Asymmetric reflective analog pre-distortion linearizer with multiple adjustments

Abstract

The utility model relates to the technical field of microwave circuits, in particular to an asymmetric reflective analog pre-distortion linearizer with various adjustments. The analog predistortion linearizer comprises a coupler, a nonlinear branch and a variable load branch, and the coupler is used for separating an input signal into a first branch signal and a second branch signal; the nonlinear branch is used for adjusting the first branch signal to obtain a nonlinear signal with an adjustable amplitude curve, and the nonlinear signal is a third branch signal; the variable load circuit is used for adjusting the second branch signal to obtain a phase-adjustable fourth branch signal; and the coupler is also used for synthesizing the third branch signal and the fourth branch signal to obtain a linearized output signal. The amplitude curve shape is adjustable and the compensation amount is not changed by adjusting the bias voltage of the nonlinear impedance matching network, and the phase compensation is independently adjustable by adjusting the bias voltage of the variable load circuit.

Description

Technical Field

[0001] The utility model relates to the technical field of microwave circuits, in particular to an asymmetric reflection type analog predistortion linearizer with multiple adjustabilities. Background Art

[0002] At present, wireless communication technology represented by mobile communication is developing rapidly. As an indispensable key component of the communication system, the nonlinear distortion generated by the power amplifier under high output power has an adverse effect on the overall signal transmission. Therefore, the power amplifier must have a large linear dynamic range. Linearization technology can effectively improve the linearity of the power amplifier and reduce its nonlinear distortion, which has important practical value in wireless communication systems. Among them, analog predistortion (APD) linearization technology is widely used to improve the linear performance of power amplifiers due to its simple structure and low cost. The key to APD linearization technology is to compensate for distortion by generating reverse gain nonlinearity and phase nonlinearity. The use of a predistortion linearizer can not only improve the nonlinear distortion of the power amplifier, but also make the power amplifier work closer to saturation, thereby improving efficiency performance.

[0003] The analog predistortion linearizer with a symmetrical reflective structure in the prior art can achieve good isolation between the input signal and the output signal and has good matching characteristics, so it is widely used in APD. Although its circuit structure is simple, the compensation of amplitude and phase will affect each other during adjustment, making it difficult for amplitude compensation and phase compensation to simultaneously meet the linearization requirements of the power amplifier (PA). At the same time, most linearizers currently only focus on the adjustment of the amplitude and phase compensation, while there is little research on the adjustment of the amplitude and phase curve shape, so that the compensation accuracy of the linearization result cannot meet the linearization requirements of the PA. Summary of the invention

[0004] Aiming at the problems in the existing analog predistortion linearization technology that amplitude compensation and phase compensation influence each other and the compensation accuracy of the linearization result cannot meet the linearization requirements of the power amplifier, the utility model provides an asymmetric reflective analog predistortion linearizer with multiple adjustabilities, which can realize independent adjustment of phase compensation and adjustment of the shape of the amplitude compensation curve, thereby meeting the linearization requirements of the power amplifier.

[0005] The utility model provides an asymmetric reflective analog predistortion linearizer with multiple adjustabilities, comprising a coupler, a nonlinear branch and a variable load circuit;

[0006] The coupler is used to separate the input signal into a first branch signal and a second branch signal;

[0007] The nonlinear branch is used to adjust the shape of the amplitude compensation curve of the first branch signal to obtain a third branch signal;

[0008] The variable load circuit is used to adjust the phase compensation of the second branch signal to obtain a fourth branch signal;

[0009] The coupler is also used to synthesize the third branch signal and the fourth branch signal to obtain a linearized output signal.

[0010] Furthermore, the nonlinear branch includes a nonlinear impedance matching network and a nonlinear load circuit connected in series; the nonlinear impedance matching network is used to provide a nonlinearly varying impedance network to adjust the first branch signal to obtain a first nonlinear signal; the nonlinear load circuit is used to provide a nonlinear load to adjust the first nonlinear signal to obtain a third branch signal.

[0011] Furthermore, the coupler comprises four ports, the port (1) of the coupler is used to receive an input signal, the port (2) of the coupler is connected to the input end of the nonlinear impedance matching network, the port (3) of the coupler is connected to the input end of the variable load circuit, and the port (4) of the coupler is used to output a linearized output signal.

