A C-band low harmonic power amplifier

Abstract

The utility model discloses a C wave band low harmonic power amplifier relates to the field of amplifier, and the amplifier includes the phase -locked loop frequency source module, and its output is connected pre -inhibit harmonic filter, adjustable gain forestage amplifier, interstage dynamic harmonic suppression module and double power divider microstrip circuit in proper order. Two output ends of double power divider microstrip circuit are connected first, second final stage power amplifier respectively, and its output is synthesized through double -way power synthesizer microstrip circuit again, and finally by radio frequency port output, while access feedback detection module, under the control of control module, through interstage dynamic harmonic suppression module to harmonic real -time regulation and control, combine the closed -loop feedback mechanism of feedback detection module, and the harmonic distortion caused by temperature drift, device aging is effectively suppressed, and the stability of harmonic suppression performance is significantly improved while guaranteeing high -power output.

Description

Technical Field

[0001] This utility model relates to the field of amplifiers, specifically to a C-band low harmonic power amplifier. Background Technology

[0002] C-band low harmonic power amplifiers are radio frequency power amplifiers used in the C-band (4GHz to 8GHz) and are commonly used in satellite communications and radar systems. Their core feature is low harmonic distortion, which can meet the requirements of communication systems for signal purity and efficiency.

[0003] Existing technology CN211457091U discloses a C-band pulsed power amplifier, which uses drain voltage pulse modulation for control. A drain voltage is applied briefly before the input pulse and removed briefly after the turn-off pulse, achieving reduced power consumption and heat dissipation. However, the filter parameters of this prior art are fixed and cannot be adjusted in real time according to device aging, temperature drift, or load changes. This results in a deterioration in harmonic suppression as operating conditions worsen, making it difficult to meet the requirements for high-purity spectrum. Utility Model Content

[0004] The purpose of this utility model is to provide a C-band low harmonic power amplifier that solves the problem that existing fixed filters cannot adapt to changes in harmonic characteristics.

[0005] To achieve the above objectives, this utility model provides a C-band low harmonic power amplifier, including a phase-locked frequency source module. The output terminal of the phase-locked frequency source module is sequentially connected to a pre-suppressed harmonic filter, an adjustable gain preamplifier, an interstage dynamic harmonic suppression module, and a dual power divider microstrip circuit. The two output terminals of the dual power divider microstrip circuit are respectively connected to the input terminals of a first final-stage power amplifier and a second final-stage power amplifier. The output terminals of the first final-stage power amplifier and the second final-stage power amplifier are respectively connected to the input terminals of a dual-channel power combiner microstrip circuit. The output terminal of the dual-channel power combiner microstrip circuit is connected to an RF output port through an isolator and is also connected to the input terminal of a feedback detection module.

[0006] It also includes a control module, which is connected to the phase-locked frequency source module, the adjustable gain preamplifier, the interstage dynamic harmonic suppression module and the feedback detector module.

[0007] This invention generates a stable fundamental signal through a phase-locked frequency source module. After initial harmonics are filtered out by a pre-suppression harmonic filter, the signal is initially amplified by an adjustable gain preamplifier. An interstage dynamic harmonic suppression module dynamically adjusts the filtering parameters based on the harmonic intensity detection results from the feedback detector module to suppress harmonic components generated by the preamplifier. A dual-power divider microstrip circuit splits the signal into two paths, which are then amplified at high power by the first and second final-stage power amplifiers, respectively, before being combined into an output by a dual-path power combiner microstrip circuit. An isolator prevents damage from load reflection signals. The feedback detector module detects output harmonics in real time and feeds them back to the control module. The control module dynamically adjusts parameters such as interstage harmonic suppression and preamplifier gain based on the detection results, forming an adaptive closed-loop control link. This invention solves the problem of decreased harmonic suppression performance in traditional power amplifiers due to temperature drift and device aging through dynamic harmonic suppression and closed-loop feedback mechanisms, reducing harmonic distortion while ensuring high power output.

[0008] Furthermore, the amplifier also includes an adaptive adjustment unit, which includes a fundamental frequency compensation circuit and a harmonic notch filter circuit.

