A method and system for improving the second and third harmonic index of an output port

Abstract

The application discloses a method and system for improving output port second and third harmonic indexes, and belongs to the field of electromagnetic field and microwave technology.The method comprises the following steps: S1, amplifying an input first excitation signal through a small signal amplifier, then extracting second and third harmonic signals, and outputting a second excitation signal; S2, pre-processing the output second and third harmonic signals; S3, outputting a wideband synthesized double-tone signal by the pre-processed second and third harmonic signals; S4, outputting the pre-processed second excitation signal after pre-processing, and feeding the wideband synthesized double-tone signal into the second excitation signal; S5, obtaining a third excitation signal by 180-degree phase cancellation of the second and third harmonics of the pre-processed second excitation signal through the double-tone signal, and outputting the third excitation signal to an antenna.Compared with the traditional method of increasing filters, the transmission power signal is increased by 0.4 dB; meanwhile, the efficiency index of the transmitter is improved, and the efficiency and reliability of the transmitter are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electromagnetic field and microwave technology, and particularly relates to a method and system for improving second and third harmonic indexes of an output port. BACKGROUND

[0002] Currently, the transmitter in the technical field of airborne integrated avionics equipment is a multi-mode transmitter, and the functions and signal formats thereof generally include air traffic control, ADS-B, DME, TACAN, data link, etc., wherein the DME, TACAN and data link modes operate in a wide band, generally 960-1224 MHz. The current multi-mode transmitter generally adopts a GaN power amplifier tube to realize power amplification function, and the port power index is generally in the order of magnitude of 1000W-2000W. The current multi-mode transmitter generally adopts an output port plus filter method to improve the second and third harmonic indexes of the output power. The current multi-mode transmitter generally adopts an output port plus filter method to improve the second and third harmonic indexes of the output power, and the cost is to increase the insertion loss at the rear end of the output amplifier, generally a low-pass filter increases the loss of 0.7 dB, thereby the second and third harmonic indexes of the port can be improved by more than 25 dB. SUMMARY

[0003] The present application aims at overcoming the deficiencies of the prior art, and provides a method and system for improving the second and third harmonic indexes of an output port.

[0004] The purpose of the present application is achieved by the following technical solutions.

[0005] In a first aspect, the present application discloses a method for improving the second and third harmonic indexes of an output port, comprising the following steps:

[0006] S1, input a first excitation signal, amplify the first excitation signal through a small signal amplifier, extract second and third harmonic signals through a first second and third harmonic coupler, and then output three signals, wherein a first output second excitation signal, a second output second harmonic signal, and a third output third harmonic signal;

[0007] S2, pre-process the second harmonic signal output by the second output and the third harmonic signal output by the third output;

[0008] S3, wideband synthesis of the pre-processed second and third harmonic signals, and output a dual-tone signal;

[0009] S4, pre-process the second excitation signal output by the first output, and output to a second second and third harmonic coupler and a receiver respectively, and feed the wideband synthesized dual-tone signal into the second second and third harmonic coupler;

[0010] S5, the second excitation signal after preprocessing is obtained by 180° phase cancellation of the second and third harmonic of the signal, and the third excitation signal is output to the antenna.

[0011] Based on the first aspect, the preprocessing in step S2 includes amplification, filtering and phase shift, the third harmonic signal is amplified by a third harmonic amplifier, the amplified third harmonic signal is filtered by a third harmonic band-pass filter, and then the filtered third harmonic signal is phase-shifted by a third harmonic phase shifter; the second harmonic signal is amplified by a second harmonic amplifier, the amplified second harmonic signal is filtered by a second harmonic band-pass filter, and then the filtered second harmonic signal is phase-shifted by a second harmonic phase shifter; wherein the second harmonic phase shifter and the third harmonic phase shifter use a preset range of phase shift parameters for phase shift.

[0012] Based on the first aspect, the second harmonic phase shifter and the third harmonic phase shifter are controlled by a digital processing board.

[0013] Based on the first aspect, step S3 specifically includes: combining the preprocessed second and third harmonic signals into one through a duplexer to output a two-tone signal, and the two-tone signal includes two frequency components of radio frequency signals.

[0014] Based on the first aspect, the preprocessing of the second excitation signal output in step S4 includes: sequentially amplifying the second excitation signal through a drive amplifier, outputting the amplified second excitation signal through an isolator, then amplifying the power of the second excitation signal to a target power through a final power amplifier, then realizing directional transmission of the second excitation signal through a circulator, outputting to a receiver and a second two-three harmonic coupler, and feeding the wideband synthesized two-tone signal into the second two-three harmonic coupler.

