Reconfigurable load modulation balanced amplifier

Abstract

The invention discloses a reconfigurable load modulation balanced amplifier. The power amplifier comprises an input port, a first input coupler, a second input coupler, a phase switching network, a control amplifier, a first balance amplifier, a second balance amplifier, an output coupler and an output port. The straight-through end of the first input coupler is sequentially connected with the phase switching network and the control amplifier; the coupling end of the first input coupler is sequentially connected with the second input coupler; the straight-through end of the second input coupler is sequentially connected with the first balanced amplifier circuit; the coupling end of the second input coupler is sequentially connected with the second balanced amplifier circuit. Phase switching is carried out through the phase switching network at the input end, compared with a load modulation balanced amplifier with a fixed phase, switching of two different working modes can be achieved, the working bandwidth of the load modulation balanced amplifier is expanded, and meanwhile the output power and efficiency of the power amplifier cannot be affected by loss of the phase switching network.

Description

Technical Field

[0001] The invention belongs to the technical field of wireless communications, and in particular relates to a reconfigurable load modulation balanced amplifier. Background Art

[0002] As wireless communication standards evolve towards the next generation (i.e., 5G), the increasing data rates and spectral efficiency result in higher peak-to-average power ratios (PAPRs) of communication signals (e.g., >10dB for the latest WLAN signals). This requires efficient power amplifiers (PAs) with higher output power and back-off efficiency. Load modulation has always been one of the main techniques for improving PA efficiency, and there are a variety of classic circuit architectures that can be used for the practical implementation of load modulation, such as Doherty PA, out-of-phase or Chirex PA, and varactor-based dynamic load modulation (DLM). Although these techniques have been widely demonstrated, there is still a trade-off between efficiency, power back-off range, bandwidth, etc. In recent years, a new PA architecture based on active load modulation using a balanced amplifier (BA) configuration has been proposed. By injecting an additional signal into the isolated port of the output quadrature coupler, the load impedance of the BA device can be controlled by the change of the amplitude and phase of this signal, thereby achieving load modulation behavior and improving the back-off efficiency.

[0003] The existing IEEE Transactions on Microwave Theory and Techniques article Pseudo-Doherty Load Modulated Balanced Amplifier With Wide Bandwidth and Extended Power Back-Off Range proposes a load modulated balanced amplifier. The structure diagram is as follows Figure 1As shown in the figure, the power divider divides the input signal into two paths and simultaneously enters the control amplifier (biased in class AB) and two balanced amplifiers (biased in class C). By setting the appropriate power ratio and phase offset between the control amplifier and the balanced amplifier, the balanced amplifier can be actively load modulated, thereby improving the back-off efficiency and back-off range of the power amplifier. Its basic working principle is divided into two states: (1) Low power state: The balanced amplifier has not yet turned on, and its output end is in an open circuit state. At this time, only the main amplifier is working, and the main amplifier enters the saturation state, and the efficiency is the highest. (2) High power state: The balanced amplifier is in the on state, and the balanced amplifier and the control amplifier work at the same time. When the voltage is maintained at saturation, the output power increases further, and finally both enter the saturation state and achieve the highest efficiency. The power ratio of the control amplifier to the balanced amplifier is 1:1.53, and the power back-off range is 10dB. However, the phase transformation of the conventional load-modulated balanced amplifier usually requires the redesign of the matching circuit, which is relatively complicated and difficult to operate in actual operation. In addition, the conventional load-modulated balanced amplifier is difficult to achieve reconfigurable functions due to the complex load matching at the output end.

[0004] Regarding the research on reconfigurable load-modulated balanced amplifiers, in the existing reconfigurable power amplifier designs, the method of achieving reconfiguration is mostly to add branches to the input or output matching network. Sometimes, multiple branches need to be added to change the matching network structure through the conduction of switches to achieve bandwidth expansion or frequency band switching. At the same time, the current research on the reconfigurability of load-modulated balanced amplifiers is not in-depth, and the existing reconfigurable implementation methods often have the following problems: (1) The existing reconfigurable implementation methods generally add branches to the matching network to perform matching transformations, which often increases the amount of calculation. Taking the load modulation process as an example, it will make the matching of the balanced amplifier more difficult and bring unnecessary trouble. (2) The existing reconfigurable implementation methods are generally used in single-transistor power amplifiers. When facing a multi-transistor power amplifier structure with more stringent matching conditions, the design of the reconfigurable structure is more difficult and easy to interfere with the existing structure. (3) If the reconfigurable structure is designed to be relatively simple, it may be prone to deviation due to excessive bandwidth; if the design is too complex, such as being connected in parallel in the matching circuit, it may affect the circuit when it is not turned on. (4) If a reconfigurable structure is used in the output matching network, it may affect the overall output power and efficiency of the power amplifier.