[0012] Furthermore, the nonlinear impedance matching network includes a first bias circuit, a first Schottky diode, a first microstrip line and a DC blocking capacitor; the common connection end of the first bias circuit and the first microstrip line is connected to the positive electrode of the first Schottky diode, the negative electrode of the first Schottky diode is grounded, and the other end of the first microstrip line is connected to the nonlinear load circuit through the DC blocking capacitor; wherein the common connection end of the first bias circuit and the first microstrip line serves as the input end of the first branch signal; and the first bias circuit is used to generate a first bias voltage for the first Schottky diode.

[0013] Furthermore, the first bias circuit includes a first RF choke inductor, a first resistor and a first voltage source; one end of the first RF choke inductor serves as a common connection end with the first microstrip line, and the other end is connected to the first voltage source through the first resistor.

[0014] Furthermore, the nonlinear load circuit includes a second bias circuit, a second Schottky diode, a second microstrip line and a second resistor; the common connection end of the second bias circuit and the second microstrip line is connected to the positive electrode of the second Schottky diode, the negative electrode of the second Schottky diode is grounded, and the other end of the second microstrip line is grounded through the second resistor; wherein the common connection end of the second bias circuit and the second microstrip line is connected to the output end of the nonlinear impedance matching network; the second bias circuit is used to generate a second bias voltage for the second Schottky diode.

[0015] Furthermore, the second bias circuit includes a second RF choke inductor, a third resistor and a second voltage source; one end of the second RF choke inductor serves as a common connection end with the second microstrip line, and the other end is connected to the second voltage source through the third resistor.

[0016] Further, the variable load circuit includes a third bias circuit, a third microstrip line, a fourth microstrip line, a fifth microstrip line, a first varactor diode and a second varactor diode; the common connection end of the third microstrip line and the third bias circuit is connected to the fourth microstrip line, the other end of the third microstrip line is connected to the cathode of the first varactor diode, and the anode of the first varactor diode is grounded; the other end of the fourth microstrip line is connected to the cathode of the second varactor diode through the fifth microstrip line, and the anode of the second varactor diode is grounded; wherein the common connection end of the third microstrip line and the third bias circuit serves as the input end of the second branch signal; the third bias circuit is used to generate a third bias voltage for the first varactor diode and the second varactor diode.

[0017] Furthermore, the third bias circuit includes a third radio frequency choke inductor and a third voltage source; one end of the third radio frequency choke inductor serves as a common connection end with the third microstrip line, and the other end is connected to the third voltage source.

[0018] Compared with the prior art, the utility model has the following technical effects:

[0019] The utility model changes the two symmetrical branches of the existing reflective analog predistortion linearizer into two asymmetrical branches such as a nonlinear branch and a variable load circuit. By adjusting the bias voltage of the variable load circuit, the linearizer can have the characteristic of independently adjustable phase compensation. The asymmetric reflective analog predistortion linearizer proposed by the utility model has the function of independently adjusting the phase. When adjusting the phase compression amount, the amplitude fluctuation is very small and almost unchanged, thereby expanding the adjustment flexibility of the linearizer. Compared with the existing reflective analog predistortion linearizer, the utility model can achieve a more accurate compensation effect.

[0020] The utility model can achieve constant amplitude compensation and adjustable shape by adjusting the bias voltage of the nonlinear impedance matching network in the nonlinear branch. The adjustable shape here means that the shape of the compensation curve can be adjusted when the amplitude and phase compensation of the predistorter remains unchanged, so as to achieve accurate fitting of the nonlinear distortion characteristics of the power amplifier.