[0009] The input terminal of the fundamental frequency compensation circuit is connected to the output terminal of the adjustable gain preamplifier via a directional coupler, and the output terminal of the fundamental frequency compensation circuit is connected to the input terminal of the power divider microstrip circuit.

[0010] The input terminal of the harmonic notch circuit is connected to the harmonic intensity detection port of the feedback detection module, and the output terminal of the harmonic notch circuit is connected to the input terminal of the dual-channel power combiner microstrip circuit through a digitally controlled attenuator.

[0011] The adaptive adjustment unit is connected to the control module.

[0012] The fundamental frequency compensation circuit acquires the output signal of the adjustable gain preamplifier via a directional coupler and generates a compensation signal that is in phase and frequency with the main signal. This compensation signal is then injected into the input of the microstrip circuit of the power divider to offset the fundamental frequency power loss caused by the harmonic suppression in the preamplifier stage. The harmonic notch circuit generates a reverse harmonic suppression signal based on the harmonic intensity detected by the feedback detection module. After being adjusted by a digitally controlled attenuator, this signal is injected into the input of the dual-channel power combiner to offset the residual harmonics introduced by the final stage power amplifier. This invention effectively improves the fundamental frequency signal power stability and the final stage harmonic suppression efficiency through the synergistic effect of fundamental frequency compensation and harmonic notch filtering.

[0013] Furthermore, the pre-suppressed harmonic filter is a bandpass filter with a passband frequency range of 5.2~5.8GHz and a stopband attenuation greater than 40dBc.

[0014] Furthermore, the interstage dynamic harmonic suppression module includes an adjustable bandstop filter, which can dynamically adjust the center frequency under the control of the control module.

[0015] Furthermore, the adjustable gain preamplifier has a gain adjustment range of 10~30dB and an adjustment step accuracy of ±0.5dB.

[0016] Furthermore, both the dual power divider microstrip circuit and the dual power combiner microstrip circuit are Wilkinson structures.

[0017] Furthermore, the feedback detection module includes a third harmonic bandpass filter and a detector diode. The output terminal of the third harmonic bandpass filter is connected to the input terminal of the detector diode. The third harmonic bandpass filter extracts the third harmonic component from the synthesized output signal, and then converts it into a DC voltage signal via the detector diode and feeds it back to the control module to achieve accurate third harmonic detection.

[0018] Furthermore, the numerically controlled attenuator is a digital step attenuator with an attenuation range of 0-30dB and a stepping accuracy of ±0.1dB.

[0019] Furthermore, the fundamental frequency compensation circuit includes a variable gain amplifier, the gain adjustment terminal of which is connected to the control module, and the amplitude of the compensation signal is dynamically adjusted under the control of the control module.

[0020] Furthermore, the phase-locked frequency source module is a direct digital frequency synthesizer, and its output signal frequency stability is less than ±1ppm.

[0021] One or more technical solutions provided by this utility model have at least the following technical effects or advantages:

[0022] 1. This utility model solves the problem of reduced harmonic suppression performance of traditional power amplifiers due to temperature drift and device aging by using dynamic harmonic suppression and closed-loop feedback mechanisms, thereby reducing harmonic distortion while ensuring high power output.

[0023] 2. This utility model effectively improves the stability of fundamental signal power and the final harmonic suppression efficiency through the synergistic effect of the fundamental compensation circuit and the harmonic notch circuit. Attached Figure Description

[0024] The accompanying drawings, which are provided to further illustrate the embodiments of the present invention and constitute a part of the present invention, do not constitute a limitation thereof.

