the first frequency band using output terminal P1, the signal in the second frequency band using output terminal P2, and the signal in the third frequency band using output terminal P3.

[0105] The first isolation branch Mr-1 can transmit a signal of the first frequency band provided by output terminal P1 to input terminal K1 of the combining circuit 203, and a signal of the second frequency band provided by output terminal P2 to input terminal K1 of the combining circuit 203, thereby preventing reflected signals generated in the combining circuit 203 from being transmitted to output terminals P1 and P2. The second isolation branch Ms-1 can transmit a signal of the third frequency band provided by output terminal P3 to input terminal K3 of the combining circuit 203, thereby preventing reflected signals generated in the combining circuit 203 from being transmitted to output terminal P3. The combining circuit 203 can perform interfrequency coupling on the signals of the first and second frequency bands provided by the first isolation branch Mr-1 and the signal of the third frequency band provided by the second isolation branch Ms-1, and after combining the signals into a signal on one path, it can output the combined signal to antenna 103.

[0106] In the above embodiment, the first frequency band may be a frequency band from 758 MHz to 960 MHz, the second frequency band may be a frequency band of 1.8 GHz, and the third frequency band may be a frequency band of 2.1 GHz. Alternatively, the first frequency band may be a frequency band from 758 MHz to 960 MHz, the second frequency band may be a frequency band of 2.1 GHz, and the third frequency band may be a frequency band of 2.6 GHz. Alternatively, the first frequency band may be a frequency band from 758 MHz to 960 MHz, the second frequency band may be a frequency band of 2.6 GHz, and the third frequency band may be a frequency band of 1.8 GHz. Alternatively, the first frequency band may be a frequency band of 1.8 GHz, the second frequency band may be a frequency band of 2.1 GHz, and the third frequency band may be a frequency band of 2.6 GHz.

[0107] It will be apparent to those skilled in the art that various modifications and changes can be made to this application without departing from the scope of protection. In this case, if the modifications and changes to this application fall within the scope of the claims of this application and their equivalent art, then this application also includes the modifications and changes.

Claims

1. A radio frequency isolation module, wherein the operating frequency band of the radio frequency isolation module comprises N frequency bands, where N is an integer greater than 1, and the radio frequency isolation module comprises a splitting circuit, an isolation circuit having at least one isolation branch, and a combining circuit. The splitter circuit comprises an input terminal and N output terminals, the input terminal being coupled to a power amplification module and configured to receive a target radio frequency signal from the power amplification module, the target radio frequency signal comprising signals in S frequency bands, where S is an integer less than or equal to N, the N output terminals corresponding one-to-one with the N frequency bands, one output terminal being coupled to one isolation branch, and each output terminal being configured to output a signal in the frequency band corresponding to the coupled isolation branch, the splitter circuit being configured to split the target radio frequency signal into signals in each of the S frequency bands and to output the signals using the output terminals corresponding to each frequency band. Each isolation branch is coupled to the combining circuit and configured to transmit a signal provided by one output terminal of a splitter circuit coupled to the combining circuit. The combining circuit is coupled to the antenna and configured to combine the signals transmitted by the isolation branch in the isolation circuit and output the combined signal to the antenna. The isolation circuit comprises M isolation branches, where M is an integer less than N, and one of the M isolation branches is connected to at least one of the output terminals. A radio frequency isolation module wherein the operating frequency band of the isolation branch covers the frequency band corresponding to each of the at least one output terminals coupled to the isolation branch.

2. The module according to claim 1, wherein the operating frequency band of the radio frequency isolation module covers the operating frequency band of the power amplification module.

3. The module according to claim 1 or 2, wherein the division circuit comprises at least one splitter.

4. The module according to claim 1 or 2, wherein the isolation branch comprises an isolator.

5. The module according to claim 1, wherein the combining circuit comprises a multiband combiner.

6. The module according to claim 5, wherein the combining circuit comprises at least one filter, the at least one isolation branch corresponds one-to-one with the at least one filter, each isolation branch is coupled to the multiband combiner by using the corresponding filter, and the operating frequency bandwidth of each filter is the same as the operating frequency bandwidth of the coupled isolation branch.

7. A communication system comprising a transmitter, a power amplification module, and a radio frequency isolation module, The transmitter is configured to generate a first radio frequency signal. The power amplification module is configured to be separately coupled to the transmitter and the radio frequency isolation module, amplify the first radio frequency signal to obtain a second radio frequency signal, and output the second radio frequency signal to the radio frequency isolation module. The operating frequency band of the radio frequency isolation module comprises N frequency bands, where N is an integer greater than 1, and the radio frequency isolation module comprises a splitting circuit, an isolation circuit having at least one isolation branch, and a combining circuit. The splitter circuit comprises an input terminal and N output terminals, the input terminal configured to receive the second radio frequency signal from the power amplification module, the second radio frequency signal comprising signals of S frequency bands, where S is an integer less than or equal to N, the N output terminals corresponding one-to-one with the N frequency bands, one output terminal coupled to one isolation branch, and each output terminal configured to output a signal of the frequency band corresponding to the coupled isolation branch, the splitter circuit is configured to split the second radio frequency signal into signals of each frequency band provided in the S frequency bands, and to output the signal by using the output terminal corresponding to each frequency band. Each isolation branch is coupled to the combining circuit and configured to transmit a signal provided by one output terminal of a splitter circuit coupled to the combining circuit. The combining circuit is coupled to the antenna and configured to combine the signals transmitted by the isolation branch in the isolation circuit and output the combined signal to the antenna. The isolation circuit comprises M isolation branches, where M is an integer less than N, and one of the M isolation branches is connected to at least one of the output terminals. A communication system in which the operating frequency band of the isolation branch covers the frequency band corresponding to each of the at least one output terminals coupled to the isolation branch.

8. The power amplification module comprises a power splitter, a plurality of power amplification circuits, and a first combiner. The power splitter is coupled to each power amplifier circuit and is configured to allocate power to the first radio frequency signal and output a third radio frequency signal to each power amplifier circuit, wherein the sum of the powers of all the third radio frequency signals output by the power splitter is the same as the power of the first radio frequency signal. Each power amplifier circuit is coupled to the first combiner and configured to perform power amplification on the received third radio frequency signal and output the third radio frequency signal to the first combiner. The system according to claim 7, wherein the first combiner is coupled to the radio frequency isolation module and is configured to synthesize signals separately output by the plurality of power amplification circuits to obtain the second radio frequency signal and output the second radio frequency signal to the radio frequency isolation module.

9. The system according to claim 7 or 8, wherein the operating frequency band of the radio frequency isolation module covers the operating frequency band of the power amplification module.

10. The system according to claim 7 or 8, wherein the dividing circuit comprises at least one splitter, and the isolation branch comprises an isolator or a circulator.

11. The system according to claim 7 or 8, wherein the combining circuit comprises a multiband combiner, the combining circuit comprises at least one filter, the at least one isolation branch corresponds one-to-one with the at least one filter, each isolation branch is coupled to the multiband combiner by using the corresponding filter, and the operating frequency bandwidth of each filter is the same as the operating frequency bandwidth of the coupled isolation branch.

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