[0005] In view of the above problems and in combination with the characteristics of the load-modulated balanced amplifier, the present invention provides a new structure of a reconfigurable load-modulated balanced amplifier in order to reduce the excessive impact of the reconfigurable structure on the matching network and simplify the design difficulty. The phase of the input end is adjusted by a phase switching network formed by two single-pole double-throw switches, so as to realize the switching of the load-modulated balanced amplifier between broadband and dual-band working modes, thereby meeting the needs of high-efficiency amplification of modulation signals of different standards in future wireless communication systems. Summary of the invention

[0006] The purpose of the present invention is to provide a reconfigurable load-modulated balanced amplifier, that is, by performing phase switching in a phase switching network at the input end, compared with a load-modulated balanced amplifier with a fixed phase, switching between two different operating modes can be achieved, thereby expanding the operating bandwidth of the load-modulated balanced amplifier, and at the same time, the loss of the phase switching network will not affect the output power and efficiency of the power amplifier.

[0007] In order to achieve the above-mentioned object, the present invention provides a reconfigurable load-modulated balanced power amplifier, comprising: an input port (10), a first input coupler (20), a phase switching network (30), a second input coupler (40), a control amplifier (50), a first balanced amplifier (60), a second balanced amplifier (70), an output coupler (80) and an output port (90); characterized in that: the input port (10) is connected to the input end of the first input coupler (20), the through end of the first input coupler (20) is connected to the input end of the phase switching network (30), the coupling end is connected to the input end of the second input coupler (40), and the isolation end is connected to a 50Ω resistor and then grounded; the output end of the phase switching network (30) is connected to the control amplifier (50); the through end of the second input coupler (40) is connected to the first balanced amplifier (60), the coupling end is connected to the second balanced amplifier (70), and the isolation end is connected to a 50Ω resistor and then grounded; the control The amplifier (50) is composed of a control amplifier input matching network (501), a control amplifier power amplifier tube (502) and a control amplifier output matching network (503) connected in series; the first balanced amplifier (60) is composed of a first balanced amplifier input matching network (601), a first balanced amplifier power amplifier tube (602) and a first balanced amplifier output matching network (603) connected in series; the second balanced amplifier (70) is composed of a second balanced amplifier input matching network (701), a second balanced amplifier power amplifier tube (702) and a second balanced amplifier output matching network (703) connected in series; the output end of the control amplifier (50) is connected to the isolation end of the output coupler (80), the first balanced amplifier (60) is connected to the coupling end of the output coupler (80), and the second balanced amplifier (70) is connected to the through end of the output coupler (80); the input end of the output coupler (80) is connected to the output port (90).

[0008] Furthermore, the first input coupler (20) outputs the input signal as a main signal and an auxiliary signal at a power ratio of 1:1, wherein the auxiliary signal output at the coupling end is phase delayed by -90° compared to the main signal output at the through end, the main signal is output to the control amplifier (50) through the phase switching network (30), and the auxiliary signal is output to the second input coupler (40).

[0009] Furthermore, the second input coupler (40) outputs the input signal as an auxiliary channel up signal and an auxiliary channel down signal at a power ratio of 1:1, wherein the auxiliary channel down signal output at the coupling end is phase delayed by -90° compared to the auxiliary channel up signal output at the through end, the auxiliary channel up signal is output to the first balanced amplifier (60), and the auxiliary channel down signal is output to the second balanced amplifier (70).

[0010] Furthermore, the phase switching network (30) comprises a first single-pole double-throw switch K1 (301) and a second single-pole double-throw switch K2 (304), a first phase shift line (302) and a second phase shift line (303); wherein the upper fixed end A of the first single-pole double-throw switch K1 (301) is connected to the input end of the first phase shift line (302), the lower fixed end B is connected to the input end of the second phase shift line (303), and the active end C is connected to the through end of the first input coupler (20); the second single-pole double-throw switch K2 (304) is connected to the input end of the second phase shift line (303); The upper fixed end D of the throw switch K2 (304) is connected to the output end of the first phase shift line (302), the lower fixed end E is connected to the output end of the second phase shift line (303), and the active end F is connected to the input end of the control amplifier (50); the characteristic impedance of the first phase shift line (302) in the phase switching network (30) is 50Ω, providing a phase shift of 0°; the characteristic impedance of the second phase shift line (303) in the phase switching network (30) is 50Ω, providing a phase shift of -180°.

