RF front-end module

Abstract

This application provides a radio frequency (RF) front-end module, relating to the field of RF technology. The RF front-end module includes a power amplification module, a signal coupling module, and a detection module. The signal coupling module includes a control unit and a bidirectional coupling circuit, which is connected between the power amplification module and the detection module. The control unit is configured to control the bidirectional coupling circuit to be in a conducting state. The bidirectional coupling circuit is configured to couple the RF signal on the signal transmission line of the power amplification module to the detection module. The detection module is configured to detect a pre-distortion signal based on the coupled signal transmitted by the bidirectional coupling circuit. This application achieves bidirectional coupling by coupling the transmitted and echo signals on the signal transmission line of the power amplification module to the detection module, thereby enabling accurate detection and feedback of the nonlinear characteristics of the power amplification module's core. Based on this, the pre-distortion signal determined is more accurate.

Description

Technical Field

[0001] This application relates to the field of radio frequency technology, and in particular to a radio frequency front-end module. Background Technology

[0002] When a power amplifier operates in its high-efficiency region (such as near saturation), its input-output relationship exhibits nonlinear characteristics, resulting in amplitude-amplitude distortion and amplitude-phase distortion. Traditional methods reduce distortion by "power back-off" to keep the power amplifier operating in the linear region, but this significantly reduces efficiency.

[0003] Traditional solutions propose a Digital Pre-Distortion (DPD) approach, which uses a coupler to couple the RF signal, estimates the pre-distortion signal based on the coupled signal, and performs distortion compensation based on the pre-distortion signal. However, the coupler is typically a power coupler adapted from the antenna port. However, power couplers adapted to antenna ports are directional couplers, which can only couple RF signals in one direction, making it impossible to detect the pre-distortion signal, which reflects the overall impedance. Summary of the Invention

[0004] This application provides an RF front-end module that can accurately detect and feedback the actual nonlinear signal of the power amplifier core, thereby providing a reliable basis for distortion compensation. It has a simple structure and small size, which can meet the needs of RF front-end modules with high integration requirements.

[0005] The technical solution of this application embodiment is implemented as follows: In a first aspect, embodiments of this application provide a radio frequency front-end module, including: a power amplification module, a signal coupling module, and a detection module, wherein the signal coupling module includes a control unit and a bidirectional coupling circuit, and the bidirectional coupling circuit is connected between the power amplification module and the detection module; The control unit is configured to control the bidirectional coupling circuit to be in the on state; The bidirectional coupling circuit is configured to couple the radio frequency signal on the signal transmission line of the power amplifier module to the detector module; The detection module is configured to detect the predistortion signal based on the coupled signal transmitted by the bidirectional coupling circuit.

[0006] Through the above technical solution, this application uses a bidirectional coupling circuit to couple the transmitted signal and echo signal on the signal transmission line of the power amplifier module to the detection module, thereby achieving bidirectional coupling. This enables accurate detection and feedback of the nonlinear characteristics of the core of the power amplifier module, and the predistortion signal determined on this basis is more accurate, which is beneficial for distortion compensation.

[0007] In one embodiment, the bidirectional coupling circuit includes a capacitor unit, which includes one or more first capacitors, and the capacitor unit is connected between the power amplifier module and the detector module. The capacitor unit is configured to couple the radio frequency signal on the signal transmission line of the power amplifier module to the detector module.

[0008] Through the above technical solution, the embodiments of this application include a bidirectional coupling circuit with a capacitor unit, which can be a single capacitor. Therefore, the structure is simple and the size is small, which can meet the high integration requirements of high-end RF front-end modules.

[0009] In one embodiment, the bidirectional coupling circuit further includes a switch array, which includes a plurality of first switches, each of which is connected to a plurality of first capacitors in a one-to-one correspondence, and the control unit is connected to the switch array. The control unit is also configured to control the first target switch among a plurality of first switches to be in a closed state, and to control the first switches other than the first target switch to be in an open state; The first capacitor connected to the first target switch is used to couple the radio frequency signal on the signal transmission line of the power amplifier module to the detector module.

[0010] Through the above technical solution, the embodiments of this application set up a switch array and a capacitor array, and then flexibly increase or decrease the number of the first conducting capacitors according to the needs, thereby adjusting the size of the equivalent capacitor to meet the needs of different signal frequency bands.

[0011] In one embodiment, the radio frequency front-end module is used to transmit radio frequency signals in multiple signal frequency bands, wherein: The control unit is also configured to determine a first target switch from a plurality of first switches according to the target signal frequency band corresponding to the power amplification module, and control the first target switch to be in a closed state; the first capacitor connected to the first target switch forms an equivalent capacitance that matches the target signal frequency band, and the target signal frequency band is one of a plurality of signal frequency bands.

[0012] Through the above technical solution, the embodiments of this application determine the first target switch by matching the corresponding equivalent capacitor according to the target signal frequency band of the power amplification module, and control the first target switch to be in a closed state, so that the first capacitor connected to the first target switch can form an equivalent capacitor that matches the target signal frequency band, so that the signal coupling module can meet the frequency band requirements of the power amplification module.

