Radio frequency power amplifier and radio frequency front-end module

Abstract

The invention discloses a radio frequency power amplifier which comprises a first power amplification circuit, a second power amplification circuit and a voltage synthesis network, the voltage synthesis network comprises a first transformer, a second transformer and a first capacitor unit, the first transformer comprises a first winding and a second winding, and the second transformer comprises a second winding and a third winding. The second transformer comprises a third winding and a fourth winding; the first power amplification circuit is connected with the first winding, the second power amplification circuit is connected with the third winding, a first end of the second winding is connected to a signal output end, a second end of the second winding is connected with a first end of the fourth winding, and a second end of the fourth winding is connected to a grounding end; wherein the first capacitor unit is connected in parallel with at least part of the coil of the second winding; therefore, the problem of overlarge loss caused by poor balance of the radio frequency power amplifier can be solved.

Description

Technical Field

[0001] The present application relates to the field of radio frequency technology, and in particular to a radio frequency power amplifier and a radio frequency front-end module. Background Art

[0002] RF front-end modules are widely used in the field of wireless communications. As the core unit of RF front-end modules, the performance of RF power amplifiers has a great impact on the signal output indicators of RF front-end modules. The design indicators of RF power amplifiers usually include output power, loss, efficiency, gain, bandwidth, and linearity. In particular, its loss and efficiency have always been the focus of attention. The power loss of RF power amplifiers has become an important performance indicator to measure the operating efficiency of power amplifiers, and plays a vital role in the entire communication system.

[0003] Application Contents

[0004] The embodiments of the present application provide a radio frequency power amplifier and a radio frequency front-end module to solve the problem of excessive loss of the radio frequency power amplifier.

[0005] A radio frequency power amplifier comprises a first power amplifier circuit, a second power amplifier circuit and a voltage synthesis network, wherein the voltage synthesis network comprises a first transformer, a second transformer and a first capacitor unit, wherein the first transformer comprises a first winding and a second winding, and the second transformer comprises a third winding and a fourth winding; the first power amplifier circuit is connected to the first winding, the second power amplifier circuit is connected to the third winding, the first end of the second winding is connected to a signal transmission end, the second end of the second winding is connected to the first end of the fourth winding, and the second end of the fourth winding is connected to a ground end; wherein the first capacitor unit is connected in parallel with at least part of the coil of the second winding.

[0006] Further, the output end of the first power amplifier circuit is connected to the first winding, the output end of the second power amplifier circuit is connected to the third winding, and the first capacitor unit is configured to balance the impedance between the output end of the first power amplifier circuit and the output end of the second power amplifier circuit;

[0007] Alternatively, the input end of the first power amplifier circuit is connected to the first winding, the input end of the second power amplifier circuit is connected to the third winding, and the first capacitor unit is configured to balance the impedance between the input end of the first power amplifier circuit and the input end of the second power amplifier circuit.

[0008] Further, the output end of the first power amplifier circuit is connected to the first winding, the output end of the second power amplifier circuit is connected to the third winding, and the first capacitor unit is configured to make the output end impedance of the first power amplifier circuit and the output end impedance of the second power amplifier circuit the same;

[0009] Alternatively, the input end of the first power amplifier circuit is connected to the first winding, the input end of the second power amplifier circuit is connected to the third winding, and the first capacitor unit is configured to make the input end impedance of the first power amplifier circuit and the input end impedance of the second power amplifier circuit the same.

[0010] Further, the first capacitor unit is configured to compensate for the capacitance value of the equivalent parasitic capacitance equivalently transformed by the second transformer at the first end of the fourth winding.

[0011] Further, the capacitance value of the first capacitor unit ranges from (0*CP2, 2*CP2), wherein CP2 is the capacitance value of the equivalent parasitic capacitance equivalently transformed by the second transformer at the first end of the fourth winding.

[0012] Furthermore, the capacitance value of the first capacitor unit is in the range of (0, 20 pF).

[0013] Further, the first power amplifier circuit includes a first power amplifier transistor, the second power amplifier circuit includes a second power amplifier transistor, the first power amplifier transistor is connected to the first end of the first winding, the second end of the first winding is connected to the ground terminal or the power supply terminal, the second power amplifier transistor is connected to the first end of the third winding, and the second end of the third winding is connected to the ground terminal or the power supply terminal.

[0014] Further, a difference between a phase of the first radio frequency signal at the first end of the first winding and a phase of the second radio frequency signal at the first end of the third winding is in a range of [0°, 10°].

[0015] Further, the first power amplifier circuit includes a first power amplifier transistor and a third power amplifier transistor, the second power amplifier circuit includes a second power amplifier transistor and a fourth power amplifier transistor, the first power amplifier transistor is connected to the first end of the first winding, the third power amplifier transistor is connected to the second end of the first winding, the second power amplifier transistor is connected to the first end of the third winding, and the fourth power amplifier transistor is connected to the second end of the third winding.

[0016] Further, the difference range between the phase of the first RF signal at the first end of the first winding and the phase of the second RF signal at the first end of the third winding is [0°, 10°], and the difference range between the phase of the third RF signal at the second end of the first winding and the phase of the fourth RF signal at the second end of the third winding is [0°, 10°].

[0017] Further, the second winding includes a first coil segment and a second coil segment connected in series, the fourth winding includes a third coil segment and a fourth coil segment connected in series, the first end of the first coil segment is connected to the signal output end, the second end of the first coil segment is connected to the first end of the second coil segment, the second end of the second coil segment is connected to the first end of the third coil segment, the second end of the third coil segment is connected to the first end of the fourth coil segment, and the second end of the fourth coil segment is grounded; wherein the first capacitor unit is connected in parallel with the first coil segment.

[0018] Further, the first power amplifying transistor, the third power amplifying transistor, the second power amplifying transistor and the fourth power amplifying transistor are all BJT transistors, including a base, a collector and an emitter;

[0019] The base of the first power amplifier transistor receives an input first RF signal, the collector of the first power amplifier transistor is connected to the first end of the first winding, and the emitter of the first power amplifier transistor is grounded; the base of the third power amplifier transistor receives an input third RF signal, the collector of the third power amplifier transistor is connected to the second end of the first winding, and the emitter of the third power amplifier transistor is grounded; the base of the second power amplifier transistor receives an input second RF signal, the collector of the second power amplifier transistor is connected to the first end of the third winding, and the emitter of the second power amplifier transistor is grounded; the base of the fourth power amplifier transistor receives an input fourth RF signal, the collector of the fourth power amplifier transistor is connected to the second end of the third winding, and the emitter of the fourth power amplifier transistor is grounded;

[0020] Alternatively, the base of the first power amplifier transistor is connected to the first end of the first winding, the collector of the first power amplifier transistor outputs a first radio frequency signal, and the emitter of the first power amplifier transistor is grounded; the base of the third power amplifier transistor is connected to the second end of the first winding, the collector of the third power amplifier transistor outputs a third radio frequency signal, and the emitter of the third power amplifier transistor is grounded; the base of the second power amplifier transistor is connected to the first end of the third winding, the collector of the second power amplifier transistor outputs a second radio frequency signal, and the emitter of the second power amplifier transistor is grounded; the base of the fourth power amplifier transistor is connected to the second end of the third winding, the collector of the fourth power amplifier transistor outputs a fourth radio frequency signal, and the emitter of the fourth power amplifier transistor is grounded.