[0021] The asymmetric reflective analog predistortion linearizer with multiple adjustabilities provided by the utility model has a simple structure, is easy to implement, and can be widely applied to multiple power amplifiers. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1One of the structural schematic diagrams of an asymmetric reflective analog predistortion linearizer with multiple adjustabilities provided by an embodiment of the utility model;

[0023] Figure 2 A second structural schematic diagram of an asymmetric reflective analog predistortion linearizer with multiple adjustabilities provided by an embodiment of the utility model;

[0024] Figure 3 A schematic diagram of a nonlinear branch structure provided by an embodiment of the utility model;

[0025] Figure 4 A schematic diagram of a variable load circuit structure provided by an embodiment of the utility model;

[0026] Figure 5 The nonlinear branch impedance variation curve provided by the embodiment of the utility model;

[0027] Figure 6 A gain variation curve diagram of a nonlinear branch under different bias voltages provided by an embodiment of the utility model;

[0028] Figure 7 Phase variation curve diagram of the nonlinear branch under different bias voltages provided by the embodiment of the utility model;

[0029] Figure 8 The equal gain compensation amount curve diagram and the equal phase compensation amount curve diagram of the asymmetric analog predistorter provided by the embodiment of the utility model at the center frequency (11.7GHz);

[0030] Fig. 9 A gain variation curve diagram of a variable load circuit under different bias voltages provided by an embodiment of the utility model;

[0031] Fig.10 The phase change curve diagram of the variable load circuit under different bias voltages provided by the embodiment of the utility model. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model will be further described in detail below in conjunction with the drawings in the embodiments of the utility model. It should be understood that the specific embodiments described here are only used to solve the utility model and are not used to limit the utility model.

[0033] Combination Figure 1 and Figure 2As shown, an embodiment of the utility model provides an asymmetric reflective analog predistortion linearizer with multiple adjustabilities, including a coupler, a nonlinear branch and a variable load circuit. The coupler is used to separate the input signal into a first branch signal and a second branch signal. The nonlinear branch is used to adjust the shape of the amplitude compensation curve of the first branch signal to obtain a third branch signal. The variable load circuit is used to adjust the phase compensation of the second branch signal to obtain a fourth branch signal. The coupler is also used to synthesize the third branch signal and the fourth branch signal to obtain a linearized output signal.

[0034] It can be understood that the above coupler is a conventional signal processing device in the art, which can realize signal separation and synthesis. The specific type and model can be selected according to the actual application scenario. In this embodiment, a 3dB coupler is used. The nonlinear branch is a circuit in the art that provides a function of adjusting the shape of the amplitude compensation curve of the signal, so that the input first branch signal produces nonlinearity. The variable load circuit is a circuit in the art that provides a function of adjusting the phase compensation of the signal to generate a linear signal.

[0035] Specifically, the nonlinear branch generates nonlinearity for the first branch signal, and its impedance can be adjusted as required, so that the overall signal of the nonlinear branch has amplitude phase distortion characteristics. The variable load circuit generates different linear signals for the input signal, so that the amplitude compensation of the synthesized signal remains unchanged and the phase compensation is variable. The coupler then synthesizes the signals of the nonlinear branch and the variable load circuit to obtain a linearized output signal.

[0036] like Figure 2 As shown, in one embodiment, the nonlinear branch includes a nonlinear impedance matching network and a nonlinear load circuit. The nonlinear impedance matching network is used to provide a nonlinearly changing impedance network to adjust the first branch signal to obtain a first nonlinear signal. The nonlinear load circuit is used to provide a nonlinear load to adjust the first nonlinear signal to obtain a third branch signal.

[0037] It can be understood that the nonlinear impedance matching network is a circuit that provides an impedance network in the art, which is used to generate a weak nonlinear characteristic, and this nonlinear characteristic can make the shape of the amplitude compensation curve of the signal adjustable and the compensation amount unchanged. The nonlinear load circuit is a nonlinear element or circuit in the art, which is used to generate a nonlinear characteristic, and this nonlinear characteristic changes with the input power. The nonlinear impedance matching network and the nonlinear load circuit are used to provide an impedance network and a nonlinear load for the input first branch signal so that it has the required amplitude phase distortion characteristics.

[0038] like Figure 2As shown, in one embodiment, the coupler includes four ports, port 1 of the coupler is used to receive an input signal, port 2 of the coupler is connected to the input end of the nonlinear impedance matching network, port 3 of the coupler is connected to the input end of the variable load circuit, and port 4 of the coupler is used to output a linearized output signal.