[0013] In one embodiment, the bidirectional coupling circuit further includes a pull-down switch connected between the output terminal of the capacitor unit and the ground terminal, and the control unit is connected to the pull-down switch; The control unit is also configured to control the pull-down switch to be in the closed state; When the pull-down switch is in the closed state, the capacitor unit is grounded.

[0014] Through the above technical solution, the embodiments of this application can flexibly switch its structure to the pull-down isolation state by means of a pull-down switch, ensuring sufficient isolation between PAs during the period of non-use, thereby improving system security.

[0015] In one embodiment, the bidirectional coupling circuit further includes a switching module, which is disposed at the output terminal of the capacitor unit, and the control unit is connected to the switching module; wherein, the switching module includes two contacts, the first contact is connected to the detector module, and the second contact is connected to the ground terminal; The control unit is also configured to either connect the control switch module to the first contact or connect the control switch module to the second contact. When the switch module is connected to the first contact, the capacitor unit is used to couple the radio frequency signal output by the power amplifier module to the detector module; when the switch module is connected to the second contact, the capacitor unit is grounded.

[0016] Through the above technical solution, the embodiments of this application can achieve that only one contact is conducting at the same time by using a dual-contact switch, thereby ensuring that the bidirectional coupling circuit is either in a conducting state or in a grounded state, avoiding coupling during the period when the power amplifier module is not working, which would cause interference to the detection module.

[0017] In one embodiment, the radio frequency front-end module includes multiple power amplification modules, each power amplification module is provided with a signal coupling module, and the multiple power amplification modules operate in different frequency bands. The outputs of multiple signal coupling modules are connected to the detection module.

[0018] Through the above technical solution, the embodiments of this application set each signal coupling module to be connected to the detection module separately, so that the coupling signals transmitted by each signal coupling module do not interfere with each other, which can improve the isolation between power amplification modules.

[0019] In one embodiment, the radio frequency front-end module includes multiple power amplification modules, each power amplification module is provided with a signal coupling module, and the multiple power amplification modules operate in different frequency bands. The outputs of multiple signal coupling modules are connected to the input of the signal bus, and the output of the signal bus is connected to the detection module.

[0020] Through the above technical solution, in the embodiments of this application, since only one power amplifier module works in the RF front-end module at the same time, correspondingly, only one signal coupling module couples the RF signal. Based on this, the multiple signal coupling modules can share the signal bus in a time-division multiplexing manner, which can not only ensure the isolation between power amplifier modules, but also reduce wiring and optimize the line structure.

[0021] In one embodiment, the RF front-end module further includes a filtering module and an antenna module, with the filtering module connected between the power amplifier module and the antenna module.

[0022] Through the above technical solution, the embodiments of this application can filter interference signals and enhance the strength of radio frequency signals by setting a filtering module.

[0023] In one embodiment, the RF front-end module further includes a frequency selection module connected between the power amplifier module and the filter module.

[0024] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and are not intended to limit the technical solutions of this application. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 1 ; Figure 2 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 2 ; Figure 3 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 3 ; Figure 4 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 4 ; Figure 5 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 5 ; Figure 6 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 6 ; Figure 7 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 7 ; Figure 8 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 8 ; Figure 9This is a schematic diagram of the circuit structure of a radio frequency front-end module provided in an embodiment of this application. Figure 1 ; Figure 10 This is a schematic diagram of the circuit structure of a radio frequency front-end module provided in an embodiment of this application. Figure 2 . Detailed Implementation

[0026] In order to gain a more detailed understanding of the features and technical content of the embodiments of this application, the implementation of the embodiments of this application will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for reference and illustration only and are not intended to limit the embodiments of this application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0028] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0029] It should also be noted that the terms "first, second, and third" used in the embodiments of this application are only used to distinguish similar objects and do not represent a specific order of objects. It is understood that "first, second, and third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0030] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] Existing radio frequency (RF) front-end modules are widely used in wireless communication, the Internet of Things (IoT), smart homes, and other fields. Among them, the power amplifier, as the core unit of the RF front-end module, has a significant impact on the signal output performance of the RF front-end module.

[0032] When a power amplifier operates in its high-efficiency region (such as near-saturation region), its input-output relationship exhibits nonlinear characteristics, resulting in amplitude-amplitude distortion and amplitude-phase distortion.

[0033] Traditional methods use "power back-off" to keep the power amplifier operating in the linear region to reduce distortion, but this significantly reduces efficiency.

[0034] To ensure efficiency, a Digital Pre-Distortion (DPD) scheme has been proposed. In the DPD scheme, a small portion of the signal from the output link of the power amplifier (PA) is extracted using a power coupler for error calculation. This includes comparing the original signal u(n) with the feedback signal y'(n) to obtain the error signal e(n). This error signal is a vector signal and can be expressed as e(n) = u(n) - y'(n) / G, where G is the ideal gain of the PA. This error signal, combined with the original baseband signal, can be used to calculate the pre-distortion signal, and then distortion compensation can be performed based on the pre-distortion signal.