[0011] Furthermore, the phase switching network (30) has two states: 0° phase shift and -180° phase shift. When the phase switching network (30) is in the 0° phase shift state, the active end C of the first single-pole double-throw switch K1 (301) is connected to the upper fixed end A, and the active end F of the second single-pole double-throw switch K1 (304) is connected to the upper fixed end D. The reconfigurable load-modulated balanced amplifier can achieve high output power, high saturation efficiency and high back-off efficiency in a wider frequency band, that is, it works in a broadband mode. When the phase switching network (30) is in the -180° phase shift state, the active end C of the first single-pole double-throw switch K1 (301) is connected to the lower fixed end B, and the active end F of the second single-pole double-throw switch K1 (304) is connected to the lower fixed end E. The reconfigurable balanced amplifier can achieve high output power, high saturation efficiency and high back-off efficiency in both high and low frequency bands, that is, it works in a dual-band mode. The first single-pole double-throw switch K1 (301) and the second single-pole double-throw switch K2 (304) can switch working states simultaneously.

[0012] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: (1) The present invention adopts the load-modulated balanced amplifier structure proposed in recent years. The overall power amplifier consists of a control power amplifier and a balanced power amplifier. Compared with the relatively fixed phase of a conventional load-modulated balanced amplifier, the present invention adds a phase switching network at the input end of the control amplifier to achieve phase adjustment through the phase switching network, thereby enabling the amplifier to switch between broadband mode and dual-band mode, achieving reconfigurable working mode and effectively broadening the working bandwidth of the load-modulated balanced amplifier.

[0013] (2) The reconfigurable method of the present invention is simpler than other methods for implementing reconfigurable matching networks, which simplifies the design process and reduces the design difficulty. At the same time, the circuit structure used to achieve reconfiguration is located at the input end, and its loss does not affect the output power and efficiency of the overall power amplifier, which greatly improves the scope of use of the reconfigurable structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the structure of a conventional load-modulated balanced amplifier.

[0015] Figure 2 A schematic diagram of the structure of a reconfigurable load modulation balanced amplifier used in the present invention.

[0016] Figure 3 A schematic diagram of the structure of a phase switching network used in the present invention.

[0017] Figure 4 The working flow chart of the reconfigurable load modulation balanced amplifier adopted by the present invention.

[0018] Figure 5 A graph showing the relationship between the drain efficiency and the saturated output power of the reconfigurable load modulated balanced amplifier in the broadband mode when saturated and 10 dB back-off are compared with the frequency in the embodiment of the present invention.

[0019] Figure 6 A relationship diagram of gain, efficiency and output power at three frequencies of low, medium and high when the reconfigurable load-modulated balanced amplifier in the embodiment of the present invention is in broadband mode.

[0020] Figure 7 A graph showing the relationship between saturation, drain efficiency at 10 dB back-off, and saturated output power versus frequency for a reconfigurable load modulated balanced amplifier in a dual-band mode according to an embodiment of the present invention.

[0021] Figure 8 A relationship diagram of gain, efficiency and output power when the reconfigurable load-modulated balanced amplifier is in dual-band mode in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0023] Figure 2The present invention shows a reconfigurable load modulated balanced amplifier, comprising an input port (10), a first input coupler (20), a phase switching network (30), a second input coupler (40), a control amplifier (50), a first balanced amplifier (60), a second balanced amplifier (70), an output coupler (80) and an output port (90); the input port (10) is connected to the input end of the first input coupler (20); the through end of the first input coupler (20) is connected to the input end of the phase switching network (30); the coupling end is connected to the input end of the second input coupler (40); the isolation end is connected to a 50Ω resistor and then grounded; the output end of the phase switching network (30) is connected to the control amplifier (50); the through end of the second input coupler (40) is connected to the first balanced amplifier (60); the coupling end is connected to the second balanced amplifier (70); the isolation end is connected to a 50Ω resistor and then grounded; the control amplifier (5 0) is composed of a control amplifier input matching network (501), a control amplifier power amplifier tube (502) and a control amplifier output matching network (503) connected in series; the first balanced amplifier (60) is composed of a first balanced amplifier input matching network (601), a first balanced amplifier power amplifier tube (602) and a first balanced amplifier output matching network (603) connected in series; the second balanced amplifier (70) is composed of a second balanced amplifier input matching network (701), a second balanced amplifier power amplifier tube (702) and a second balanced amplifier output matching network (703) connected in series; the output end of the control amplifier (50) is connected to the isolation end of the output coupler (80), the first balanced amplifier (60) is connected to the coupling end of the output coupler (80), and the second balanced amplifier (70) is connected to the through end of the output coupler (80); the input end of the output coupler (80) is connected to the output port (90).