[0021] Further, the first transformer also includes a fifth winding, and the second transformer also includes a sixth winding, the fifth winding and the sixth winding are connected in series, the fifth winding is coupled with the first winding and the second winding, the sixth winding is coupled with the third winding and the fourth winding, and the second end of the fourth winding is connected to the ground terminal through the fifth winding and the sixth winding connected in series.

[0022] Further, the second end of the fourth winding is connected to the second end of the sixth winding, the first end of the sixth winding is connected to the second end of the fifth winding, and the first end of the fifth winding is grounded; or, the second end of the fourth winding is connected to the first end of the fifth winding, the second end of the fifth winding is connected to the first end of the sixth winding, and the second end of the sixth winding is grounded.

[0023] A radio frequency front-end module comprises a substrate, and a first chip and a second chip arranged on the substrate, wherein the first chip comprises a first power amplifier circuit and a second power amplifier circuit, the second chip comprises a first transformer, a second transformer and a first capacitor unit, the first transformer comprises a first winding and a second winding, the second transformer comprises a third winding and a fourth winding, the first power amplifier circuit is connected to a first pad of the first chip, the first pad is connected to a second pad of the second chip, the second pad is connected to the first winding, the second power amplifier circuit is connected to a third pad of the first chip, the third pad is connected to a fourth pad of the second chip, and the fourth pad is connected to the third winding; a first end of the second winding is connected to a signal output end, a second end of the second winding is connected to a first end of the fourth winding, and a second end of the fourth winding is connected to a ground end; wherein the first capacitor unit is connected in parallel with at least part of the coil of the second winding.

[0024] Furthermore, the first chip is a heterojunction bipolar transistor chip, and the second chip is an integrated product development chip.

[0025] A radio frequency front-end module, the radio frequency front-end module comprising a substrate, and a first chip, a first transformer, a second transformer and a first capacitor unit arranged on the substrate, the first chip comprising a first power amplifier circuit and a second power amplifier circuit, the first transformer comprising a first winding and a second winding, the second transformer comprising a third winding and a fourth winding, the first power amplifier circuit being connected to a first pad of the first chip, the first pad being connected to a second pad of the substrate, the second pad being connected to the first winding, the second power amplifier circuit being connected to a third pad of the first chip, the third pad being connected to a fourth pad of the substrate, and the fourth pad being connected to the third winding; a first end of the second winding being connected to a signal output end, a second end of the second winding being connected to a first end of the fourth winding, and a second end of the fourth winding being connected to a ground end; wherein the first capacitor unit is connected in parallel with at least part of the coil of the second winding.

[0026] Furthermore, the first capacitor unit is a chip capacitor unit.

[0027] The present application provides a radio frequency power amplifier, comprising a first power amplifier circuit, a second power amplifier circuit and a voltage synthesis network, wherein the voltage synthesis network comprises a first transformer, a second transformer and a first capacitor unit, wherein the first transformer comprises a first winding and a second winding, and the second transformer comprises a third winding and a fourth winding; the first power amplifier circuit is connected to the first winding, the second power amplifier circuit is connected to the third winding, the first end of the second winding is connected to a signal output end, the second end of the second winding is connected to the first end of the fourth winding, and the second end of the fourth winding is connected to a ground end; wherein the first capacitor unit is connected in parallel with at least part of the coil of the second winding; thereby improving the balance problem caused by the inconsistency of the voltage amplitude and phase between the two ends of the second winding and the two ends of the fourth winding, thereby solving the problem of excessive loss caused by poor balance of the voltage synthesis network in the radio frequency power amplifier, and optimizing the overall performance of the radio frequency power amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0029] Figure 1 is a circuit diagram of a radio frequency power amplifier in one embodiment of the present application;

[0030] Figure 2 is another circuit diagram of a radio frequency power amplifier in one embodiment of the present application;

[0031] Figure 3 is another circuit diagram of a radio frequency power amplifier in one embodiment of the present application;

[0032] Figure 4 is another circuit diagram of a radio frequency power amplifier in one embodiment of the present application;

[0033] Figure 5 is another circuit diagram of a radio frequency power amplifier in one embodiment of the present application;

[0034] Figure 6 is another circuit diagram of a radio frequency power amplifier in one embodiment of the present application;

[0035] Figure 7 is another circuit diagram of a radio frequency power amplifier in one embodiment of the present application;

[0036] Figure 8 is another circuit diagram of a radio frequency front-end module in one embodiment of the present application;

[0037] Fig. 9 is another circuit diagram of a radio frequency front-end module in one embodiment of the present application;

[0038] Fig.10 It is a simulation diagram of a radio frequency power amplifier / radio frequency front-end module in one embodiment of the present application;

[0039] Fig.11 It is a simulation diagram of a radio frequency power amplifier / radio frequency front-end module in one embodiment of the present application;

[0040] Fig.12 This is a simulation diagram of the RF power amplifier / RF front-end module in one embodiment of the present application.

[0041] In the figure, 10, a first power amplifier circuit; 20, a second power amplifier circuit; a first transformer, 50; a second transformer, 60; 70, a first capacitor unit; 11, a first power amplifier transistor; 12, a second power amplifier transistor; 13, a third power amplifier transistor; 14, a fourth power amplifier transistor; S11, a first winding; S12, a second winding; S13, a third winding; S14: a fourth winding; 100, a first chip; 200, a second chip; 300, a substrate. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] It should be understood that the present application can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and fully convey the scope of the present application to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0044] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to or coupled to other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on, directly adjacent to, directly connected to or directly coupled to other elements or layers, there are no intervening elements or layers. It should be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below may be represented as a second element, component, region, layer or part.

[0045] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that the spatially relative terms are intended to include different orientations of the device in use and operation in addition to the orientations shown in the figures. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0046] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present application. When used herein, the singular forms "a", "an" and " / the" are also intended to include plural forms, unless the context clearly indicates another way. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0047] In order to thoroughly understand the present application, detailed structures and steps will be presented in the following description to illustrate the technical solution proposed by the present application. The preferred embodiments of the present application are described in detail below, but in addition to these detailed descriptions, the present application may also have other implementation methods.

[0048] A radio frequency power amplifier, such as Figure 1 As shown, a first power amplifier circuit 10, a second power amplifier circuit 20 and a voltage synthesis network, the voltage synthesis network includes a first transformer 50, a second transformer 60 and a first capacitor unit 70, the first transformer 50 includes a first winding S11 and a second winding S12, the second transformer 60 includes a third winding S13 and a fourth winding S14; the first power amplifier circuit 10 is connected to the first winding S11, the second power amplifier circuit 20 is connected to the third winding S13, the first end of the second winding S12 is connected to the signal transmission end, the second end of the second winding S12 is connected to the first end of the fourth winding S14, and the second end of the fourth winding S14 is connected to the ground end; wherein the first capacitor unit 70 is connected in parallel with at least part of the coil of the second winding S12.

