A high-gain load-modulated balanced amplifier

Abstract

The present application relates to the technical field of radio frequency chip power amplifiers, and specifically to a high-gain load-modulated balanced amplifier, comprising: an RF input connected to the input end of a power divider, a first output end of the power divider connected to the input end of a phase shifter, a second output end of the power divider connected to the input end of an input coupler, an output end of the phase shifter connected to a control power amplifier, and an output end of the control power amplifier connected to an isolation end of the input coupler; a through-end of the input coupler connected to the input end of a first sub-balanced amplifier, a coupling end of the input coupler connected to the input end of a second sub-balanced amplifier, and an output end of the first sub-balanced amplifier connected to a coupling end of an output coupler; an output end of the second sub-balanced amplifier connected to a through-end of an output coupler; an isolation end of an output coupler connected to a reactance load, the other end of the reactance load being grounded; and an input end of the output coupler connected to an RF output, so that only a very low-power control signal is required to meet the requirements.

Description

Technical Field

[0001] The present application relates to the technical field of radio frequency chip power amplifiers, and in particular to a high-gain load-modulated balanced amplifier. Background Art

[0002] With the rapid development of wireless communication systems, the demand for high data rates and low system latency has increased significantly. Modern communication systems utilize complex modulation schemes in cellular and wireless local area networks, including 1024-QAM high-order quadrature amplitude modulation and orthogonal frequency division multiplexing, to maximize the use of spectrum resources. Modulation schemes have led to an increase in the peak-to-average power ratio of signals, which also places high demands on wireless communication systems. To cope with signals with high peak-to-average power ratios, power supply modulation and load modulation technologies are mainly used, such as Doherty power amplifier technology, dynamic load modulation technology based on varactor diodes, and the emerging load-modulated balanced amplifier (LMBA) technology.

[0003] Currently, both single-stage Doherty power amplifiers and single-stage load-modulated balanced amplifiers suffer from low gain, which places high demands on the driver power amplifier. Multi-stage load-modulated balanced amplifiers require six power cells, which results in an excessively large area and an extremely complex design. Furthermore, load-modulated balanced amplifiers require very high output power for the control signal. Especially as the power backoff increases, the required output power of the control signal approaches that of the balanced amplifier, necessitating a very large power cell to provide sufficient output power. Summary of the Invention

[0004] This application aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] Therefore, the purpose of this application is to provide a high-gain load-modulated balanced amplifier.

[0006] In order to achieve the above objectives, the technical solution of the present application provides a high-gain load-modulated balanced amplifier, comprising: a power divider, a phase shifter, a control power amplifier, and a balanced amplifier; the balanced amplifier comprises an input coupler, an output coupler, a first sub-balanced amplifier, and a second sub-balanced amplifier;

[0007] Among them, the RF input is connected to the input end of the power divider, the first output end of the power divider is connected to the input end of the phase shifter, the second output end of the power divider is connected to the input end of the input coupler, the output end of the phase shifter is connected to the control power amplifier, and the output end of the control power amplifier is connected to the isolation end of the input coupler; the through end of the input coupler is connected to the input end of the first sub-balanced amplifier, the coupling end of the input coupler is connected to the input end of the second sub-balanced amplifier, and the output end of the first sub-balanced amplifier is connected to the coupling end of the output coupler; the output end of the second sub-balanced amplifier is connected to the through end of the output coupler; the isolation end of the output coupler is connected to the inductive load, and the other end of the inductive load is grounded; the input end of the output coupler is connected to the RF output.

[0008] Furthermore, the control power amplifier includes a first input matching network, a control power amplifier power unit and a first class J output matching network, wherein the output end of the phase shifter is connected to the first input matching network, the output end of the first input matching network is connected to the input end of the control power amplifier power unit, the output end of the control power amplifier power unit is connected to the first class J output matching network, and the output end of the class J output matching network is connected to the isolation end of the input coupler.

[0009] Furthermore, the first sub-balanced amplifier and the second sub-balanced amplifier adopt the same structure, including a second input matching network, a driving stage power unit, an inter-stage matching network, a power stage power unit and a second Class J output matching network, wherein the output end of the input matching network is connected to the input end of the driving stage power unit, the output end of the driving stage power unit is connected to the inter-stage matching network, the output end of the inter-stage matching network is connected to the power stage power unit, the output end of the power stage power unit is connected to the Class J output matching network, and the output end of the Class J output matching network is connected to the coupling end of the output coupler.