[0035] The existing DPD solution has the following two problems: (1) Copying the antenna-end power coupler directly results in a large area that requires a significant amount of space in the RF front-end module.

[0036] For high-end RF front-end modules commonly used in mid-to-high-end smartphones, such as L-PAMiD (a fully integrated RF front-end module / chip that integrates a receiver low-noise amplifier, a transmitter power amplifier, a duplexer, and corresponding switches) or L-PAMiF (a fully integrated RF front-end module / chip that integrates a receiver low-noise amplifier, a transmitter power amplifier, a filter, and corresponding switches), the integration is higher and the module area is smaller and smaller. Couplers used for DPDs do not have much area budget, so the large antenna-end power couplers cannot be used in high-end RF front-end modules.

[0037] (2) Antenna-end power couplers are usually directional couplers, which can only couple signals in one direction.

[0038] Directional couplers typically only couple the transmitted signal and cannot couple the echo signal. However, power amplifiers are actually affected by both the transmitted and echo signals, so the signal coupled by the antenna-end power coupler cannot detect the nonlinear characteristics of the power amplifier core.

[0039] Given the aforementioned issues, a solution that can accurately detect and feedback the actual nonlinearity of the power amplifier core, while being small enough not to impose area constraints on the RF front-end module, is particularly important.

[0040] This application provides a radio frequency (RF) front-end module, which includes a power amplification module, a signal coupling module, and a detection module. The signal coupling module includes a control unit and a bidirectional coupling circuit connected between the power amplification module and the detection module. The control unit is configured to keep the bidirectional coupling circuit in a conducting state. The bidirectional coupling circuit is configured to couple the RF signal on the signal transmission line of the power amplification module to the detection module. The detection module is configured to detect a pre-distortion signal based on the coupled signal transmitted by the bidirectional coupling circuit. This application achieves bidirectional coupling by coupling the transmitted and echo signals on the signal transmission line of the power amplification module to the detection module, thereby enabling accurate detection and feedback of the nonlinear characteristics of the power amplification module's core. The pre-distortion signal determined based on this is more accurate, which is beneficial for distortion compensation.

[0041] In addition, in the embodiments of this application, the bidirectional coupling circuit includes a capacitor unit, which can be a single capacitor. Therefore, the structure is simple and the size is small, which can meet the high integration requirements of high-end RF front-end modules.

[0042] The various embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0043] This application provides a radio frequency (RF) front-end module, which integrates two or more discrete components such as RF switches, low-noise amplifiers, filters, duplexers, and power amplifiers into a single module, thereby improving integration and hardware performance while miniaturizing the device. Specifically, the RF front-end module can be applied to communication devices such as smartphones, tablets, and smartwatches.

[0044] Please refer to Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 1 , Figure 2 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 2 The RF front-end module includes a power amplifier module 101, a signal coupling module 102, and a detector module 103.

[0045] In this embodiment, the power amplifier module 101 is used to amplify the power of the radio frequency signal. The power amplifier module 101 includes an radio frequency input port and a power amplifier. The power amplifier module can be a single-ended power amplifier or a differential power amplifier. Specifically, the power amplifier module can include one or more transistors, such as bipolar junction transistors (BJTs), metal-oxide-semiconductor field-effect transistors (MOSFETs), heterojunction bipolar transistors (HBTs), etc.

[0046] In the embodiments of this application, such as Figure 1 As shown, the transmitter can input the radio frequency (RF) signal into the power amplifier through the RF input port. The power amplifier amplifies the input RF signal and transmits the amplified RF signal to the subsequent system. During the transmission of the RF signal from the power amplifier module 101 to the subsequent system via the signal transmission line, the signal coupling module 102 can couple the RF signal transmitted by the power amplifier module 101 to the detector module 103.

[0047] like Figure 1 As shown, the signal coupling module 102 includes a control unit 1021 and a bidirectional coupling circuit 1022. The bidirectional coupling circuit 1022 is connected between the power amplification module 101 and the detection module 103, as follows: Figure 1 As shown, a lead is drawn from the signal transmission line between the power amplifier module 101 and the subsequent system and connected to the bidirectional coupling circuit 1022. The control unit 1021 is connected to the bidirectional coupling circuit 1022.

[0048] The control unit 1021 is configured to control the bidirectional coupling circuit 1022 to be in a conducting state when the power amplification module 101 is working; the bidirectional coupling circuit 1022 is configured to couple the radio frequency signal transmitted by the power amplification module 101 to the detection module 103; the detection module 103 is configured to detect the pre-distortion signal based on the coupling signal transmitted by the bidirectional coupling circuit 1022.

[0049] In some embodiments, when the power amplifier module 101 is in operation, the control unit 1021 can control the bidirectional coupling circuit 1022 to be turned on, so that the bidirectional coupling circuit 1022 can couple the radio frequency signal on the signal transmission line of the power amplifier module 101 to the detector module 103.

[0050] When the power amplifier module 101 is not in operation, the control unit 1021 can control the connection between the bidirectional coupling circuit 1022 and the power amplifier module 101 to be disconnected. This ensures that the power amplifier module is isolated during the period when the power amplifier module 101 is not in use, thereby improving system safety.