[0049] The first power amplifier circuit 10 may be any type of amplifier circuit, such as a single-ended power amplifier circuit, a differential power amplifier circuit, a Doherty power amplifier circuit, a balanced power amplifier circuit, etc. Similarly, the second power amplifier circuit 20 may be any type of amplifier circuit, such as a single-ended power amplifier circuit, a differential power amplifier circuit, a Doherty power amplifier circuit, etc.

[0050] In at least one embodiment, the voltage synthesis network includes a first transformer 50, a second transformer 60 and a first capacitor unit 70. The first transformer 50 is connected to the first winding S11 of the first power amplifier circuit 10, the second transformer 60 is connected to the third winding S13 of the second power amplifier circuit 20, and the second winding S12 of the first transformer 50 is connected to the fourth winding S14 of the second transformer 60, so as to synthesize at least one first signal output by the first power amplifier circuit 10 and at least one second signal output by the second power amplifier circuit 10 by voltage synthesis, and finally form an output signal to be output to the signal transmission end (for example: signal output end). Alternatively, an input signal of the signal transmission end (for example: signal input end) is divided into at least one first signal transmitted to the first power amplifier circuit and at least one second signal transmitted to the second power amplifier circuit.

[0051] In at least one embodiment, since the voltage at the first end of the first winding S11 of the first transformer is the same as the voltage at the first end of the third winding S13 of the second transformer, the voltage at the first end of the second winding S12 is different from the voltage at the first end of the fourth winding S14. Specifically, since the equivalent parasitic capacitance of the second transformer S13 is equivalently transformed at the first end of the fourth winding S14, the current I1 of the second winding S12 of the first transformer is greater than the current I2 of the fourth winding S14 of the second transformer, so the voltage amplitude and phase at both ends of the second winding are inconsistent with those at both ends of the fourth winding, thereby affecting the balance of the RF power amplifier.

[0052] To this end, this embodiment connects a first capacitor unit 70, and the first capacitor unit 70 is connected in parallel with at least part of the coil of the second winding S12, so as to compensate for the equivalent parasitic capacitance equivalently transformed by the second transformer S13 at the first end of the fourth winding S14, thereby improving the balance problem caused by the inconsistent voltage amplitude and phase between the two ends of the second winding and the two ends of the fourth winding, thereby solving the problem of excessive loss caused by poor balance of the voltage synthesis network in the RF power amplifier, and optimizing the overall performance of the RF power amplifier.

[0053] Among them, the first capacitor unit 70 is connected in parallel with at least part of the coil of the second winding S12, which can be understood as the first capacitor unit 70 is connected in parallel with any section of the coil of the second winding, and the coil can be a complete coil of the second winding or a partial coil. The first capacitor element can be a physical capacitor element or a specific structure equivalent to a capacitor element. The capacitance value of the first capacitor element is related to the capacitance value CP2 of the equivalent parasitic capacitance equivalently transformed by the second transformer S13 at the first end of the fourth winding S14. Specifically, the capacitance value of the first capacitor element is positively correlated with the capacitance value CP2 of the equivalent parasitic capacitance equivalently transformed by the second transformer S13 at the first end of the fourth winding S14, that is, the larger the capacitance value CP2 of the equivalent parasitic capacitance equivalently transformed by the second transformer S13 at the first end of the fourth winding S14, the larger the capacitance value CP2 of the first capacitor element.

[0054] It should be noted that this embodiment does not specifically limit the specific implementation of the first transformer and the second transformer. The first transformer and the second transformer may be two identical transformers or two different transformers. The first transformer and the second transformer may be single-end to single-end transformers, single-end to double-end transformers, or double-end to single-end transformers.

[0055] The first winding and the second winding in the first transformer can be wound on the same metal layer or different metal layers, and the third winding and the fourth winding in the second transformer can be wound on the same metal layer or different metal layers. The turns ratio of the first winding and the second winding and the turns ratio of the third winding and the fourth winding can be the same or different.

[0056] As a preferred example, the specific implementation methods of the first transformer and the second transformer are the same. For example, the turns ratio of the first winding and the second winding is the same as the turns ratio of the third winding and the fourth winding, and the winding method of the first winding and the second winding is the same as the winding method of the third winding and the fourth winding; thereby, the balance of the RF power amplifier can be further improved, thereby reducing the power loss of the RF power amplifier.

[0057] See below Fig.10 As shown in the figure, it is a simulation diagram without adding the first capacitor unit in the prior art, wherein the lower Fig.10 The ordinate of the first graph is the imaginary impedance, and the abscissa is the operating frequency. The ordinate of the second graph is the real impedance, and the abscissa is the operating frequency. a is the curve of the first power amplifier circuit, and b is the curve of the second power amplifier circuit. Fig.10It can be seen that the imaginary impedance of the first power amplifier circuit and the imaginary impedance of the second power amplifier circuit are different within a wide bandwidth, and the real impedance of the first power amplifier circuit and the real impedance of the second power amplifier circuit are also different within a wide bandwidth, resulting in poor balance of the RF power amplifier.

[0058] See below Fig.11 As shown, it is a simulation diagram of the present application with the first capacitor unit added. Fig.10 The ordinate of the first graph is the real impedance, and the abscissa is the operating frequency. The ordinate of the second graph is the imaginary impedance, and the abscissa is the operating frequency. a is the curve of the first power amplifier circuit, and b is the curve of the second power amplifier circuit. Fig.11 It can be seen that the imaginary impedance and the real impedance of the first power amplifier circuit overlap with the imaginary impedance and the real impedance of the second power amplifier circuit within a wide bandwidth, that is, the imaginary impedance and the real impedance of the first power amplifier circuit are the same as the imaginary impedance and the real impedance of the second power amplifier circuit within a wide bandwidth, thereby improving the balance of the RF power amplifier.

[0059] See below Fig.12 As shown in FIG. 1 , it is a simulation diagram of the power efficiency of the RF power amplifier in a wide frequency band, wherein M1 is a curve in which the first capacitor unit is added in the present application, and N1 is a curve in which the first capacitor unit is not added in the prior art. Fig.12 It can be seen that the power efficiency of the present application with the first capacitor unit added is significantly higher than the power efficiency of the prior art without the first capacitor unit added.

[0060] In this embodiment, the RF power amplifier includes a first power amplifier circuit, a second power amplifier circuit and a voltage synthesis network, the voltage synthesis network includes a first transformer, a second transformer and a first capacitor unit, the first transformer includes a first winding and a second winding, the second transformer includes a third winding and a fourth winding; the first power amplifier circuit is connected to the first winding, the second power amplifier circuit is connected to the third winding, the first end of the second winding is connected to the signal output end, the second end of the second winding is connected to the first end of the fourth winding, and the second end of the fourth winding is connected to the ground end; wherein the first capacitor unit is connected in parallel with at least part of the coil of the second winding; thereby improving the balance problem caused by the inconsistency of the voltage amplitude and phase between the two ends of the second winding and the two ends of the fourth winding, thereby solving the problem of excessive loss caused by poor balance of the voltage synthesis network in the RF power amplifier, and optimizing the overall performance of the RF power amplifier.