[0024] In the above-mentioned load-modulated balanced amplifier, the first input coupler (20) outputs the input signal as a main signal and an auxiliary signal at a power ratio of 1:1, wherein the auxiliary signal output at the coupling end is phase-delayed by -90° compared to the main signal output at the through end, the main signal is output to the control amplifier (50) through the phase switching network (30), and the auxiliary signal is output to the second input coupler (40).

[0025] In the above-mentioned load-modulated balanced amplifier, the second input coupler (40) outputs the auxiliary signal as an auxiliary up signal and an auxiliary down signal at a power ratio of 1:1, wherein the auxiliary down signal output at the coupling end is phase-delayed by -90° compared to the auxiliary up signal output at the through end, the auxiliary up signal is output to the first balanced amplifier (60), and the auxiliary down signal is output to the second balanced amplifier (70).

[0026] like Figure 3 As shown in the schematic diagram of the phase switching network structure, the phase switching network (30) comprises a first single-pole double-throw switch K1 (301) and a second single-pole double-throw switch K2 (304), a first phase shift line (302) and a second phase shift line (303); wherein the upper fixed end A of the first single-pole double-throw switch K1 (301) is connected to the input end of the first phase shift line (302), the lower fixed end B is connected to the input end of the second phase shift line (303), and the active end C is connected to the through end of the first input coupler (20); the second The upper fixed end D of the single-pole double-throw switch K2 (304) is connected to the output end of the first phase shift line (302), the lower fixed end E is connected to the output end of the second phase shift line (303), and the active end F is connected to the input end of the control amplifier (50); the characteristic impedance of the first phase shift line (302) in the phase switching network (30) is 50Ω, providing a phase shift of 0°; the characteristic impedance of the second phase shift line (303) in the phase switching network (30) is 50Ω, providing a phase shift of -180°.

[0027] In the above-mentioned load-modulated balanced amplifier, the phase switching network (30) has two states: 0° phase shift and -180° phase shift; when the phase switching network (30) is in the 0° phase shift state, the active end C of the first single-pole double-throw switch K1 (301) is connected to the fixed end A, and the active end F of the second single-pole double-throw switch K1 (304) is connected to the fixed end D; the reconfigurable load-modulated balanced amplifier can achieve high output power, high saturation efficiency and high back-off efficiency in a wider frequency band, that is, The invention works in broadband mode; when in a -180° phase shift state, the active end C of the first single-pole double-throw switch K1 (301) is connected to the lower fixed end B, and the active end F of the second single-pole double-throw switch K1 (304) is connected to the lower fixed end E; the reconfigurable balanced amplifier can achieve high output power, high saturation efficiency and high back-off efficiency in both high and low frequency bands, that is, it works in dual-band mode; the first single-pole double-throw switch K1 (301) and the second single-pole double-throw switch K2 (304) can switch working states at the same time.

[0028] Figure 4 This is a working flow chart of the reconfigurable load modulation balanced amplifier used in the present invention, and the specific process is as follows: (1) An input signal enters the first input coupler (20) from the input port (10).

[0029] (2) The signal is equally divided into two signals, a main signal and an auxiliary signal, through the first input coupler (20). The auxiliary signal enters the input end of the second input coupler (40), and the main signal enters the input end of the phase switching network (30).

[0030] (3) When the phase switching network (30) is switched to the broadband mode, the signal enters the phase switching network (30) and undergoes phase transformation through the first phase shift line (302). At this time, the load-modulated balanced amplifier operates in the broadband mode.

[0031] (4) When the phase switching network (30) is switched to the dual-band mode, the signal enters the phase switching network (30) and undergoes phase transformation through the second phase shift line (303), and the load-modulated balanced amplifier now operates in the dual-band mode.

[0032] (5) The main signal passes through the phase switching network (30) and then passes through the control amplifier (50), while the auxiliary signal passes through the second output coupler (40) and is divided into an auxiliary upper signal and an auxiliary lower signal. The auxiliary upper signal enters the first balanced amplifier (60), and the auxiliary lower signal enters the second balanced amplifier (70).