[0051] In some embodiments, a control switch may be provided on the bidirectional coupling circuit 1022, and the control unit 1021 may control the bidirectional coupling circuit 1022 to be turned on or off through the control switch. The control switch may be located at one end of the bidirectional coupling circuit 1022 near the power amplifier module 101, or it may be located at one end of the bidirectional coupling circuit 1022 near the detector module 103.

[0052] In this embodiment, the bidirectional coupling circuit 1022 is capable of bidirectional coupling of the transmitted signal (hereinafter referred to as the radio frequency signal) output from the power amplifier module 101 to the antenna module 105 and the echo signal (hereinafter referred to as the radio frequency signal) returned from the antenna module 105 to the power amplifier module 101, so that the coupled signal transmitted to the detector module 103 includes the forward transmitted signal and the reverse echo signal.

[0053] The radio frequency front-end module provided in this application embodiment couples the transmitted signal and echo signal on the signal transmission line of the power amplifier module to the detection module through a bidirectional coupling circuit, thereby achieving bidirectional coupling. This enables accurate detection and feedback of the nonlinear characteristics of the core of the power amplifier module, allowing the detection module to estimate an accurate pre-distortion signal for distortion compensation.

[0054] Based on the above embodiments, such as Figure 2 As shown, the subsequent system includes a filtering module 104 and an antenna module 105. In this embodiment, the filtering module 104 is connected between the power amplifier module 101 and the antenna module 105. The power amplifier module 101 transmits the enhanced radio frequency signal to the filtering module 104 via a signal transmission line. After filtering, the signal is transmitted to the antenna module 105, which then transmits the radio frequency signal.

[0055] In some embodiments, such as Figure 2 As shown, the subsequent system also includes a frequency selection module 106, which is connected between the power amplifier module 101 and the filter module 104. The frequency selection module 106 is used to output the radio frequency signal of the target frequency band to the filtering module 104, and then send it to the antenna module 105 after filtering. The target frequency band is the operating frequency band of the power amplifier module. For example, if the power amplifier module 101 can transmit radio frequency signals of three frequency bands, namely B71, B20, and B12, and the target frequency band is B20, then when the power amplifier module 101 transmits radio frequency signals of the B20 frequency band, the radio frequency signal of the B20 frequency band can be output to the filtering module 104 and the antenna module 105 through the frequency selection module 106; when the power amplifier module 101 transmits radio frequency signals of the B71 or B12 frequency band, the radio frequency signal of the B71 or B12 frequency band will be blocked by the frequency selection module 106 and thus cannot be output to the filtering module 104 and the antenna module 105.

[0056] Based on the above embodiments, please refer to Figure 3 , Figure 3 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 3 The bidirectional coupling circuit 1022 includes a capacitor unit C, which is connected between the power amplifier module 101 and the detector module 103. When the bidirectional coupling circuit 1022 is turned on, the capacitor unit C can couple the radio frequency signal transmitted by the power amplifier module 101 to the detector module 103.

[0057] In this embodiment, the capacitance value of capacitor unit C is matched with the operating frequency band of power amplifier module 101 to ensure that signal coupling module 102 is within a reasonable range.

[0058] In some embodiments, capacitor unit C includes one or more first capacitors, wherein when capacitor unit C includes only one first capacitor c, the capacitance value of the first capacitor c matches the operating frequency band of power amplifier module 101. For example... Figure 3 As shown, Figure 3 The diagram illustrates a bidirectional coupling circuit 1022 comprising only a first capacitor. One end of this first capacitor c is connected to the lead between the power amplifier module 101 and the frequency selection module 106, and the other end is connected to the detector module 103.

[0059] In other embodiments, the capacitor unit C includes a plurality of first capacitors. These first capacitors may be connected in series or in parallel, and their capacitance values ​​may be equal or unequal. These first capacitors constitute a capacitor array, meaning the capacitor unit includes a capacitor array. Please refer to [reference needed]. Figure 4 , Figure 4 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 4The RF front-end module includes a power amplifier module 101, a signal coupling module 102, a detector module 103, a frequency selection module 106, a filter module 104, and an antenna module 105. The signal coupling module 102 includes a control unit 1021 and a bidirectional coupling circuit 1022. The bidirectional coupling circuit 1022 includes a capacitor unit, which comprises multiple first capacitors. The number of first capacitors can be flexibly increased or decreased according to the operating frequency band of the power amplifier module.

[0060] like Figure 3 and Figure 4 As shown in the embodiment of this application, the bidirectional coupling circuit 1022 further includes a control switch K, which is disposed at the output end of the capacitor unit. The control unit 1021 is connected to the control switch K and controls the bidirectional coupling circuit 1022 to be turned on or off through the control switch K.

[0061] In other embodiments, the control switch K is a two-contact switch, wherein the two-contact switch includes a first contact and a second contact, the first contact is connected to the detector module, the second contact is connected to the ground terminal, the two-contact switch is connected to the control unit 1021, and the control unit 1021 controls the bidirectional coupling circuit 1022 by controlling the two-contact switch.