[0061] In a specific embodiment, the output end of the first power amplifier circuit 10 is connected to the first winding S11, the output end of the second power amplifier circuit 20 is connected to the third winding S13, and the first capacitor unit 70 is configured to balance the impedance between the output end of the first power amplifier circuit 10 and the output end of the second power amplifier circuit 20.

[0062] In at least one embodiment, refer to Figure 1 As shown, the first winding S11 of the first transformer 50 is connected to the output end of the first power amplifier circuit 10, and the third winding S13 of the second transformer 60 is connected to the output end of the second power amplifier circuit 20. The first transformer 50 and the second transformer 60 synthesize at least one first signal output by the first power amplifier circuit 10 and at least one second signal output by the second power amplifier circuit 10 by voltage synthesis, and finally form a radio frequency output signal to be output to the signal transmission end. Since the first capacitor unit and at least part of the coils of the second winding in the first transformer are connected in parallel, the impedance balance between the output end of the first power amplifier circuit and the output end of the second power amplifier circuit is achieved by reasonably configuring the capacitance value of the first capacitor unit.

[0063] In at least one embodiment, refer to Figure 2 As shown, the input end of the first power amplifier circuit 10 is connected to the first winding S11, the input end of the second power amplifier circuit 20 is connected to the third winding S13, and the first capacitor unit 70 is configured to balance the impedance between the input end of the first power amplifier circuit 10 and the input end of the second power amplifier circuit 20.

[0064] Specifically, the first winding S11 of the first transformer is connected to the input end of the first power amplifier circuit, the third winding S13 of the second transformer is connected to the input end of the second power amplifier circuit, and the first transformer and the second transformer convert a radio frequency input signal at the radio frequency input end into at least one first signal and at least one second signal by voltage synthesis, and transmit them to the first power amplifier circuit 10 and the second power amplifier circuit 10 respectively. Since the first capacitor unit and at least part of the coils of the second winding in the first transformer are connected in parallel, the impedance balance between the input end of the first power amplifier circuit and the input end of the second power amplifier circuit is achieved by reasonably configuring the capacitance value of the first capacitor unit.

[0065] In at least one embodiment, the output end of the first power amplifier circuit 10 is connected to the first winding S11, the output end of the second power amplifier circuit 20 is connected to the third winding S13, and the first capacitor unit 70 is configured to make the output end impedance of the first power amplifier circuit 10 and the output end impedance of the second power amplifier circuit 20 the same.

[0066] Specifically, by reasonably configuring the capacitance value of the first capacitor unit 70, the larger the capacitance value CP2 of the equivalent parasitic capacitance equivalently transformed by the second transformer S13 at the first end of the fourth winding S14, the larger the capacitance value of the first capacitor element; by making the capacitance value of the first capacitor unit the same as the capacitance value of the equivalent parasitic capacitance equivalently transformed by the second transformer S13 at the first end of the fourth winding S14, the impedance between the output end of the first power amplifier circuit and the output end of the second power amplifier circuit is made the same.

[0067] In at least one embodiment, the input end of the first power amplifier circuit is connected to the first winding, the input end of the second power amplifier circuit is connected to the third winding, and the first capacitor unit is configured to make the input impedance of the first power amplifier circuit the same as the input impedance of the second power amplifier circuit. Specifically, by reasonably configuring the capacitance value of the first capacitor unit, the larger the capacitance value CP2 of the equivalent parasitic capacitance equivalently transformed by the second transformer S13 at the first end of the fourth winding S14, the larger the capacitance value of the first capacitor element; by making the capacitance value of the first capacitor unit the same as the capacitance value of the equivalent parasitic capacitance equivalently transformed by the second transformer S13 at the first end of the fourth winding S14, the impedance between the input end of the first power amplifier circuit and the input end of the second power amplifier circuit is made the same.

[0068] In a specific embodiment, the first capacitor unit 70 is configured to compensate for the capacitance value of the equivalent parasitic capacitance equivalently transformed by the second transformer at the first end of the fourth winding.

[0069] In at least one embodiment, since the equivalent parasitic capacitance of the second transformer S13 is equivalently transformed at the first end of the fourth winding S14, the current I1 of the second winding S12 of the first transformer is greater than the current I2 of the fourth winding S14 of the second transformer, so the voltage difference between the first winding S11 and the second winding S12 is greater than the voltage difference between the third winding S13 and the fourth winding S14, thereby affecting the balance of the RF power amplifier. In view of this, the present application connects a first capacitor unit in parallel at the second winding S12 of the first transformer, and the first capacitor unit is configured to compensate for the capacitance value of the equivalent parasitic capacitance equivalently transformed by the second transformer S13 at the first end of the fourth winding S14, and reasonably configures the capacitance value of the first capacitor unit, thereby improving the balance of the RF power amplifier.

[0070] In a specific embodiment, the capacitance value of the first capacitor unit ranges from (0*CP2, 2*CP2), wherein CP2 is the capacitance value of the equivalent parasitic capacitance equivalently transformed by the second transformer at the first end of the fourth winding.

[0071] In at least one embodiment, the capacitance value of the first capacitor unit is associated with the capacitance value of the equivalent parasitic capacitance equivalently transformed by the second transformer at the first end of the fourth winding, and the capacitance value range of the first capacitor unit is (0*CP2, 2*CP2), wherein CP2 is the capacitance value of the equivalent parasitic capacitance equivalently transformed by the second transformer at the first end of the fourth winding, that is, the capacitance value of the first capacitor unit can be less than the capacitance value of the equivalent parasitic capacitance equivalently transformed by the second transformer at the first end of the fourth winding, and can also be greater than the capacitance value of the equivalent parasitic capacitance equivalently transformed by the second transformer at the first end of the fourth winding, but the capacitance value of the first capacitor unit must satisfy (0*CP2, 2*CP2). The equivalent parasitic capacitance CP2 generated by the second transformer can be obtained by measurement. As an example, the first end and the second end of the primary winding of the second transformer are connected in parallel and connected to the measurement port Vin, and Vin=1V, and the first end and the second end of the secondary winding of the second transformer are connected in parallel and grounded, so that the current input to the two ends of the primary winding of the second transformer can be measured, and then the equivalent parasitic capacitance Cp generated by the second transformer can be calculated through the formula Cp=2*pi*f*Vin / I in.

[0072] In at least one implementation, when the capacitance value of the first capacitor unit is equal to the capacitance value of the equivalent parasitic capacitance equivalently transformed by the first end of the fourth winding, the output impedance of the first power amplifier circuit is the same as the output impedance of the second power amplifier circuit, and the balance of the RF power amplifier is optimal. As an example, if the equivalent parasitic capacitance CP2 generated by the second transformer is 1pF, the capacitance value of the first capacitor unit is 1pF.

[0073] In at least one embodiment, the equivalent parasitic capacitance CP2 generated by the second transformer has a value in the range of greater than 0 pF and less than 10 pF.