[0033] (6) The amplified signals of the three outputs are power-synthesized by the output coupler (80), wherein the main signal amplified by the control amplifier (50) enters the isolation end of the output coupler (80), the auxiliary signal amplified by the first balanced amplifier (60) enters the coupling end of the output coupler (80), and the auxiliary signal amplified by the second balanced amplifier (70) enters the through end of the output coupler (80).

[0034] (7) The synthesized signal is output from the output port (90).

[0035] An embodiment is listed below. It should be pointed out that the purpose of the present invention is to propose an innovative structure, and the present invention is still applicable to transistor devices and switch devices for other signals; the first input coupler in the structure of the present invention can also be replaced by other circuit devices for power distribution such as power dividers, and the second input coupler and the output coupler can use commercial couplers or self-designed ones. It should be noted that the phase changes at each port of the output coupler, and if conditions permit, a suitable microstrip line can be added at the input end for phase compensation.

[0036] The following are only preferred embodiments of the invention and are not intended to limit the invention. Various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the invention. Any modifications, equivalent substitutions, improvements, etc. made within the conceptual principles of the invention should be included in the protection scope of the invention.

[0037] In the reconfigurable load modulated balanced amplifier of this embodiment, the control amplifier power amplifier tube (502), the first balanced amplifier power amplifier tube (602), and the second balanced amplifier power amplifier tube (702) all adopt CREE's GAN HEMT power amplifier tube. The control amplifier power amplifier tube (502) is biased in class AB, and the first balanced amplifier power amplifier tube (602) and the second balanced amplifier power amplifier tube (702) are biased in class C. When the phase switching network (30) is switched to broadband mode, the operating frequency of the reconfigurable load modulated balanced amplifier is 1.7-2.7 GHz; when the phase switching network (30) is switched to dual-band mode, the operating frequency of the reconfigurable load modulated balanced amplifier is 1.2-1.7 GHz and 2.7-3.1 GHz.

[0038] Figure 5 The figure shows the relationship between the drain efficiency and saturated output power of the reconfigurable load modulated balanced amplifier in saturation, 10dB back-off and frequency. The line with hollow circles represents the drain efficiency in saturation, the line with solid squares represents the drain efficiency with 10dB back-off, and the line with solid triangles represents the saturated output efficiency. Figure 6 The figure is a relationship diagram of gain, efficiency and output power at three frequencies of low, medium and high when the reconfigurable load modulated balanced amplifier in the embodiment of the present invention is in broadband mode, wherein the line with solid squares represents the gain and efficiency versus output power variation curve at 1.7GHz, the line with hollow circles represents the gain and efficiency versus output power variation curve at 2.1GHz, the line with solid regular triangles represents the gain and efficiency versus output power variation curve at 2.3GHz, and the line with hollow inverted triangles represents the gain and efficiency versus output power variation curve at 2.7GHz. It can be seen from the figure that the drain efficiency of the reconfigurable load modulated balanced amplifier is between 58% and 77% when saturated within the 1.7-2.7GHz frequency band, and the drain efficiency is between 42% and 67% when backed off by 10dB.

[0039] Figure 7 The figure is a graph showing the relationship between the drain efficiency at saturation, 10 dB back-off, and saturated output power as a function of frequency when the reconfigurable load-modulated balanced amplifier in the dual-band mode is in an embodiment of the present invention, wherein the line with a hollow circle represents the drain efficiency at saturation, the line with a solid square represents the drain efficiency at 10 dB back-off, and the line with a solid triangle represents the saturated output efficiency. Figure 8The figure is a graph showing the relationship between gain, efficiency and output power of the reconfigurable load modulated balanced amplifier in the dual-band mode in the embodiment of the present invention, wherein the line with solid squares represents the gain and efficiency versus output power curve at 1.2GHz, the line with hollow circles represents the gain and efficiency versus output power curve at 1.7GHz, the line with solid regular triangles represents the gain and efficiency versus output power curve at 2.8GHz, and the line with hollow inverted triangles represents the gain and efficiency versus output power curve at 3.1GHz. It can be seen from the figure that the drain efficiency of the reconfigurable load modulated balanced amplifier in the dual-band is between 55% and 82% when saturated, and between 41% and 59% when backed off by 10dB.

[0040] It can be seen that by switching the phase switching network mode, the load modulated balanced amplifier can effectively broaden the bandwidth of the power amplifier while maintaining high efficiency.