[0010] Furthermore, the control power amplifier, the driving stage power unit and the output stage power unit are all composed of a plurality of transistors connected in parallel.

[0011] Furthermore, the driving stage power unit and the output stage power unit are in the class AB working mode, and the control power amplifier is in the class C working mode.

[0012] Furthermore, the input coupler includes: a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first inductor, a second inductor, a third inductor, and a fourth inductor, wherein the first end of the first capacitor is a coupling end, the second end of the first capacitor is an input end, the first end of the first capacitor is connected to the first end of the first inductor, the second end of the first inductor is connected to the first end of the third capacitor, the first end of the fourth capacitor, and the first end of the third inductor, the second end of the third capacitor is grounded, the second end of the fourth capacitor is connected to the first end of the fifth capacitor, the first end of the second inductor, and the first end of the fourth inductor, the second end of the second inductor is connected to the second end of the first capacitor, and the second end of the fifth capacitor is grounded; the second end of the fourth inductor is connected to the first end of the second capacitor and serves as a through-end, and the second end of the second capacitor is connected to the second end of the third inductor and serves as an isolation end;

[0013] The first capacitor and the second capacitor have the same value, and the third capacitor, the fourth capacitor and the fifth capacitor have the same value. The first inductor, the second inductor, the third inductor and the fourth inductor have the same value. The first inductor and the second inductor are coupled with each other and there is a coupling factor k. The third inductor and the fourth inductor have a coupling factor k.

[0014] Furthermore, the output coupler includes: a sixth capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, a fifth inductor, a sixth inductor, a seventh inductor, and an eighth inductor, wherein the first end of the sixth capacitor is connected to the first end of the fifth inductor and serves as an isolation end, the second end of the sixth capacitor is connected to the first end of the sixth inductor and serves as a pass-through end, the second end of the fifth inductor is connected to the first end of the seventh capacitor, the first end of the eighth capacitor, and the first end of the seventh inductor; the second end of the sixth inductor is connected to the second end of the eighth capacitor, the first end of the ninth capacitor, and the first end of the eighth inductor; the second end of the seventh inductor is connected to the first end of the tenth capacitor and serves as a coupling end; the second end of the eighth inductor is connected to the second end of the tenth capacitor and serves as an input end, and the second end of the seventh capacitor and the second end of the ninth capacitor are grounded;

[0015] The sixth capacitor and the tenth capacitor of the output coupler have equal values, the seventh capacitor, the eighth capacitor and the ninth capacitor have equal values, the fifth inductor, the sixth inductor, the seventh inductor and the eighth inductor have equal inductance values, the fifth inductor and the sixth inductor are coupled with each other, and there is a coupling factor k, and the seventh inductor and the eighth inductor are coupled with each other, and there is a coupling factor k.

[0016] The advantage of the high-gain load-modulated balanced amplifier of the present application is that, by connecting the control amplifier to the isolated port of the input coupler, the power of the control amplifier is amplified along with the balanced amplifier. By connecting a reactive load to the isolated port of the output coupler, the control signal of the control amplifier is reflected back to the balanced amplifier, thereby modulating the load impedance of the balanced amplifier. This has the advantage that only a very low-power control signal is required to meet the requirements. In addition, to further improve the gain of the power amplifier, the balanced amplifier adopts a two-stage cascade design. For traditional single-input LMBAs, the control amplifier is terminated at the isolated port of the output coupler. The balanced amplifier and the control amplifier require similar gains to ensure that the power required for load modulation can be obtained. Therefore, both the balanced amplifier and the control amplifier need to adopt a two-stage cascade design. Another advantage of the present application is that the control amplifier is short-circuited to the isolated port of the input coupler, and the output power of the control amplifier is amplified along with the balanced amplifier. Therefore, the control amplifier only needs to use a single power unit, without the need to increase its gain, thus effectively reducing the complexity of the system.