[0025] Figure 1 This is one of the connection diagrams of the C-band low harmonic power amplifier in this utility model;

[0026] Figure 2 This is the second connection diagram of the C-band low harmonic power amplifier in this utility model;

[0027] Among them, 20-control module, 21-phase-locked frequency source module, 22-pre-suppressed harmonic filter, 23-adjustable gain preamplifier, 24-interstage dynamic harmonic suppression module, 25-power divider microstrip circuit, 261-first final stage power amplifier, 262-second final stage power amplifier, 27-dual-channel power combiner microstrip circuit, 28-isolator, 29-feedback detector module, 30-adaptive adjustment unit, 301-fundamental compensation circuit, 302-harmonic notch filter circuit, 303-directional coupler, 304-digitally controlled attenuator. Detailed Implementation

[0028] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, where there is no conflict, the embodiments of this utility model and the features thereof can be combined with each other.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0030] Example 1

[0031] Please refer to Figure 1 and Figure 2 This utility model provides a C-band low harmonic power amplifier, including a phase-locked frequency source module 21. The output of the phase-locked frequency source module 21 is sequentially connected to a pre-suppressed harmonic filter 22, an adjustable gain preamplifier 23, an interstage dynamic harmonic suppression module 24, and a dual power divider microstrip circuit 25. The two outputs of the dual power divider microstrip circuit 25 are respectively connected to the inputs of a first final stage power amplifier 261 and a second final stage power amplifier 262. The outputs of the first final stage power amplifier 261 and the second final stage power amplifier 262 are respectively connected to the inputs of a dual-path power combiner microstrip circuit 27. The output of the dual-path power combiner microstrip circuit 27 is connected to an RF output port through an isolator (28) and is also connected to the input of a feedback detection module 29.

[0032] It also includes a control module 20, which is connected to the phase-locked frequency source module 21, the adjustable gain preamplifier 23, the interstage dynamic harmonic suppression module 24, and the feedback detector module 29, respectively.

[0033] This invention does not limit the specific models of the components of the C-band low harmonic power amplifier; those skilled in the art can select them according to actual needs. In this embodiment, the first final stage power amplifier 261 and the second final stage power amplifier 262 are preferably Ampleon's BLF888A LDMOS modules. The control module 20 is based on an STM32H743 microcontroller and has a built-in PID algorithm.

[0034] The amplifier further includes an adaptive adjustment unit 30, which includes a fundamental frequency compensation circuit 301 and a harmonic notch filter circuit 302.

[0035] The input terminal of the fundamental frequency compensation circuit 301 is connected to the output terminal of the adjustable gain preamplifier 23 through a directional coupler 303, and the output terminal of the fundamental frequency compensation circuit 301 is connected to the input terminal of the power divider microstrip circuit 25.

[0036] The input terminal of the harmonic notch circuit 302 is connected to the harmonic intensity detection port of the feedback detection module 29, and the output terminal of the harmonic notch circuit 302 is connected to the input terminal of the dual-channel power combiner microstrip circuit 27 through the digitally controlled attenuator 304.

[0037] The adaptive adjustment unit 30 is connected to the control module 20.

[0038] Among them, the pre-harmonic suppression filter 22 is a bandpass filter with a passband frequency range of 5.2~5.8GHz and a stopband attenuation greater than 40dBc. An LC cavity bandpass filter is preferred to effectively filter out the second harmonic of the phase-locked source.

[0039] The interstage dynamic harmonic suppression module 24 includes an adjustable band-stop filter, preferably an adjustable dielectric resonator band-stop filter, with a center frequency dynamic range of 10-12 GHz. Frequency tracking is achieved by adjusting the varactor diode bias voltage through the PWM signal of the control module 20.

[0040] The adjustable gain preamplifier 23 has a gain adjustment range of 10~30dB and an adjustment step accuracy of ±0.5dB, preferably a Mini Circuits GVA-81+.

[0041] The dual power divider microstrip circuit 25 and the dual power combiner microstrip circuit 27 are both Wilkinson structures.

[0042] The feedback detection module 29 includes a third harmonic bandpass filter and a detector diode, with the output of the third harmonic bandpass filter connected to the input of the detector diode.

[0043] The numerically controlled attenuator 304 is a digital step attenuator with an attenuation range of 0-30dB and a stepping accuracy of ±0.1dB.