[0062] Specifically, when the control unit 1021 controls the first contact of the two-contact switch to close, the first capacitor c can couple the radio frequency signal on the signal transmission line of the power amplifier module 101 to the detector module 103. When the control unit 1021 controls the second contact of the two-contact switch to close, the first capacitor c is grounded, and coupling stops.

[0063] In the RF front-end module provided in this application embodiment, the signal coupling module consists of a control unit and a capacitor c. The capacitor c is non-directional, so it can bidirectionally sense the transmitted signal and the echo signal, thereby accurately detecting and feeding back the nonlinear characteristics of the power amplifier module core, so that the detection module can estimate the accurate pre-distortion signal for distortion compensation.

[0064] Please refer to Figure 5 , Figure 5 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 5 The RF front-end module includes a power amplifier module 101, a signal coupling module 102, a detector module 103, a frequency selection module 106, a filter module 104, and an antenna module 105.

[0065] The signal coupling module 102 includes a control unit 1021 and a bidirectional coupling circuit 1022. The bidirectional coupling circuit 1022 includes a capacitor unit, which includes a capacitor array, and the capacitor array includes multiple first capacitors. The bidirectional coupling circuit 1022 also includes a switch array. The control unit 1021 is connected to the switch array. The switch array includes multiple first switches, and the multiple first switches and multiple first capacitors are connected in a one-to-one correspondence.

[0066] In the embodiments of this application, a first switch is connected to a first capacitor, and each first capacitor is connected to a different first switch.

[0067] In this embodiment of the application, the control unit is further configured to control the first target switch among a plurality of first switches to be in a closed state, and to control the first switches other than the first target switch to be in an open state; wherein, the first capacitor connected to the first target switch is used to couple the radio frequency signal on the signal transmission line of the power amplifier module to the detector module.

[0068] Here, the first target switch refers to the first selected switch in the switch array that is in the closed state. When the first target switch is in the closed state, the first capacitor connected to the first target switch can form an equivalent capacitance, and this equivalent capacitance matches the operating frequency band of the power amplifier module.

[0069] In the embodiments of this application, different numbers of first capacitors can be combined to form different equivalent capacitors, and different equivalent capacitors can cover different signal frequency bands.

[0070] In this embodiment, when the signal coupling module 102 couples the radio frequency signal transmitted by the power amplifier module, it needs to match the frequency band to which the radio frequency signal belongs. To achieve this matching, in this embodiment, the control unit 1021 is configured to determine a first target switch from a plurality of first switches according to the target signal frequency band corresponding to the power amplifier module, and control the first target switch to be in a closed state; the first capacitor connected to the first target switch forms an equivalent capacitance that matches the target signal frequency band.

[0071] The target signal frequency band is one of the multiple signal frequency bands covered by the RF front-end module, and it is also the operating frequency band of the power amplifier module.

[0072] This application embodiment adjusts the equivalent capacitance by setting up a switch array and a capacitor array, and then flexibly increasing or decreasing the number of conducting first capacitors as needed to meet the requirements of different signal frequency bands. Furthermore, the signal coupling module provided in this application embodiment includes a control unit, a switch array, and a capacitor array. It has a simple structure, a sufficiently small area, and does not introduce significant insertion loss into the main transmission path, allowing for flexible integration into the RF front-end module.

[0073] Based on the above embodiments, this application also provides a radio frequency front-end module, such as... Figure 6 As shown, Figure 6 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 6 The RF front-end module includes multiple power amplifier modules, each of which is paired with a signal coupling module. The multiple power amplifier modules operate in different frequency bands.

[0074] The RF front-end module can transmit RF signals across multiple frequency bands, which are distinct from each other. For example, these bands could be B71, B20, B12, B13, B26, and B8. In different scenarios, different frequency bands of RF signals will be input to the power amplifier module. Different frequency bands require different equivalent capacitances to ensure the signal coupling module operates within a reasonable range.

[0075] Figure 6 The diagram illustrates two power amplification modules, A1 and B1. The radio frequency (RF) signal output from power amplification module A1 is transmitted to a downstream system, which includes a frequency selection module A3, a filtering module A4, and an antenna module A5 connected in sequence. Power amplification module A1 also has a corresponding signal coupling module A2, which couples the RF signal transmitted by power amplification module A1 to a detection module C.

[0076] The radio frequency signal output by the power amplifier module B1 is transmitted to the subsequent system, which includes a frequency selection module B3, a filtering module B4, and an antenna module B5 connected in sequence. The power amplifier module B1 also has a corresponding signal coupling module B2, which couples the radio frequency signal transmitted by the power amplifier module B1 to the detection module C.

[0077] In this embodiment, the outputs of multiple signal coupling modules are respectively connected to the same detection module C.