[0039] Specifically, the signal enters from port 1 of the coupler and is divided into a first branch signal and a second branch signal by the coupler. The first branch signal enters the nonlinear branch from port 2 of the coupler, and the second branch signal enters the variable load circuit from port 3 of the coupler. When the first branch signal enters the nonlinear branch, it first passes through a nonlinear impedance matching network with a low bias voltage. At this time, the signal only obtains a weak nonlinearity and obtains a first nonlinear signal. The first nonlinear signal enters the nonlinear load circuit. At this time, the signal obtains a larger nonlinearity and forms a third branch signal. The second branch signal enters the variable load circuit and can generate a different linear signal, namely, the fourth branch signal. In this embodiment, since the impedance of port 2 of the coupler and port 3 of the coupler is 50 ohms, the impedance value of the nonlinear branch and the variable load circuit is not 50 ohms, and the third branch signal and the fourth branch signal will be reflected back to port 4 of the coupler for vector synthesis and output.

[0040] like Figure 3 As shown, in one embodiment, the nonlinear impedance matching network includes a first bias circuit, a first Schottky diode SBD1, a first microstrip line W1 and a DC blocking capacitor C; the common connection end of the first bias circuit and the first microstrip line W1 is connected to the positive electrode of the first Schottky diode SBD1, the negative electrode of the first Schottky diode SBD1 is grounded, and the other end of the first microstrip line W1 is connected to the nonlinear load circuit through the DC blocking capacitor C; wherein the common connection end of the first bias circuit and the first microstrip line W1 serves as the input end of the first branch signal; the first bias circuit is used to generate a first bias voltage for the first Schottky diode SBD1.

[0041] It can be understood that the first bias circuit is a circuit in the art that can generate a bias voltage, the first Schottky diode SBD1, the first microstrip line W1 and the DC blocking capacitor C are traditional conventional devices in the art, and the specific models can be selected according to the characteristics of the transmission signal in the actual application scenario.

[0042] Specifically, the first bias circuit generates a bias voltage for the first Schottky diode SBD1, the first microstrip line W1 and the first Schottky diode SBD1 provide impedance, and the DC blocking capacitor C blocks direct current.

[0043] like Figure 3As shown, in one embodiment, the first bias circuit includes a first RF choke inductor L1, a first resistor R1 and a first voltage source U1; one end of the first RF choke inductor L1 serves as a common connection end with the first microstrip line W1, and the other end is connected to the first voltage source U1 through the first resistor R1.

[0044] It can be understood that the above-mentioned first RF choke inductor L1, first resistor R1 and first voltage source U1 are all conventional signal processing devices in this field. The specific type and model of each device can be selected according to the needs of linear processing of the input signal and application cost in the actual application scenario.

[0045] Specifically, the first branch signal of port 2 of the coupler first enters the nonlinear impedance matching network. Since the voltage of the first voltage source U1 is small at this time, the nonlinear impedance matching network is in a low bias voltage state, usually the low bias voltage is less than 0.5V, and the corresponding first Schottky diode SBD1 is not turned on. At this time, the signal only obtains weak nonlinearity, and then enters the nonlinear load circuit after being blocked by the DC blocking capacitor C.

[0046] The nonlinearity provided by the nonlinear impedance matching network makes it possible to adjust the shape of the signal amplitude compensation curve, that is, by adjusting the voltage of the first voltage source U1, the function of adjusting the shape of the amplitude compensation curve while keeping the compensation amount unchanged is achieved.

[0047] like Figure 3 As shown, in this embodiment, the nonlinear load circuit includes a second bias circuit, a second Schottky diode SBD2, a second microstrip line W2 and a second resistor R2; the common connection end of the second bias circuit and the second microstrip line W2 is connected to the positive electrode of the second Schottky diode SBD2, the negative electrode of the second Schottky diode SBD2 is grounded, and the other end of the second microstrip line W2 is grounded through the second resistor R2; the common connection end of the second bias circuit and the second microstrip line W2 is connected to the output end of the nonlinear impedance matching network; the second bias circuit is used to generate a second bias voltage for the second Schottky diode SBD2.