Claims

1. A reconfigurable load-modulated balanced amplifier, include: An input port (10), a first input coupler (20), a phase switching network (30), a second input coupler (40), a control amplifier (50), a first balanced amplifier (60), a second balanced amplifier (70), an output coupler (80) and an output port (90); characterized in that: the input port (10) is connected to the input end of the first input coupler (20); the through end of the first input coupler (20) is connected to the input end of the phase switching network (30); the coupling end is connected to the input end of the second input coupler (40); the isolation end is connected to a 50Ω resistor and then grounded; the output end of the phase switching network (30) is connected to the control amplifier (50); the through end of the second input coupler (40) is connected to the first balanced amplifier (60); the coupling end is connected to the second balanced amplifier (70); the isolation end is connected to a 50Ω resistor and then grounded; the control amplifier (50) is connected to the control amplifier input matching network The invention relates to a device for controlling a first balanced amplifier (500) and a second balanced amplifier (700) comprising a first balanced amplifier input matching network (501), a first balanced amplifier power amplifier tube (502) and a first balanced amplifier output matching network (603) connected in series; the first balanced amplifier (60) comprises a first balanced amplifier input matching network (601), a first balanced amplifier power amplifier tube (602) and a first balanced amplifier output matching network (603) connected in series; the second balanced amplifier (70) comprises a second balanced amplifier input matching network (701), a second balanced amplifier power amplifier tube (702) and a second balanced amplifier output matching network (703) connected in series; the output end of the control amplifier (50) is connected to the isolation end of the output coupler (80), the first balanced amplifier (60) is connected to the coupling end of the output coupler (80), and the second balanced amplifier (70) is connected to the through end of the output coupler (80); the input end of the output coupler (80) is connected to the output port (90).

2. The reconfigurable load modulated balanced amplifier according to claim 1, Features: The first input coupler (20) outputs the input signal as a main signal and an auxiliary signal at a power ratio of 1:1, wherein the auxiliary signal output at the coupling end is phase-delayed by -90° compared to the main signal output at the through end, the main signal is output to the control amplifier (50) through the phase switching network (30), and the auxiliary signal is output to the second input coupler (40).

3. The reconfigurable load-modulated balanced amplifier according to claim 1, Features: The second input coupler (40) outputs the input signal as an auxiliary channel up signal and an auxiliary channel down signal at a power ratio of 1:1, wherein the auxiliary channel down signal output at the coupling end is phase delayed by -90° compared to the auxiliary channel up signal output at the through end, the auxiliary channel up signal is output to the first balanced amplifier (60), and the auxiliary channel down signal is output to the second balanced amplifier (70).

4. The reconfigurable load modulated balanced amplifier according to claim 1, Features: The phase switching network (30) comprises a first single-pole double-throw switch K1 (301), a second single-pole double-throw switch K2 (304), a first phase shift line (302), and a second phase shift line (303); wherein the upper fixed end A of the first single-pole double-throw switch K1 (301) is connected to the input end of the first phase shift line (302), the lower fixed end B is connected to the input end of the second phase shift line (303), and the active end C is connected to the through end of the first input coupler (20); the second single-pole double-throw switch The upper fixed end D of K2 (304) is connected to the output end of the first phase shift line (302), the lower fixed end E is connected to the output end of the second phase shift line (303), and the active end F is connected to the input end of the control amplifier (50); the characteristic impedance of the first phase shift line (302) in the phase switching network (30) is 50Ω, providing a phase shift of 0°; the characteristic impedance of the second phase shift line (303) in the phase switching network (30) is 50Ω, providing a phase shift of -180°.

5. The reconfigurable load-modulated balanced amplifier according to claim 1, Features: The phase switching network (30) has two states: a 0° phase shift and a -180° phase shift. When the phase switching network (30) is in the 0° phase shift state, that is, the active end C of the first single-pole double-throw switch K1 (301) is connected to the upper fixed end A, and the active end F of the second single-pole double-throw switch K2 (304) is connected to the upper fixed end D, the reconfigurable load-modulated balanced amplifier can achieve high output power, high saturation efficiency and high back-off efficiency in a wider frequency band, that is, it works in a broadband mode. When the phase switching network (30) is in the -180° phase shift state, that is, the active end C of the first single-pole double-throw switch K1 (301) is connected to the lower fixed end B, and the active end F of the second single-pole double-throw switch K2 (304) is connected to the lower fixed end E, the reconfigurable balanced amplifier can achieve high output power, high saturation efficiency and high back-off efficiency in both high and low frequency bands, that is, it works in a dual-band mode. The first single-pole double-throw switch K1 (301) and the second single-pole double-throw switch K2 (304) can switch working states simultaneously.

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