[0078] Signal coupling module A2 and signal coupling module B2 have identical structures. Taking signal coupling module A2 as an example, it includes a control unit (not shown in the figure) and a bidirectional coupling circuit. The bidirectional coupling circuit includes a switch array, a capacitor array, and a control switch connected in sequence. The switch array includes multiple first switches, and the capacitor array includes multiple first capacitors. The control unit can conduct multiple first capacitors through the first target switch in the switch array. The equivalent capacitance formed by these conducted first capacitors matches the operating frequency band of power amplifier module A1. Similarly, the equivalent capacitance formed by signal coupling module B2 matches the operating frequency band of power amplifier module B1.

[0079] The control switch is connected to the control unit and is used to control the connection or disconnection of the bidirectional coupling circuit and the detection module.

[0080] In this embodiment, power amplification module A1 and power amplification module B1 can correspond to different signal frequency bands, and the equivalent capacitances formed by signal coupling module A2 and signal coupling module B2 are different from each other.

[0081] In this embodiment, the RF front-end module can activate one of multiple power amplifier modules, while controlling the remaining power amplifier modules to be in a non-operating state. Only one frequency band of RF signal will be input to the power amplifier module. That is, at any given time, only one of power amplifier module A1 (along with signal coupling module A2) and power amplifier module B1 (along with signal coupling module B2) is in an operating state, while the other is in a non-operating state.

[0082] In this embodiment, the detection module C further includes a selector, which has multiple input terminals and one output terminal. The output terminal of each signal coupling module is connected to one input terminal of the selector. The selector is used to select one of the multiple coupled signals as the output based on a control signal and provide it to the detection module C. By setting the selector, this embodiment can isolate the coupled signals transmitted by multiple signal coupling modules, avoid interference, and improve system stability.

[0083] Based on the above embodiments, this application further proposes that the output terminals of multiple signal coupling modules are connected to the input terminals of a signal bus, and the output terminals of the signal bus are connected to a detection module. That is, the coupled signals of multiple signal coupling modules share a single signal bus for transmission. In this application embodiment, since only one power amplifier module operates at any given time, correspondingly, only one signal coupling module couples the RF signal. Therefore, the multiple signal coupling modules can share the signal bus using a time-division multiplexing method. This approach can reduce the number of wires in the RF front-end module, lower the wiring difficulty, and improve the integration of the RF front-end module.

[0084] Based on the above embodiments, please refer to Figure 7 , Figure 7 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 7 . Figure 7 The signal coupling module also includes a pull-down switch, which is connected between the output terminal of the capacitor unit and the ground terminal. The control unit (not shown in the figure) is connected to the pull-down switch.

[0085] Among them, the pull-down switch in signal coupling module A2 is as follows Figure 7 As shown in the dashed circle A2-1. The pull-down switch in signal coupling module B2 is as follows. Figure 7 As shown in the dashed circle B2-1, taking signal coupling module A1 as an example, when power amplifier module A1 is in a non-operating state, the control unit can control the pull-down switch A2-1 to be in the closed state, at which time the capacitor unit is grounded. This switches power amplifier module A1 to the pull-down isolation state, ensuring sufficient inter-PA isolation during periods of non-use and avoiding interference to power amplifier module B1. When power amplifier module A1 is in an operating state, the control unit can control the pull-down switch A2-1 to be in the open state, ensuring that the coupled signal can be transmitted normally to the detector module.

[0086] It should be noted that, Figure 7 The grounding terminals of signal coupling module A2 and signal coupling module B2 shown in the figure are separate, but in fact, they can share a grounding terminal.

[0087] In addition, such as Figure 7 As shown in the embodiment of this application, antenna module A5 further includes antenna coupler A5-1, wherein antenna coupler A5-1 is used to couple the radio frequency signals transmitted by the antenna module, including the transmitted signal and the echo signal, and transmit the coupled signal to the detection module C. Similarly, antenna module B5 also includes antenna coupler B5-1, which is used to couple the radio frequency signals transmitted by the antenna module, including the transmitted signal and the echo signal, and transmit the coupled signal to the detection module C.

[0088] This application embodiment can flexibly switch its structure to a pull-down isolation state via a pull-down switch, ensuring sufficient inter-PA isolation during periods of non-use, thereby improving system security.

[0089] Based on the above embodiments, please refer to Figure 8 , Figure 8 This is a schematic diagram of the structure of a radio frequency front-end module provided in an embodiment of this application. Figure 8 The RF front-end module includes multiple power amplification modules, each of which is paired with a signal coupling module. The multiple power amplification modules operate in different frequency bands.

[0090] The signal coupling module includes a control unit (not shown in the figure) and a bidirectional coupling circuit. The bidirectional coupling circuit includes a switch array, a capacitor array, and a switch module connected in sequence. The switch array includes multiple first switches, and the capacitor array includes multiple first capacitors. The control unit can conduct multiple first capacitors through a first target switch in the switch array. The equivalent capacitance formed by these conducted first capacitors matches the operating frequency band of the power amplifier module A1. Similarly, the equivalent capacitance formed by the signal coupling module B2 matches the operating frequency band of the power amplifier module B1.

[0091] The switching module is located at the output end of the capacitor unit, and the control unit is connected to the switching module. The switching module includes two contacts: the first contact is connected to the detector module, and the second contact is connected to the ground terminal. The control unit is also configured to connect the switch module to the first contact when the power amplifier module is working normally, or to connect the switch module to the second contact during periods when the power amplifier module is not working.