[0048] It can be understood that the second bias circuit is a circuit in the art that can generate a bias voltage, and the second Schottky diode SBD2, the second microstrip line W2 and the second resistor R2 are traditional conventional devices in the art. The specific models can be selected according to the characteristics of the transmission signal in the actual application scenario.

[0049] Specifically, the first bias circuit generates a bias voltage for the second Schottky diode SBD2, and the second Schottky diode SBD2, the second microstrip line W2 and the second resistor R2 provide impedance.

[0050] By setting the nonlinear load circuit, the overall signal of the nonlinear branch can have the required amplitude and phase distortion characteristics, thereby realizing the linearization function.

[0051] like Figure 3 As shown, in this embodiment, the second bias circuit includes a second RF choke inductor L2, a third resistor R3 and a second voltage source U2; one end of the second RF choke inductor L2 serves as a common connection end with the second microstrip line W2, and the other end is connected to the second voltage source U2 through the third resistor R3.

[0052] It can be understood that the above-mentioned second RF choke inductor L2, third resistor R3 and second voltage source U2 are all conventional signal processing devices in this field. The specific type and model of each device can be selected according to the needs of linear processing of the input signal and application cost in the actual application scenario.

[0053] Specifically, the first nonlinear signal enters the nonlinear load circuit, the second voltage source U2 is set to 2.6V, the corresponding second Schottky diode SBD2 is normally turned on, the signal obtains nonlinear characteristics, and the signal is reflected to the ground line through the resistor to become a third branch signal. Combined with the previous nonlinear impedance matching network, the nonlinear branch can adjust the shape of the amplitude compensation curve while the compensation amount remains unchanged by adjusting the voltage of the first voltage source U1.

[0054] like Figure 5 As shown, the nonlinear branch impedance change curve provided by the embodiment of the utility model. When the voltage of the second voltage source U2 in the nonlinear load circuit is constant, as the voltage value V3 of the first voltage source U1 in the nonlinear impedance matching network changes, the starting point and the end point of the impedance change curve remain almost unchanged, that is, the impedance characteristics of the nonlinear branch at low input power and maximum input power remain basically unchanged, but when the input power gradually increases and does not reach the maximum input power, the change trends of the three curves are different. It can be further deduced that in the input power range, as the bias voltage V3 of the nonlinear impedance matching network changes, the amplitude and phase compensation amount of the reflective predistortion circuit remains almost unchanged, but its gain and phase change characteristics change, that is, the amplitude and phase compensation shape of the circuit is adjustable.

[0055] like Figure 6 , Figure 7 As shown, the curve diagram of gain change and phase change of the nonlinear branch under different bias voltages provided by the embodiment of the utility model. When the voltage of the second voltage source U2 in the nonlinear load circuit is constant, as the voltage value V3 of the first voltage source U1 in the nonlinear impedance matching network changes, the gain compensation amount of the linearizer is maintained at 3.7dB, and the phase compression is maintained at 22°, but the shape of the compensation curve changes with the bias voltage of the nonlinear impedance matching network, that is, the shape of the amplitude compensation curve can be adjusted by adjusting the bias voltage of the nonlinear impedance matching network.

[0056] like Figure 4 As shown, in this embodiment, the variable load circuit includes a third bias circuit, a third microstrip line W3, a fourth microstrip line W4, a fifth microstrip line W5, a first varactor diode VD1 and a second varactor diode VD2; the common connection end of the third microstrip line W3 and the third bias circuit is connected to the fourth microstrip line W4, the other end of the third microstrip line W3 is connected to the cathode of the first varactor diode VD1, and the anode of the first varactor diode VD1 is grounded; the other end of the fourth microstrip line W4 is connected to the cathode of the second varactor diode VD2 through the fifth microstrip line W5, and the anode of the second varactor diode VD2 is grounded; wherein, the common connection end of the third microstrip line W3 and the third bias circuit serves as the input end of the second branch signal; the third bias circuit is used to generate a third bias voltage for the first varactor diode VD1 and the second varactor diode VD2.