[0074] It can be understood that the capacitance value of the first capacitor unit is associated with the equivalent parasitic capacitance CP2 generated by the second transformer. The larger the equivalent parasitic capacitance CP2 generated by the second transformer is, the larger the capacitance value of the first capacitor unit is.

[0075] In at least one embodiment, the capacitance value Cp of the first capacitor unit is in the range of (0, 20 pF). Optionally, the capacitance value of the first capacitor unit may be 3 pF, 5 pF, 7 pF, 14 pF or 18 pF, etc.

[0076] In a specific embodiment, refer to the following Figure 3 As shown, the first power amplifier circuit 10 includes a first power amplifier transistor 11, and the second power amplifier circuit 20 includes a second power amplifier transistor 20. The first power amplifier transistor 11 is connected to a first end of the first winding S11, and a second end of the first winding S11 is connected to a ground terminal or a power supply terminal. The second power amplifier transistor 20 is connected to a first end of the third winding S13, and a second end of the third winding S13 is connected to a ground terminal or a power supply terminal.

[0077] Among them, when the second end of the first winding S11 is connected to the power supply end, and the second end of the third winding S13 is connected to the power supply end, the first power supply voltage output by the power supply source is transmitted to the first power amplifier transistor 11 through the first winding S11 of the power supply end to power the first power amplifier transistor 11, and the second power supply voltage output by the power supply source is transmitted to the second power amplifier transistor 20 through the third winding S13 of the power supply end to power the second power amplifier transistor 20, without the need for additional access to the power supply inductor connected to the power supply end, which can reduce the occupied area of ​​the RF power amplifier and optimize the integration of the RF power amplifier. It should be noted that, since the capacitor has the function of isolating DC and passing AC, when the second end of the first winding S11 is connected to the power supply end, and the second end of the third winding S13 is connected to the power supply end, there should be no capacitor element in the series path between the first power amplifier transistor 11 and the first winding S11, and similarly, there should be no capacitor element in the series path between the second power amplifier transistor 12 and the third winding S13.

[0078] In at least one embodiment, the first power amplifier circuit and the second power amplifier circuit are both single-ended power amplifier circuits, and the first transformer and the second transformer are both single-ended to single-ended transformers. The first power amplifier circuit includes a first power amplifier transistor, and the second power amplifier circuit includes a second power amplifier transistor, the first power amplifier transistor is connected to the first end of the first winding, the second end of the first winding is connected to the ground end or the power supply end, the second power amplifier transistor is connected to the first end of the third winding, the second end of the third winding is connected to the ground end or the power supply end, and the first transformer and the second transformer work together to convert the first RF signal in the first power amplifier transistor and the second RF signal in the second power amplifier transistor into one RF signal.

[0079] Among them, the first power amplifier transistor can be a BJT tube or a MOS tube, and the second power amplifier transistor can be a BJT tube or a MOS tube. This embodiment does not specifically limit the types of the first power amplifier transistor and the second power amplifier transistor.

[0080] In at least one embodiment, a difference between a phase of the first RF signal at the first end of the first winding S11 and a phase of the second RF signal at the first end of the third winding S13 is in a range of [0°, 10°].

[0081] In at least one embodiment, the phase of the first RF signal transmitted in the first power amplifier transistor 11 and the phase of the second RF signal transmitted in the second power amplifier transistor 12 are in the same phase. The first power amplifier transistor is connected to the first end of the first winding, and the second power amplifier transistor is connected to the first end of the third winding. Therefore, the phase of the first RF signal at the first end of the first winding and the phase of the second RF signal at the first end of the third winding are also in the same phase. In this embodiment, the difference range between the phase of the first RF signal at the first end of the first winding S11 and the phase of the second RF signal at the first end of the third winding S13 is [0°, 10°]. For example: the phase of the first RF signal at the first end of the first winding is 180°, and the phase of the second RF signal at the first end of the third winding is 179°. Alternatively, the phase of the first RF signal at the first end of the first winding is 0°, and the phase of the second RF signal at the first end of the third winding is 2°.

[0082] In at least one embodiment, refer to Figure 4 As shown, the first power amplifier circuit 10 includes a first power amplifier transistor 11 and a third power amplifier transistor 13, and the second power amplifier circuit 20 includes a second power amplifier transistor 12 and a fourth power amplifier transistor 14, the first power amplifier transistor 11 is connected to the first end of the first winding S11, the third power amplifier transistor 13 is connected to the second end of the first winding S11, the second power amplifier transistor 12 is connected to the first end of the third winding S13, and the fourth power amplifier transistor 14 is connected to the second end of the third winding S13.

[0083] In at least one embodiment, the first power amplifier circuit and the second power amplifier circuit are both differential power amplifier circuits. The first transformer and the second transformer are both differential to single-ended or single-ended to differential or differential to single-ended transformers. The first power amplifier transistor 11 is connected to the first end of the first winding S11, the third power amplifier transistor 13 is connected to the second end of the first winding S11, the second power amplifier transistor 12 is connected to the first end of the third winding S13, and the fourth power amplifier transistor 14 is connected to the second end of the third winding S13. The first transformer and the second transformer work together to convert the first RF signal in the first power amplifier transistor, the third RF signal in the third power amplifier transistor, the second RF signal in the second power amplifier transistor, and the fourth RF signal in the fourth power amplifier transistor into one RF signal.

[0084] Among them, the first power amplifier transistor, the second power amplifier transistor, the second power amplifier transistor and the fourth power amplifier transistor can be a BJT tube or a MOS tube. This embodiment does not specifically limit the types of the first power amplifier transistor, the second power amplifier transistor, the second power amplifier transistor and the fourth power amplifier transistor.

[0085] In at least one embodiment, the phase difference between the first RF signal at the first end of the first winding and the phase difference between the second RF signal at the first end of the third winding is in the range of [0°, 10°], and the phase difference between the third RF signal at the second end of the first winding and the fourth RF signal at the second end of the third winding is in the range of [0°, 10°].

[0086] In at least one embodiment, since the first power amplifier circuit is a differential amplifier circuit, the first power amplifier circuit includes a first power amplifier transistor and a third power amplifier transistor. Therefore,

[0087] The first RF signal transmitted in the first power amplifier transistor and the third RF signal transmitted in the third power amplifier transistor are two signals with opposite phases. Since the first power amplifier transistor is connected to the first end of the first winding and the third power amplifier transistor is connected to the second end of the first winding, the difference range of the phase of the first RF signal at the first end of the first winding and the phase of the third RF signal at the second end of the first winding is [170°, 190°]. Similarly, since the second power amplifier circuit is a differential amplifier circuit, the second power amplifier circuit includes a second power amplifier transistor and a fourth power amplifier transistor. Therefore, the second RF signal transmitted in the second power amplifier transistor and the fourth RF signal transmitted in the fourth power amplifier transistor are two signals with opposite phases. Since the second power amplifier transistor is connected to the first end of the third winding and the fourth power amplifier transistor is connected to the second end of the second winding, the difference range of the phase of the second RF signal at the first end of the second winding and the phase of the fourth RF signal at the second end of the second winding is [170°, 190°].