[0017] Additional aspects and advantages of the present application will become apparent from the following description or may be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The following is a structural block diagram of a high-gain load-modulated balanced amplifier provided in an embodiment of the present application;

[0019] Figure 2 A circuit diagram showing the control function provided by an embodiment of the present application is shown;

[0020] Figure 3 shows a circuit schematic diagram of an input coupler provided in an embodiment of the present application;

[0021] Figure 4 A circuit schematic diagram of a sub-balanced amplifier provided in an embodiment of the present application is shown;

[0022] Figure 5 shows a circuit schematic diagram of an output coupler provided in an embodiment of the present application;

[0023] Figure 6 A circuit schematic diagram of a class J output matching network provided in an embodiment of the present application is shown;

[0024] Figure 7 The schematic diagram of the circuit of the power divider provided in the embodiment of the present application is shown;

[0025] Figure 8 The current and voltage waveforms of a high-gain load-modulated balanced amplifier provided by an embodiment of the present application are shown. DETAILED DESCRIPTION

[0026] In order to more clearly understand the above-mentioned objectives, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features therein can be combined with each other in the absence of conflict.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0028] Figure 1 The block diagram of a high-gain load-modulated balanced amplifier of the present application is shown. It includes: a power splitter, a phase shifter, a control power amplifier, and a balanced amplifier; the balanced amplifier includes an input coupler, an output coupler, a first sub-balanced amplifier, and a second sub-balanced amplifier;

[0029] The RF input is connected to the input of the power splitter, the first output of the power splitter is connected to the input of the phase shifter, the second output of the power splitter is connected to the input of the input coupler, the output of the phase shifter is connected to the control power amplifier, and the output of the control power amplifier is connected to the isolation terminal of the input coupler. The through-port of the input coupler is connected to the input of the first sub-balanced amplifier, the coupled port of the input coupler is connected to the input of the second sub-balanced amplifier, the output of the first sub-balanced amplifier is connected to the coupled port of the output coupler; the output of the second sub-balanced amplifier is connected to the through-port of the output coupler; the isolated port of the output coupler is connected to a reactance load, the other end of which is grounded. The input of the output coupler is connected to the RF output.

[0030] A power splitter is a device that splits the energy of one input signal into two equal or unequal energy paths, and can also combine the energy of multiple signals into one output.

[0031] A phase shifter is a device that changes the phase of a signal. Its main function is to introduce a controllable phase delay. Phase shifters can be passive devices, such as microstrip lines and transmission lines, or active devices, such as semiconductor-based phase shifters.

[0032] Couplers consist of an input coupler at the input and an output coupler at the output. Their operating principle is based on the coupling effect of electromagnetic fields. When a signal propagates along the primary transmission path, some of the energy is transferred into the coupled path through the coupling structure. Coupler design goals are to achieve a specific degree of coupling and directivity while minimizing insertion loss and reflections.

[0033] In this embodiment, the control amplifier is connected to the isolated port of the input coupler, amplifying the power of the control amplifier along with the balanced amplifier. By connecting a reactive load to the isolated port of the output coupler, the control signal of the control amplifier is reflected back to the balanced amplifier, modulating the load impedance of the balanced amplifier. This has the advantage of requiring only a very low-power control signal to meet the requirements. A control amplifier refers to a control amplifier.

[0034] In one embodiment, see Figure 2 As shown, the control amplifier includes a first input matching network, a control amplifier power unit, and a first class J output matching network. The first input matching network is at the input end and is used to match the input impedance of the circuit with the output impedance. L-type matching networks, π-type matching networks, and T-type matching networks can be used, without limitation. The control amplifier power unit adopts a transistor structure, with the base of the transistor connected to the first input matching network, the collector of the transistor connected to the output of the first class J output matching network, the emitter of the transistor grounded, and the base of the transistor connected to a bias voltage via a resistor.

[0035] In one embodiment, see Figure 4 As shown, the first sub-balanced amplifier and the second sub-balanced amplifier adopt the same structure, including a second input matching network, a driver stage power unit, an inter-stage matching network, a power stage power unit, and a second Class-J output matching network. Taking the first sub-balanced amplifier as an example: the through-end of the input coupler is connected to the second input matching network of the first sub-balanced amplifier, the output end of the second input matching network of the first sub-balanced amplifier is connected to the input end of the driver stage power unit of the first sub-balanced amplifier, the output end of the driver stage power unit of the first sub-balanced amplifier is connected to the inter-stage matching network of the first sub-balanced amplifier, the output end of the inter-stage matching network of the first sub-balanced amplifier is connected to the power stage power unit of the first sub-balanced amplifier, and the output end of the power stage power unit of the first sub-balanced amplifier is connected to the second Class-J output matching network of the first sub-balanced amplifier; and the output end of the second Class-J output matching network of the first sub-balanced amplifier is connected to the coupling end of the output coupler.