[0044] The fundamental frequency compensation circuit 301 includes a variable gain amplifier, the gain adjustment terminal of which is connected to the control module 20. Specifically, the variable gain amplifier can be a Hittite HMC473 amplifier. The compensation signal is injected into the input terminal of the dual power divider microstrip circuit 25 through an RLC matching network. The harmonic notch circuit includes an adjustable band-stop filter and a digitally controlled attenuator. The suppression signal is injected into the input terminal of the dual power combiner microstrip circuit 27 through a λ / 4 microstrip line.

[0045] Among them, the phase-locked frequency source module 21 is a direct digital frequency synthesizer with an output signal frequency stability of less than ±1ppm. It preferably uses the ADF4351 integrated phase-locked loop chip from Analog Devices, with an output frequency range of 5.2-5.8GHz, and is connected to the control module 20 through the SPI interface.

[0046] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0047] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A C-band low harmonic power amplifier, characterized in that, The system includes a phase-locked frequency source module (21), the output of which is sequentially connected to a pre-suppressed harmonic filter (22), an adjustable gain preamplifier (23), an interstage dynamic harmonic suppression module (24), and a dual power divider microstrip circuit (25). The two outputs of the dual power divider microstrip circuit (25) are respectively connected to the inputs of the first final stage power amplifier (261) and the second final stage power amplifier (262). The outputs of the first final stage power amplifier (261) and the second final stage power amplifier (262) are respectively connected to the inputs of a dual-path power combiner microstrip circuit (27). The output of the dual-path power combiner microstrip circuit (27) is connected to the RF output port through an isolator (28) and is also connected to the input of the feedback detector module (29). It also includes a control module (20), which is connected to the phase-locked frequency source module (21), the adjustable gain preamplifier (23), the interstage dynamic harmonic suppression module (24), and the feedback detector module (29), respectively.

2. The C-band low harmonic power amplifier according to claim 1, characterized in that, The amplifier also includes an adaptive adjustment unit (30), which includes a fundamental frequency compensation circuit (301) and a harmonic notch circuit (302). The input terminal of the fundamental wave compensation circuit (301) is connected to the output terminal of the adjustable gain preamplifier (23) through a directional coupler (303), and the output terminal of the fundamental wave compensation circuit (301) is connected to the input terminal of the dual power divider microstrip circuit (25). The input terminal of the harmonic notch circuit (302) is connected to the harmonic intensity detection port of the feedback detection module (29), and the output terminal of the harmonic notch circuit (302) is connected to the input terminal of the dual-channel power combiner microstrip circuit (27) through the digitally controlled attenuator (304). The adaptive adjustment unit (30) is connected to the control module (20).

3. The C-band low harmonic power amplifier according to claim 1, characterized in that, The pre-suppressed harmonic filter (22) is a bandpass filter with a passband frequency range of 5.2~5.8GHz and a stopband attenuation greater than 40dBc.

4. The C-band low harmonic power amplifier according to claim 1, characterized in that, The interstage dynamic harmonic suppression module (24) includes an adjustable bandstop filter.

5. The C-band low harmonic power amplifier according to claim 1, characterized in that, The adjustable gain preamplifier (23) has a gain adjustment range of 10~30dB and an adjustment step accuracy of ±0.5dB.

6. The C-band low harmonic power amplifier according to claim 1, characterized in that, Both the dual power divider microstrip circuit (25) and the dual power combiner microstrip circuit (27) are Wilkinson structures.

7. The C-band low harmonic power amplifier according to claim 1, characterized in that, The feedback detection module (29) includes a third harmonic bandpass filter and a detector diode, with the output terminal of the third harmonic bandpass filter connected to the input terminal of the detector diode.

8. The C-band low harmonic power amplifier according to claim 2, characterized in that, The numerically controlled attenuator (304) is a digital step attenuator with an attenuation range of 0-30dB and a stepping accuracy of ±0.1dB.

9. The C-band low harmonic power amplifier according to claim 2, characterized in that, The fundamental frequency compensation circuit (301) includes a variable gain amplifier, the gain adjustment terminal of which is connected to the control module (20).

10. The C-band low harmonic power amplifier according to claim 1, characterized in that, The phase-locked frequency source module (21) is a direct digital frequency synthesizer, and its output signal frequency stability is less than ±1ppm.

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