[0088] In at least one embodiment, the phase of the first RF signal transmitted in the first power amplifying transistor and the phase of the second RF signal transmitted in the second power amplifying transistor are in the same direction. Since the first power amplifying transistor is connected to the first end of the first winding and the second power amplifying transistor is connected to the first end of the third winding, the phase of the first RF signal at the first end of the first winding and the phase of the second RF signal at the first end of the third winding are close. In this embodiment, the difference range between the phase of the first RF signal at the first end of the first winding and the phase of the second RF signal at the first end of the third winding is [0°, 10°]. Similarly, the phase of the third RF signal transmitted in the third power amplifier transistor and the phase of the fourth RF signal transmitted in the fourth power amplifier transistor are in the same direction. Since the third power amplifier transistor is connected to the second end of the first winding and the fourth power amplifier transistor is connected to the second end of the third winding, the phase of the third RF signal at the second end of the first winding and the phase of the fourth RF signal at the second end of the third winding are close. In this embodiment, the difference range between the phase of the third RF signal at the second end of the first winding and the phase of the fourth RF signal at the second end of the third winding is [0°, 10°].

[0089] See below Figure 5 As shown, the second winding 12 includes a first coil segment and a second coil segment connected in series, the fourth winding 14 includes a third coil segment and a fourth coil segment connected in series, the first end of the first coil segment is connected to the signal output end, the second end of the first coil segment is connected to the first end of the second coil segment, the second end of the second coil segment is connected to the first end of the third coil segment, the second end of the third coil segment is connected to the first end of the fourth coil segment, and the second end of the fourth coil segment is grounded; wherein the first capacitor unit 70 is connected in parallel with the first coil segment.

[0090] Among them, the first coil segment and the second coil segment can be a complete coil segment or two separate coil segments. When the first coil segment and the second coil segment are two separate coil segments, the first coil segment and the second coil segment can be directly connected or connected through other components. Similarly, the third coil segment and the fourth coil segment can be a complete coil segment or two separate coil segments. When the third coil segment and the fourth coil segment are two separate coil segments, the third coil segment and the fourth coil segment can be directly connected or connected through other components.

[0091] The first winding is coupled with the first coil segment and the second coil segment, and the third winding is coupled with the third coil segment and the fourth coil segment. In this embodiment, the first capacitor unit is connected in parallel with the first coil segment, thereby improving the balance problem caused by the voltage difference between the first winding and the second winding being greater than the voltage difference between the third winding and the fourth winding, thereby solving the problem of excessive loss of the RF power amplifier due to poor balance, and optimizing the overall performance of the RF power amplifier.

[0092] In another specific embodiment, the first capacitor unit 70 may be connected in parallel with the first coil segment and the second coil segment, or the first capacitor unit may be connected in parallel with the first coil segment, the second coil segment and the third coil segment, or the first capacitor unit 70 may be connected in parallel with the second coil segment. Similarly, the balance problem caused by the voltage difference between the first winding S11 and the second winding S12 being greater than the voltage difference between the third winding S13 and the fourth winding S14 can be improved, thereby solving the problem of excessive loss of the RF power amplifier due to poor balance, and improving the overall performance of the RF power amplifier.

[0093] In a specific embodiment, the first power amplifier transistor 11, the third power amplifier transistor 13, the second power amplifier transistor 12 and the fourth power amplifier transistor 14 are all BJT transistors, including a base, a collector and an emitter.

[0094] In at least one embodiment, the base of the first power amplifier transistor receives an input first RF signal, the collector of the first power amplifier transistor is connected to the first end of the first winding, and the emitter of the first power amplifier transistor is grounded; the base of the third power amplifier transistor receives an input third RF signal, the collector of the third power amplifier transistor is connected to the second end of the first winding, and the emitter of the third power amplifier transistor is grounded; the base of the second power amplifier transistor receives an input second RF signal, the collector of the second power amplifier transistor is connected to the first end of the third winding, and the emitter of the second power amplifier transistor is grounded; the base of the fourth power amplifier transistor receives an input fourth RF signal, the collector of the fourth power amplifier transistor is connected to the second end of the third winding, and the emitter of the fourth power amplifier transistor is grounded.

[0095] Alternatively, in at least one embodiment, the base of the first power amplifier transistor is connected to the first end of the first winding, the collector of the first power amplifier transistor outputs a first RF signal, and the emitter of the first power amplifier transistor is grounded; the base of the third power amplifier transistor is connected to the second end of the first winding, the collector of the third power amplifier transistor outputs a third RF signal, and the emitter of the third power amplifier transistor is grounded; the base of the second power amplifier transistor is connected to the first end of the third winding, the collector of the second power amplifier transistor outputs a second RF signal, and the emitter of the second power amplifier transistor is grounded; the base of the fourth power amplifier transistor is connected to the second end of the third winding, the collector of the fourth power amplifier transistor outputs a fourth RF signal, and the emitter of the fourth power amplifier transistor is grounded.

[0096] See below Figure 6 and Figure 7 As shown, in at least one embodiment, the first transformer further includes a fifth winding S15, and the second transformer further includes a sixth winding S16, the fifth winding S15 and the sixth winding S16 are connected in series, the fifth winding S15 is coupled to the first winding S11 and the second winding S12, the sixth winding S16 is coupled to the third winding S13 and the fourth winding S14, and the second end of the fourth winding S14 is connected to the ground terminal through the fifth winding S15 and the sixth winding S16 connected in series. Due to the poor balance of the RF power amplifier, the fifth winding S15 and the sixth winding S16 are connected in this embodiment, and the fifth winding S15 is connected to the ground terminal. The first winding S11 is coupled with the second winding S12, the sixth winding S16 is coupled with the third winding S13 and the fourth winding S14. Since the fifth winding S15 and the sixth winding are connected close to the ground end, the second winding S12 and the fourth winding S14 are connected close to the signal output end. By coupling the first winding S11 with the fifth winding S15 close to the ground end and the second winding S12 close to the signal output end, and coupling the third winding S13 with the sixth winding S16 close to the ground end and the fourth winding S14 close to the signal output end, and making the first capacitor unit and the second winding in parallel, the balance of the RF power amplifier is further improved.

[0097] In a specific embodiment, refer to the following Figure 7 As shown, the second end of the fourth winding S14 is connected to the second end of the sixth winding S16, the first end of the sixth winding S16 is connected to the second end of the fifth winding S15, and the first end of the fifth winding S15 is grounded. Figure 6As shown, the second end of the fourth winding S14 is connected to the first end of the fifth winding S15, the second end of the fifth winding S15 is connected to the first end of the sixth winding S16, and the second end of the sixth winding S16 is grounded.