[0036] Similarly: the coupling end of the input coupler is connected to the second input matching network of the second sub-balanced amplifier, the output end of the second input matching network of the second sub-balanced amplifier is connected to the input end of the driver stage power unit of the second sub-balanced amplifier, the output end of the driver stage power unit of the second sub-balanced amplifier is connected to the inter-stage matching network of the second sub-balanced amplifier, the output end of the inter-stage matching network of the second sub-balanced amplifier is connected to the power stage power unit of the second sub-balanced amplifier, the output end of the power stage power unit of the second sub-balanced amplifier is connected to the second Class-J output matching network of the second sub-balanced amplifier; and the output end of the second Class-J output matching network of the second sub-balanced amplifier is connected to the through end of the output coupler.

[0037] The driver power unit adopts a multi-stage transistor structure. The base of each stage transistor is connected to the bias voltage through a resistor. The base of the first stage transistor is connected to the output of the second input matching network. The collector of the first stage transistor is connected to the base of the next stage transistor. The emitter of the first stage transistor is grounded, and so on. The transistor of the last stage is output to the inter-stage matching network through the collector.

[0038] The power stage power unit also adopts a multi-stage transistor structure. The base of the transistor in each stage is connected to the bias voltage through a resistor. The base of the transistor in the first stage is connected to the output of the inter-stage matching network. The collector of the transistor in the first stage is connected to the base of the transistor in the next stage. The emitter of the transistor in the first stage is grounded, and so on. The transistor in the last stage is output to the second class J output matching network through the collector.

[0039] The driver-stage power unit of the first sub-balanced amplifier, the output-stage power unit of the first sub-balanced amplifier, the driver-stage power unit of the second sub-balanced amplifier, and the output-stage power unit of the second sub-balanced amplifier operate in Class AB mode, while the control amplifier operates in Class C mode. The control amplifier is activated at the power backoff point. By connecting the control amplifier to the isolated port of the input coupler, the power of the control amplifier is amplified along with the balanced amplifier. By connecting a reactive load to the isolated port of the output coupler, the control signal of the control amplifier is reflected back to the balanced amplifier, modulating the load impedance of the balanced amplifier. This approach has the advantage of requiring only a very low-power control signal to meet the requirements.

[0040] In order to further improve the gain of the power amplifier, the first sub-balanced amplifier and the second sub-balanced amplifier adopt a two-stage cascade design. For traditional single-input LMBAs, the control power amplifier is connected to the isolated port of the output coupler, and the balanced amplifier and the control power amplifier require similar gains to ensure that the power required for load modulation behavior can be obtained. Therefore, both the balanced amplifier and the control power amplifier need to adopt a two-stage cascade design. Another advantage of the present application is that the control power amplifier is short-circuited to the isolated port of the input coupler, and the output power of the control power amplifier is amplified together with the balanced amplifier. Therefore, the control power amplifier only needs to use one power unit, and no additional power unit is required to increase the gain, thereby effectively reducing the complexity of the system.

[0041] In one embodiment, participating Figure 3 As shown, the input coupler includes: a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first inductor, a second inductor, a third inductor and a fourth inductor, wherein the first end of the first capacitor is a coupling end, the second end of the first capacitor is an input end, the first end of the first capacitor is connected to the first end of the first inductor, the second end of the first inductor is connected to the first end of the third capacitor, the first end of the fourth capacitor and the first end of the third inductor, the second end of the third capacitor is grounded, the second end of the fourth capacitor is connected to the first end of the fifth capacitor, the first end of the second inductor and the first end of the fourth inductor, the second end of the second inductor is connected to the second end of the first capacitor, and the second end of the fifth capacitor is grounded; the second end of the fourth inductor is connected to the first end of the second capacitor and serves as a through end, the second end of the second capacitor is connected to the second end of the third inductor and serves as an isolation end.

[0042] The first and second capacitors have the same value, the third to fifth capacitors have the same value, the first to fourth inductors have the same value, the first and second inductors are coupled to each other with a coupling factor k, and the third and fourth inductors have a coupling factor k.