[0057] It can be understood that the third bias circuit is a circuit in the art that can generate a bias voltage, and the third microstrip line W3, the fourth microstrip line W4, the fifth microstrip line W5, the first varactor diode VD1 and the second varactor diode VD2 are traditional conventional devices in the art, and the specific models can be selected according to the characteristics of the transmission signal in the actual application scenario.

[0058] Specifically, the third bias circuit provides bias voltage for the first varactor diode and the second varactor diode, and the third microstrip line W3, the fourth microstrip line W4, the fifth microstrip line W5, the first varactor diode VD1 and the second varactor diode VD2 provide impedance for the variable load circuit to generate a linear signal.

[0059] like Figure 4 As shown, in this embodiment, the third bias circuit includes a third RF choke inductor L3 and a third voltage source U3; one end of the third RF choke inductor L3 serves as a common connection end with the third microstrip line W3, and the other end is connected to the third voltage source U3.

[0060] It can be understood that the above-mentioned third RF choke inductor L3 and third voltage source U3 are both conventional signal processing devices in this field. The specific type and model of each device can be selected according to the needs of linear processing of the input signal and application cost in the actual application scenario.

[0061] Specifically, the second branch signal of the port 3 of the coupler enters the variable load circuit, which changes the impedance of the varactor diode by adjusting the voltage V2 of the third voltage source U3, thereby generating different linear signals, and the signal is reflected to the ground to form a fourth branch signal. After the third branch signal and the fourth branch signal are synthesized, the linear signal generated by the variable load circuit can achieve amplitude compensation and remain unchanged, and the phase compensation is independently adjusted with the bias voltage V2 of the variable load.

[0062] like Figure 8 As shown in the figure, the equal gain compensation amount curve and equal phase compensation amount curve of the asymmetric analog predistortion linearizer provided by the embodiment of the utility model at the center frequency (11.7GHz). When the bias voltage of the nonlinear branch is determined, the overall amplitude phase compensation is only related to the voltage of the third voltage source U3 of the variable load circuit of the linear main circuit. By adjusting the voltage V2 of the third voltage source U3 in the variable load circuit, the impedance of the variable load circuit is changed by Figure 4 A in the figure moves to C. At this time, the gain compensation of the circuit is always 4.2dB, and the phase compression is reduced from 27° to 11°. That is, the independent tuning of the phase compensation can be achieved by adjusting the bias voltage of the variable load circuit.

[0063] like Fig. 9 , 10 As shown, the curve diagram of gain change and phase change of the linear branch under different bias voltages provided by the utility model example. As the voltage V2 of the third voltage source U3 in the variable load circuit changes, the gain compensation amount of the analog predistortion linearizer remains unchanged at 4.2dB, and the phase compression decreases from 27° to 11° as the voltage V2 of the third voltage source U3 in the variable load circuit increases, that is, the phase compensation can be independently adjustable by adjusting the bias voltage of the variable load circuit.

[0064] It can be seen from the above embodiments that the asymmetric reflective analog predistortion linearizer with multiple adjustable functions provided by the utility model can realize independent regulation of phase compensation by adjusting the bias voltage of the variable load in the circuit, and can realize the unchanged amplitude compensation amount and independent adjustable curve shape by adjusting the bias voltage of the nonlinear impedance matching network in the circuit. Compared with the existing analog predistortion linearizer, the asymmetric reflective structure adopted by the utility model can expand the flexibility and realize more flexible and accurate linearization of the power amplifier.

[0065] Finally, it should be noted that the above-mentioned embodiments are only specific implementation methods of the utility model, which are used to illustrate the technical solution of the utility model, rather than to limit it. The protection scope of the utility model is not limited thereto. Although the utility model is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the field can still modify the technical solution recorded in the above-mentioned embodiments within the technical scope disclosed by the utility model, or can easily think of changes, or replace some of the technical features therein by equivalents; and these modifications, changes or replacements do not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solution of the embodiment of the utility model, and should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. An asymmetric reflective analog predistortion linearizer with multiple adjustabilities, characterized in that: Includes couplers, nonlinear branches, and variable load circuits; The coupler is used to separate the input signal into a first branch signal and a second branch signal; The nonlinear branch is used to adjust the shape of the amplitude compensation curve of the first branch signal to obtain a third branch signal; The variable load circuit is used to adjust the phase compensation of the second branch signal to obtain a fourth branch signal; The coupler is also used to synthesize the third branch signal and the fourth branch signal to obtain a linearized output signal.