[0098] See below Figure 6 As shown, the second end of the fourth winding S14 is connected to the second end of the sixth winding S16, the first end of the sixth winding S16 is connected to the second end of the fifth winding S15, and the first end of the fifth winding S15 is grounded. In this embodiment, since the fifth winding S15 and the sixth winding are connected close to the ground end, and the second winding S12 and the fourth winding S14 are connected close to the signal output end, by coupling the first winding S11 with the fifth winding S15 close to the ground end and the second winding S12 close to the signal output end, and coupling the third winding S13 with the sixth winding S16 close to the ground end and the fourth winding S14 close to the signal output end, the impedance / phase imbalance between the first power amplifier circuit 10 and the second power amplifier circuit 20 can be improved, thereby reducing the overall loss of the RF power amplifier.

[0099] See below Figure 7 As shown, the second end of the fourth winding S14 is connected to the first end of the fifth winding S15, the second end of the fifth winding S15 is connected to the first end of the sixth winding S16, and the second end of the sixth winding S16 is grounded. In this embodiment, the sixth winding S16 is connected to the ground end, and the fifth winding S15 is connected to the fourth winding S14. Therefore, in this embodiment, since the fifth winding S15 and the sixth winding S16 are connected close to the ground end, and the second winding S12 and the fourth winding S14 are connected close to the signal output end, by coupling the first winding S11 with the fifth winding S15 close to the ground end and the second winding S12 close to the signal output end, and coupling the third winding S13 with the sixth winding S16 close to the ground end and the fourth winding S14 close to the signal output end, the impedance / phase imbalance between the first power amplifier circuit 10 and the second power amplifier circuit 20 can be improved, thereby reducing the overall loss of the RF power amplifier.

[0100] The present application also provides a radio frequency front-end module, referring to the following Figure 8As shown, it includes a substrate 300, and a first chip 100 and a second chip 200 arranged on the substrate 300, the first chip 100 includes a first power amplifier circuit and a second power amplifier circuit, the second chip 200 includes a first transformer, a second transformer and a first capacitor unit, the first transformer includes a first winding and a second winding, the second transformer includes a third winding and a fourth winding, the first power amplifier circuit is connected to a first pad of the first chip, the first pad is connected to a second pad of the second chip, the second pad is connected to the first winding, the second power amplifier circuit is connected to a third pad of the first chip, the third pad is connected to a fourth pad of the second chip, and the fourth pad is connected to the third winding; the first end of the second winding is connected to a signal output end, the second end of the second winding is connected to the first end of the fourth winding, and the second end of the fourth winding is connected to the ground end; wherein the first capacitor unit is connected in parallel with at least part of the coil of the second winding.

[0101] In at least one embodiment, the first pad may be connected to the second pad of the second chip by one or more jumpers or by wire bonding. Similarly, the third pad may be connected to the fourth pad of the second chip by one or more jumpers or by wire bonding.

[0102] In at least one embodiment, by integrating the first power amplifier circuit and the second power amplifier circuit in the first chip 100, and integrating the first transformer, the second transformer and the first capacitor unit in the second chip 200, the balance of the RF front-end module can be improved while improving the integration of the RF front-end module.

[0103] In at least one embodiment, the first chip may be a CMOS chip or an HBT chip, etc., and the second chip may be an IPD chip or an SOI chip, etc. This embodiment does not specifically limit the types of the first chip and the second chip.

[0104] In at least one embodiment, the first chip is a heterojunction bipolar transistor chip (HBT chip), that is, the transistor type included in the first power amplifier circuit and the second power amplifier circuit is an HBT transistor, and the second chip is an integrated product development chip (IPD chip), thereby improving the balance and integration of the RF front-end module while ensuring the overall performance of the RF front-end module.

[0105] This embodiment also provides a radio frequency front-end module, see below Fig. 9As shown, it includes a substrate 300, and a first chip 100, a first transformer 50, a second transformer 60 and a first capacitor unit 70 arranged on the substrate 300, the first chip includes a first power amplifier circuit and a second power amplifier circuit, the first transformer includes a first winding and a second winding, the second transformer includes a third winding and a fourth winding, the first power amplifier circuit is connected to a first pad of the first chip, the first pad is connected to a second pad of the substrate, the second pad is connected to the first winding, the second power amplifier circuit is connected to a third pad of the first chip, the third pad is connected to a fourth pad of the substrate, and the fourth pad is connected to the third winding; the first end of the second winding is connected to a signal output end, the second end of the second winding is connected to the first end of the fourth winding, and the second end of the fourth winding is connected to the ground end; wherein the first capacitor unit is connected in parallel with at least part of the coil of the second winding.

[0106] In at least one embodiment, the first pad may be connected to the second pad of the substrate by one or more jumpers or by wire bonding. Similarly, the third pad may be connected to the fourth pad of the substrate by one or more jumpers or by wire bonding.

[0107] In at least one embodiment, by integrating the first power amplifier circuit and the second power amplifier circuit in the first chip 10, and disposing the first transformer, the second transformer and the first capacitor unit on the substrate, the balance of the RF front-end module can be improved while improving the quality factor (Q value) of the RF front-end module. Since the first capacitor unit is disposed on the substrate, the capacitance value of the first capacitor unit can be set larger, and the adjustment range of the capacitance value of the first capacitor unit is wider.

[0108] In a specific embodiment, the first capacitor unit is a chip capacitor unit (SMD), which can improve the integration of the RF front-end module and facilitate the layout of various components in the RF front-end module.

[0109] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A radio frequency power amplifier, characterized in that: include A first power amplifier circuit, a second power amplifier circuit and a voltage synthesis network, wherein the voltage synthesis network includes a first transformer, a second transformer and a first capacitor unit, wherein the first transformer includes a first winding and a second winding, and the second transformer includes a third winding and a fourth winding; the first power amplifier circuit is connected to the first winding, the second power amplifier circuit is connected to the third winding, the first end of the second winding is connected to the signal transmission end, the second end of the second winding is connected to the first end of the fourth winding, and the second end of the fourth winding is connected to the ground end; wherein the first capacitor unit is connected in parallel with at least part of the coil of the second winding.

2. The radio frequency power amplifier according to claim 1, characterized in that: The output end of the first power amplifier circuit is connected to the first winding, the output end of the second power amplifier circuit is connected to the third winding, and the first capacitor unit is configured to balance the impedance between the output end of the first power amplifier circuit and the output end of the second power amplifier circuit; Alternatively, the input end of the first power amplifier circuit is connected to the first winding, the input end of the second power amplifier circuit is connected to the third winding, and the first capacitor unit is configured to balance the impedance between the input end of the first power amplifier circuit and the input end of the second power amplifier circuit.

3. The radio frequency power amplifier according to claim 1, characterized in that: The output end of the first power amplifier circuit is connected to the first winding, the output end of the second power amplifier circuit is connected to the third winding, and the first capacitor unit is configured to make the output end impedance of the first power amplifier circuit and the output end impedance of the second power amplifier circuit the same; Alternatively, the input end of the first power amplifier circuit is connected to the first winding, the input end of the second power amplifier circuit is connected to the third winding, and the first capacitor unit is configured to make the input end impedance of the first power amplifier circuit and the input end impedance of the second power amplifier circuit the same.

4. The radio frequency power amplifier according to claim 1, characterized in that: The first capacitor unit is configured to compensate for the capacitance value of the equivalent parasitic capacitance equivalently transformed by the second transformer at the first end of the fourth winding.