[0043] See also Figure 5 As shown, the structure of the output coupler is the same as that of the input coupler, including: a sixth capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, a fifth inductor, a sixth inductor, a seventh inductor and an eighth inductor, wherein the first end of the sixth capacitor is connected to the first end of the fifth inductor and serves as an isolation end, the second end of the sixth capacitor is connected to the first end of the sixth inductor and serves as a through end, the second end of the fifth inductor is connected to the first end of the seventh capacitor, the first end of the eighth capacitor and the first end of the seventh inductor; the second end of the sixth inductor is connected to the second end of the eighth capacitor, the first end of the ninth capacitor and the first end of the eighth inductor; the second end of the seventh inductor is connected to the first end of the tenth capacitor and serves as a coupling end; the second end of the eighth inductor is connected to the second end of the tenth capacitor and serves as an input end, and the second end of the seventh capacitor and the second end of the ninth capacitor are grounded.

[0044] The sixth and tenth capacitors of the output coupler have equal values, and the seventh through ninth capacitors have equal values. The fifth through eighth inductors have equal inductances. The fifth and sixth inductors are mutually coupled, with a coupling factor k. The seventh and eighth inductors are mutually coupled, with a coupling factor k.

[0045] In order to further improve the efficiency of a high-gain load-modulated balanced amplifier, a class J output matching network is used. Figure 6 The circuit includes a ninth inductor, an eleventh capacitor, a twelfth capacitor, a tenth inductor, a thirteenth capacitor, an eleventh inductor, and a fourteenth capacitor, wherein the first end of the ninth inductor and the first end of the eleventh capacitor are both connected to the input end, the second end of the ninth inductor and the second end of the eleventh capacitor are grounded, the input end is connected to the first end of the eleventh capacitor and the first end of the tenth capacitor, the second end of the eleventh capacitor is connected to the second end of the tenth capacitor, and is connected to the first end of the eleventh inductor and the first end of the thirteenth capacitor, the second end of the thirteenth capacitor is grounded, the second end of the eleventh inductor is connected to the first end of the fourteenth capacitor, and the second end of the fourteenth capacitor serves as the output end.

[0046] In one embodiment, see Figure 7 As shown, the power divider includes an input terminal, a first output terminal and a second output terminal, wherein the output terminal is grounded through a fifteenth capacitor and connected to the first end of the twelfth inductor and the first end of the thirteenth inductor, the second end of the twelfth inductor and the second end of the thirteenth inductor serve as the first output terminal and the second output terminal respectively, a sixteenth capacitor and a first resistor connected in series are connected between the first output terminal and the second output terminal, one end of the fourteenth inductor is connected between the sixteenth capacitor and the first resistor, and the other end of the fourteenth inductor is grounded.

[0047] Class J technology is based on waveform engineering to improve efficiency. In terms of fundamental waveform shaping, it reduces the overlapping angle of fundamental voltage and current, thereby reducing the heat loss of transistors caused by waveform overlap, and improving power amplifier efficiency from the perspective of reducing transistor power dissipation. In terms of second harmonic waveform shaping, the second harmonic is made into a pure imaginary number, which does not consume energy, reduces harmonic energy consumption, and thus increases the proportion of fundamental energy, thereby improving efficiency from the perspective of increasing the fundamental output power of the transistor. The output current and voltage waveforms of the balanced amplifier using the Class J output matching network are as follows: Figure 8 As shown, the dotted line corresponds to the current waveform, and the corresponding voltage waveform is realized. There is a 45° phase shift in the current and voltage waveforms. In addition, the voltage waveform is close to 0 within half a cycle, and there is little overlap between the voltage and current waveforms, which effectively improves the efficiency of the power amplifier.

[0048] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A high-gain load-modulated balanced amplifier, characterized in that: include: A power divider, a phase shifter, a control power amplifier and a balanced amplifier; the balanced amplifier includes an input coupler, an output coupler, a first sub-balanced amplifier and a second sub-balanced amplifier; Among them, the RF input is connected to the input end of the power divider, the first output end of the power divider is connected to the input end of the phase shifter, the second output end of the power divider is connected to the input end of the input coupler, the output end of the phase shifter is connected to the control power amplifier, and the output end of the control power amplifier is connected to the isolation end of the input coupler; the through end of the input coupler is connected to the input end of the first sub-balanced amplifier, the coupling end of the input coupler is connected to the input end of the second sub-balanced amplifier, and the output end of the first sub-balanced amplifier is connected to the coupling end of the output coupler; the output end of the second sub-balanced amplifier is connected to the through end of the output coupler; the isolation end of the output coupler is connected to the inductive load, and the other end of the inductive load is grounded; the input end of the output coupler is connected to the RF output.