2. The asymmetric reflective analog predistortion linearizer with multiple adjustabilities according to claim 1, characterized in that: The nonlinear branch includes a nonlinear impedance matching network and a nonlinear load circuit connected in series; The nonlinear impedance matching network is used to provide a nonlinearly changing impedance network to adjust the first branch signal to obtain a first nonlinear signal; The nonlinear load circuit is used to provide a nonlinear load to adjust the first nonlinear signal to obtain a third branch signal.

3. The asymmetric reflective analog predistortion linearizer with multiple adjustabilities according to claim 2, characterized in that: The coupler comprises four ports, wherein the port (1) of the coupler is used to receive an input signal, the port (2) of the coupler is connected to the input end of the nonlinear impedance matching network, the port (3) of the coupler is connected to the input end of the variable load circuit, and the port (4) of the coupler is used to output a linearized output signal.

4. The asymmetric reflective analog predistortion linearizer with multiple adjustabilities according to claim 2, characterized in that: The nonlinear impedance matching network includes a first bias circuit, a first Schottky diode, a first microstrip line and a DC blocking capacitor; The common connection end of the first bias circuit and the first microstrip line is connected to the positive electrode of the first Schottky diode, the negative electrode of the first Schottky diode is grounded, and the other end of the first microstrip line is connected to the nonlinear load circuit through the DC blocking capacitor; wherein the common connection end of the first bias circuit and the first microstrip line serves as the input end of the first branch signal; and the first bias circuit is used to generate a first bias voltage for the first Schottky diode.

5. The asymmetric reflective analog predistortion linearizer with multiple adjustabilities according to claim 4, characterized in that: The first bias circuit includes a first radio frequency choke inductor, a first resistor and a first voltage source; One end of the first radio frequency choke inductor serves as a common connection end with the first microstrip line, and the other end is connected to a first voltage source via a first resistor.

6. The asymmetric reflective analog predistortion linearizer with multiple adjustabilities according to claim 2, characterized in that: The nonlinear load circuit includes a second bias circuit, a second Schottky diode, a second microstrip line and a second resistor; The common connection end of the second bias circuit and the second microstrip line is connected to the positive electrode of the second Schottky diode, the negative electrode of the second Schottky diode is grounded, and the other end of the second microstrip line is grounded through the second resistor; wherein the common connection end of the second bias circuit and the second microstrip line is connected to the output end of the nonlinear impedance matching network; the second bias circuit is used to generate a second bias voltage for the second Schottky diode.

7. The asymmetric reflective analog predistortion linearizer with multiple adjustabilities according to claim 6, characterized in that: The second bias circuit includes a second radio frequency choke inductor, a third resistor and a second voltage source; One end of the second radio frequency choke inductor serves as a common connection end with the second microstrip line, and the other end is connected to a second voltage source via a third resistor.

8. The asymmetric reflective analog predistortion linearizer with multiple adjustabilities according to claim 1, characterized in that: The variable load circuit includes a third bias circuit, a third microstrip line, a fourth microstrip line, a fifth microstrip line, a first varactor diode and a second varactor diode; The common connection end of the third microstrip line and the third bias circuit is connected to the fourth microstrip line, the other end of the third microstrip line is connected to the cathode of the first varactor diode, and the anode of the first varactor diode is grounded; the other end of the fourth microstrip line is connected to the cathode of the second varactor diode through the fifth microstrip line, and the anode of the second varactor diode is grounded; wherein the common connection end of the third microstrip line and the third bias circuit serves as the input end of the second branch signal; the third bias circuit is used to generate a third bias voltage for the first varactor diode and the second varactor diode.

9. The asymmetric reflective analog predistortion linearizer with multiple adjustabilities according to claim 8, characterized in that: The third bias circuit includes a third radio frequency choke inductor and a third voltage source; One end of the third radio frequency choke inductor serves as a common connection end with the third microstrip line, and the other end is connected to a third voltage source.

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