5. The radio frequency power amplifier according to claim 1, characterized in that: The capacitance value of the first capacitor unit ranges from (0*CP2 to 2*CP2), wherein CP2 is the capacitance value of the equivalent parasitic capacitance equivalently transformed by the second transformer at the first end of the fourth winding.

6. The radio frequency power amplifier according to claim 1, characterized in that: The capacitance value of the first capacitor unit ranges from (0 to 20 pF).

7. The radio frequency power amplifier according to claim 1, characterized in that: The first power amplifier circuit includes a first power amplifier transistor, and the second power amplifier circuit includes a second power amplifier transistor, the first power amplifier transistor is connected to the first end of the first winding, the second end of the first winding is connected to the ground terminal or the power supply terminal, the second power amplifier transistor is connected to the first end of the third winding, and the second end of the third winding is connected to the ground terminal or the power supply terminal.

8. The radio frequency power amplifier according to claim 7, characterized in that: The difference between the phase of the first RF signal at the first end of the first winding and the phase of the second RF signal at the first end of the third winding is in the range of [0°, 10°].

9. The radio frequency power amplifier according to claim 1, characterized in that: The first power amplifier circuit includes a first power amplifier transistor and a third power amplifier transistor, and the second power amplifier circuit includes a second power amplifier transistor and a fourth power amplifier transistor, the first power amplifier transistor is connected to the first end of the first winding, the third power amplifier transistor is connected to the second end of the first winding, the second power amplifier transistor is connected to the first end of the third winding, and the fourth power amplifier transistor is connected to the second end of the third winding.

10. The radio frequency power amplifier according to claim 9, characterized in that: The phase difference between the first RF signal at the first end of the first winding and the phase difference between the second RF signal at the first end of the third winding is in the range of [0°, 10°], and the phase difference between the third RF signal at the second end of the first winding and the fourth RF signal at the second end of the third winding is in the range of [0°, 10°].

11. The radio frequency power amplifier according to claim 1, characterized in that: The second winding includes a first coil segment and a second coil segment connected in series, the fourth winding includes a third coil segment and a fourth coil segment connected in series, the first end of the first coil segment is connected to the signal output end, the second end of the first coil segment is connected to the first end of the second coil segment, the second end of the second coil segment is connected to the first end of the third coil segment, the second end of the third coil segment is connected to the first end of the fourth coil segment, and the second end of the fourth coil segment is grounded; wherein the first capacitor unit is connected in parallel with the first coil segment.

12. The radio frequency power amplifier according to claim 9, characterized in that: The first power amplifying transistor, the third power amplifying transistor, the second power amplifying transistor and the fourth power amplifying transistor are all BJT transistors, including a base, a collector and an emitter; The base of the first power amplifier transistor receives an input first RF signal, the collector of the first power amplifier transistor is connected to the first end of the first winding, and the emitter of the first power amplifier transistor is grounded; the base of the third power amplifier transistor receives an input third RF signal, the collector of the third power amplifier transistor is connected to the second end of the first winding, and the emitter of the third power amplifier transistor is grounded; the base of the second power amplifier transistor receives an input second RF signal, the collector of the second power amplifier transistor is connected to the first end of the third winding, and the emitter of the second power amplifier transistor is grounded; the base of the fourth power amplifier transistor receives an input fourth RF signal, the collector of the fourth power amplifier transistor is connected to the second end of the third winding, and the emitter of the fourth power amplifier transistor is grounded; Alternatively, the base of the first power amplifier transistor is connected to the first end of the first winding, the collector of the first power amplifier transistor outputs a first radio frequency signal, and the emitter of the first power amplifier transistor is grounded; the base of the third power amplifier transistor is connected to the second end of the first winding, the collector of the third power amplifier transistor outputs a third radio frequency signal, and the emitter of the third power amplifier transistor is grounded; the base of the second power amplifier transistor is connected to the first end of the third winding, the collector of the second power amplifier transistor outputs a second radio frequency signal, and the emitter of the second power amplifier transistor is grounded; the base of the fourth power amplifier transistor is connected to the second end of the third winding, the collector of the fourth power amplifier transistor outputs a fourth radio frequency signal, and the emitter of the fourth power amplifier transistor is grounded.

13. The radio frequency power amplifier according to claim 1, characterized in that: The first transformer also includes a fifth winding, and the second transformer also includes a sixth winding, the fifth winding and the sixth winding are connected in series, the fifth winding is coupled to the first winding and the second winding, the sixth winding is coupled to the third winding and the fourth winding, and the second end of the fourth winding is connected to the ground terminal through the fifth winding and the sixth winding connected in series.

14. The radio frequency power amplifier according to claim 13, characterized in that: The second end of the fourth winding is connected to the second end of the sixth winding, the first end of the sixth winding is connected to the second end of the fifth winding, and the first end of the fifth winding is grounded; or, the second end of the fourth winding is connected to the first end of the fifth winding, the second end of the fifth winding is connected to the first end of the sixth winding, and the second end of the sixth winding is grounded.

15. A radio frequency front-end module, characterized in that: The RF front-end module includes a substrate, and a first chip and a second chip arranged on the substrate, the first chip includes a first power amplifier circuit and a second power amplifier circuit, the second chip includes a first transformer, a second transformer and a first capacitor unit, the first transformer includes a first winding and a second winding, the second transformer includes a third winding and a fourth winding, the first power amplifier circuit is connected to a first pad of the first chip, the first pad is connected to a second pad of the second chip, the second pad is connected to the first winding, the second power amplifier circuit is connected to a third pad of the first chip, the third pad is connected to a fourth pad of the second chip, and the fourth pad is connected to the third winding; the first end of the second winding is connected to a signal output end, the second end of the second winding is connected to the first end of the fourth winding, and the second end of the fourth winding is connected to a ground end; wherein the first capacitor unit is connected in parallel with at least part of the coil of the second winding.

16. The radio frequency front-end module according to claim 15, characterized in that: The first chip is a heterojunction bipolar transistor chip, and the second chip is an integrated product development chip.

17. A radio frequency front-end module, characterized in that: The RF front-end module includes a substrate, and a first chip, a first transformer, a second transformer and a first capacitor unit arranged on the substrate, the first chip includes a first power amplifier circuit and a second power amplifier circuit, the first transformer includes a first winding and a second winding, the second transformer includes a third winding and a fourth winding, the first power amplifier circuit is connected to a first pad of the first chip, the first pad is connected to a second pad of the substrate, the second pad is connected to the first winding, the second power amplifier circuit is connected to a third pad of the first chip, the third pad is connected to a fourth pad of the substrate, and the fourth pad is connected to the third winding; the first end of the second winding is connected to a signal output end, the second end of the second winding is connected to a first end of the fourth winding, and the second end of the fourth winding is connected to a ground end; wherein the first capacitor unit is connected in parallel with at least part of the coil of the second winding.

18. The radio frequency front-end module according to claim 17, characterized in that: The first capacitor unit is a chip capacitor unit.

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