2. The high-gain load-modulated balanced amplifier according to claim 1, wherein: The control power amplifier includes a first input matching network, a control power amplifier power unit and a first class J output matching network, wherein the output end of the phase shifter is connected to the first input matching network, the output end of the first input matching network is connected to the input end of the control power amplifier power unit, the output end of the control power amplifier power unit is connected to the first class J output matching network, and the output end of the class J output matching network is connected to the isolation end of the input coupler.

3. The high-gain load-modulated balanced amplifier according to claim 1, wherein: The first sub-balanced amplifier and the second sub-balanced amplifier adopt the same structure, including a second input matching network, a driving stage power unit, an inter-stage matching network, a power stage power unit and a second Class J output matching network, wherein the output end of the input matching network is connected to the input end of the driving stage power unit, the output end of the driving stage power unit is connected to the inter-stage matching network, the output end of the inter-stage matching network is connected to the power stage power unit, the output end of the power stage power unit is connected to the Class J output matching network, and the output end of the Class J output matching network is connected to the coupling end of the output coupler.

4. The high-gain load-modulated balanced amplifier according to claim 3, wherein: The control power amplifier, the driving stage power unit and the output stage power unit are all composed of multiple transistors connected in parallel.

5. The high-gain load-modulated balanced amplifier according to claim 4, characterized in that: The driving stage power unit and the output stage power unit are in the class AB working mode, and the control power amplifier is in the class C working mode.

6. The high-gain load-modulated balanced amplifier according to claim 1, characterized in that: The input coupler includes: a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first inductor, a second inductor, a third inductor, and a fourth inductor, wherein the first end of the first capacitor is a coupling end, the second end of the first capacitor is an input end, the first end of the first capacitor is connected to the first end of the first inductor, the second end of the first inductor is connected to the first end of the third capacitor, the first end of the fourth capacitor, and the first end of the third inductor, the second end of the third capacitor is grounded, the second end of the fourth capacitor is connected to the first end of the fifth capacitor, the first end of the second inductor, and the first end of the fourth inductor, the second end of the second inductor is connected to the second end of the first capacitor, and the second end of the fifth capacitor is grounded; the second end of the fourth inductor is connected to the first end of the second capacitor and serves as a through-end, and the second end of the second capacitor is connected to the second end of the third inductor and serves as an isolation end; The first capacitor and the second capacitor have the same value, and the third capacitor, the fourth capacitor and the fifth capacitor have the same value. The first inductor, the second inductor, the third inductor and the fourth inductor have the same value. The first inductor and the second inductor are coupled with each other and there is a coupling factor k. The third inductor and the fourth inductor have a coupling factor k.

7. The high-gain load-modulated balanced amplifier according to claim 1, characterized in that: The output coupler includes: a sixth capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, a fifth inductor, a sixth inductor, a seventh inductor, and an eighth inductor, wherein a first end of the sixth capacitor is connected to a first end of the fifth inductor and serves as an isolation end, a second end of the sixth capacitor is connected to a first end of the sixth inductor and serves as a through end, a second end of the fifth inductor is connected to a first end of the seventh capacitor, a first end of the eighth capacitor, and a first end of the seventh inductor; a second end of the sixth inductor is connected to a second end of the eighth capacitor, a first end of the ninth capacitor, and a first end of the eighth inductor; a second end of the seventh inductor is connected to a first end of the tenth capacitor and serves as a coupling end; a second end of the eighth inductor is connected to a second end of the tenth capacitor and serves as an input end, and a second end of the seventh capacitor and a second end of the ninth capacitor are grounded; The sixth capacitor and the tenth capacitor of the output coupler have equal values, the seventh capacitor, the eighth capacitor and the ninth capacitor have equal values, the fifth inductor, the sixth inductor, the seventh inductor and the eighth inductor have equal inductance values, the fifth inductor and the sixth inductor are coupled with each other, and there is a coupling factor k, and the seventh inductor and the eighth inductor are coupled with each other, and there is a coupling factor k.

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