[0092] When the switch module is connected to the first contact, the capacitor unit is used to couple the radio frequency signal output by the power amplifier module to the detector module; when the switch module is connected to the second contact, the capacitor unit is grounded.

[0093] Figure 8 The switch module in signal coupling module A2 is represented by dashed coil A2-2, and the switch module in signal coupling module B2 is represented by dashed coil B2-2. This embodiment of the application uses a dual-contact switch to reduce the number of switches in the signal coupling module, further reducing size, area footprint, and improving integration.

[0094] In this embodiment, at any given time, only one contact of the dual-contact switch can be turned on, thereby ensuring that the bidirectional coupling circuit is either in a conducting state or in a grounded state, avoiding coupling during periods when the PA is not working, which could interfere with the detection module.

[0095] Please refer to the above. Figure 9 , Figure 9 This is a schematic diagram of the circuit structure of a radio frequency front-end module provided in an embodiment of this application. Figure 1 This RF front-end module includes multiple power amplifiers. Figure 9 Power amplifiers PA1 and PA2 are shown only as examples. PA1's input is connected to the RF input port RF_IN, and its output is connected to a band switch. The band switch is configured to allow RF signals in a first target frequency band to be output to a filter module DPX1. The filter module DPX1 includes a transmitter side (Tx) and a receiver side (Rx), and the first target frequency band is the operating frequency band of power amplifier PA1. After filtering the RF signal, the filter module DPX1 sends the RF signal to the antenna module, which includes an antenna switch. The antenna module encapsulates the RF signal and sends it to the antenna array ANT1.

[0096] In this embodiment, the power amplifier PA1 is equipped with a signal coupling module CPL1, which is connected to the power amplifier PA1 and the coupled signal output port CPL_OUT. The signal coupling module CPL1 includes a control unit and a bidirectional coupling circuit. The bidirectional coupling circuit includes a switch array, a capacitor array, and a switching module. The switch array includes multiple first switches, and the capacitor array includes multiple first capacitors, with each first switch and capacitor connected in a one-to-one correspondence. The switching module includes a control switch and a pull-down switch. The control switch is connected between the output terminal of the capacitor array and the detection module. The pull-down switch is connected between the output terminal of the capacitor array and the ground terminal.

[0097] In this embodiment, the antenna module further includes an antenna coupler ant1-CPL, which is used to couple the radio frequency signals transmitted by the antenna module, including the transmitted signal and the echo signal, and to transmit the coupled signal to the coupled signal output port CPL_OUT.

[0098] Based on the same principle, the input of PA2 is connected to the RF input port RF_IN, and the output of PA2 is connected to the band switch. The band switch is configured to allow RF signals from the second target frequency band to be output to the filter module DPX2. The filter module DPX2 includes a transmitting side (Tx) and a receiving side (Rx), and the second target frequency band is the operating frequency band of the power amplifier PA2. After filtering the RF signal, the filter module DPX2 sends the RF signal to the antenna module. The antenna module includes an antenna switch, which encapsulates the RF signal before sending it to the antenna array ANT2.

[0099] In this embodiment, the power amplifier PA2 is equipped with a signal coupling module CPL2, which is connected to the power amplifier PA2 and the coupled signal output port CPL_OUT. The signal coupling module CPL2 includes a control unit and a bidirectional coupling circuit. The bidirectional coupling circuit includes a switch array, a capacitor array, and a switching module. The switch array includes multiple first switches, and the capacitor array includes multiple first capacitors, with each first switch and capacitor connected in a one-to-one correspondence. The switching module includes a control switch and a pull-down switch. The control switch is connected between the output terminal of the capacitor array and the detection module. The pull-down switch is connected between the output terminal of the capacitor array and the ground terminal.

[0100] The antenna module also includes an antenna coupler ant2-CPL, which is used to couple the radio frequency signals transmitted by the antenna module, including the transmitted signal and the echo signal, and transmit the coupled signal to the coupled signal output port CPL_OUT.

[0101] In this embodiment, the pull-down switch in signal coupling module CPL1 and the pull-down switch in signal coupling module CPL2 share a common ground terminal.

[0102] It should be noted that, in this embodiment, the coupling signal output port CPL_OUT further includes a gating device, which includes multiple input terminals and one output terminal. For example... Figure 9 As shown, the output of each signal coupling module is connected to one input of a selector. The selector selects one of the coupled signals from multiple signals based on the control signal and outputs it to the coupled signal output port CPL_OUT. By setting the selector, the coupled signals transmitted by multiple signal coupling modules can be isolated, avoiding interference and improving system stability.

[0103] Please refer to Figure 10 , Figure 10 This is a schematic diagram of the circuit structure of a radio frequency front-end module provided in an embodiment of this application. Figure 2 . Figure 10 In this RF front-end module, multiple power amplifiers (such as...) are included. Figure 10 (PA1 and PA2), each power amplifier is equipped with a corresponding signal coupling module (e.g., PA1 and PA2). Figure 10 In this embodiment of the application, the output terminals of multiple signal coupling modules (CPL1 and CPL2) are respectively connected to the input terminal of the signal bus, and the output terminal of the signal bus is connected to the selector of the coupling signal output port CPL_OUT.

[0104] In other words, the coupled signals of multiple signal coupling modules share a single signal bus for transmission. In this embodiment, since only one power amplifier module operates at any given time, correspondingly, only one signal coupling module couples the RF signal. Therefore, these multiple signal coupling modules can share the signal bus using time-division multiplexing. This approach reduces the number of wires in the RF front-end module, lowers wiring complexity, and improves the integration of the RF front-end module.

[0105] It should be noted that, in this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0106] The sequence numbers of the embodiments in this application are merely for descriptive purposes and do not represent the superiority or inferiority of the embodiments. The features disclosed in the several product embodiments provided in this application can be arbitrarily combined to obtain new product embodiments without conflict. Similarly, the features disclosed in the several method or device embodiments provided in this application can be arbitrarily combined to obtain new method or device embodiments without conflict. The above descriptions are merely specific implementations of this application, but the protection scope of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the protection scope of this application.

Claims

1. A radio frequency front-end module, characterized in that, include: The system includes a power amplifier module, a signal coupling module, and a detection module. The signal coupling module includes a control unit and a bidirectional coupling circuit, which is connected between the power amplifier module and the detection module. The control unit is configured to control the bidirectional coupling circuit to be in an on state; The bidirectional coupling circuit is configured to couple the radio frequency signal on the signal transmission line of the power amplifier module to the detector module. The detection module is configured to detect a predistortion signal based on the coupling signal transmitted by the bidirectional coupling circuit.

2. The radio frequency front-end module according to claim 1, characterized in that, The bidirectional coupling circuit includes a capacitor unit, which includes one or more first capacitors, and the capacitor unit is connected between the power amplifier module and the detector module. The capacitor unit is configured to couple the radio frequency signal on the signal transmission line of the power amplifier module to the detector module.

3. The radio frequency front-end module according to claim 2, characterized in that, The bidirectional coupling circuit further includes a switch array, which includes a plurality of first switches, each of which is connected to a plurality of first capacitors in a one-to-one correspondence, and the control unit is connected to the switch array. The control unit is further configured to control the first target switch among the plurality of first switches to be in a closed state, and to control the first switch other than the first target switch to be in an open state; The first capacitor connected to the first target switch is used to couple the radio frequency signal on the signal transmission line of the power amplifier module to the detector module.

4. The radio frequency front-end module according to claim 3, characterized in that, The radio frequency front-end module is used to transmit radio frequency signals in multiple frequency bands, wherein: The control unit is further configured to determine the first target switch from the plurality of first switches according to the target signal frequency band corresponding to the power amplification module, and control the first target switch to be in a closed state; the first capacitor connected to the first target switch forms an equivalent capacitance matching the target signal frequency band, and the target signal frequency band is one of the plurality of signal frequency bands.

5. The radio frequency front-end module according to any one of claims 2-4, characterized in that, The bidirectional coupling circuit also includes a pull-down switch, which is connected between the output terminal of the capacitor unit and the ground terminal, and the control unit is connected to the pull-down switch. The control unit is also configured to control the pull-down switch to be in a closed state; When the pull-down switch is in the closed state, the capacitor unit is grounded.

6. The radio frequency front-end module according to any one of claims 2-4, characterized in that, The bidirectional coupling circuit further includes a switching module, which is disposed at the output terminal of the capacitor unit, and the control unit is connected to the switching module; wherein, the switching module includes two contacts, the first contact is connected to the detector module, and the second contact is connected to the ground terminal; The control unit is further configured to control the switch module to be connected to the first contact, or to control the switch module to be connected to the second contact; When the switch module is connected to the first contact, the capacitor unit is used to couple the radio frequency signal output by the power amplifier module to the detector module; when the switch module is connected to the second contact, the capacitor unit is grounded.

7. The radio frequency front-end module according to any one of claims 2-4, characterized in that, The radio frequency front-end module includes multiple power amplification modules, and each power amplification module is configured with a signal coupling module. The multiple power amplification modules operate in different frequency bands. The output terminals of the multiple signal coupling modules are respectively connected to the detection module.

8. The radio frequency front-end module according to any one of claims 2-4, characterized in that, The radio frequency front-end module includes multiple power amplification modules, and each power amplification module is configured with a signal coupling module. The multiple power amplification modules operate in different frequency bands. The output terminals of multiple signal coupling modules are connected to the input terminals of the signal bus, and the output terminals of the signal bus are connected to the detection module.

9. The radio frequency front-end module according to any one of claims 2-4, characterized in that, The radio frequency front-end module also includes a filtering module and an antenna module, with the filtering module connected between the power amplifier module and the antenna module.

10. The radio frequency front-end module according to any one of claims 2-4, characterized in that, The RF front-end module also includes a frequency selection module, which is connected between the power amplifier module and the filter module.

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