[0015] Based on the first aspect, when 180° phase cancellation is performed in step S5, the separated harmonic energy is absorbed and converted by an absorption load connected to the second two-three harmonic coupler.

[0016] Secondly, the present application discloses a system for improving the two-three harmonic indicators of the output port, which is used for the method for improving the two-three harmonic indicators of the output port in any one of the above-mentioned first aspect, comprising: a main amplification link part circuit, a phase shift conditioning circuit and a digital processing board, the phase shift conditioning circuit is connected to the main amplification link part circuit and the digital processing board, and is used for preprocessing the second harmonic signal output from the second path and the third harmonic signal output from the third path, then performing wideband synthesis, and outputting the two-tone signal to the main amplification link part circuit.

[0017] The main amplification link part circuit is used for amplifying the input first excitation signal to a target system power through a small signal amplifier, and then outputting a second excitation signal through a first 2-3 harmonic coupler; after the second excitation signal is preprocessed, the second excitation signal is output to an antenna through a second 2-3 harmonic coupler.

[0018] The digital processing board is used for storing the preprocessed second and third harmonic signals, reading the phase shift information of the second and third harmonics, and controlling the phase shifters of the second and third harmonics.

[0019] Based on the second aspect, the main amplification link part circuit comprises a small signal amplifier, a first 2-3 harmonic coupler, a driving amplifier, an isolator, a final power amplifier, a circulator and a second 2-3 harmonic coupler; the output end of the small signal amplifier is connected to the input end of the first 2-3 harmonic coupler; the output end of the first 2-3 harmonic coupler is connected to the input end of the driving amplifier; the output end of the driving amplifier is connected to the input end of the isolator; the output end of the isolator is connected to the final power amplifier; the output end of the final power amplifier is connected to the input end of the circulator; the output end of the circulator is connected to the receiver and the second 2-3 harmonic coupler respectively; and the output end of the second 2-3 harmonic coupler is connected to the antenna and the circulator respectively.

[0020] Based on the second aspect, the phase shift conditioning circuit comprises a third harmonic amplifier, a third harmonic bandpass filter, a third harmonic phase shifter, a second harmonic amplifier, a second harmonic bandpass filter, a second harmonic phase shifter, a 2-3 harmonic broadband combiner and an absorbing load; the input ends of the third harmonic amplifier and the second harmonic amplifier are connected to the output end of the first 2-3 harmonic coupler respectively; the output end of the third harmonic amplifier is connected to the input end of the third harmonic bandpass filter; the output end of the third harmonic bandpass filter is connected to the input end of the third harmonic phase shifter; the output end of the second harmonic amplifier is connected to the input end of the second harmonic bandpass filter; the output end of the second harmonic bandpass filter is connected to the input end of the second harmonic phase shifter; the output ends of the second harmonic phase shifter and the third harmonic phase shifter are connected to the 2-3 harmonic broadband combiner; and the absorbing load is connected to the second 2-3 harmonic coupler.

[0021] Based on the second aspect, the digital processing board comprises an embedded processor; the output end of the embedded processor is connected to the input ends of the second harmonic phase shifter and the third harmonic phase shifter; and the embedded processor comprises an FPGA, a temperature sensor, a FLASH and an isolation driver.

[0022] The present application has the following beneficial effects:

[0023] 1) Compared with the traditional method of increasing the filter, the present application increases the transmission power signal by 0.4 dB; meanwhile, the efficiency index of the transmitter is improved, and the efficiency and reliability of the transmitter are improved;

[0024] 2) The second and third harmonic power is reduced by about 25dB, so as to avoid using a filter with high loss to improve the second and third harmonic index of the output port. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A step schematic diagram of a method for improving the second and third harmonic index of the output port according to an embodiment of the present application is shown in the figure.

[0026] Figure 2 A schematic diagram of a system for improving the second and third harmonic index of the output port according to an embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0027] The technical solutions of the present application will be described clearly and completely below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0028] The present application discloses a method for improving the second and third harmonic index of the output port. The method realizes that the transmitter couples out the second and third harmonic through the input small signal, then synthesizes a conditioning signal through the phase shifter, and feeds back the second and third harmonic coupling signal with 180° phase difference to the power amplifier output port, so that the fundamental signal of the output main path is not affected, and the second and third harmonic index is reduced by about 25dB, thereby improving the second and third harmonic index. The advantage of the method is that a low-pass filter is not designed at the output port, so that the loss of the transmission power signal is increased by 0.7dB, and a second and third harmonic coupler is designed instead, so that the loss of the transmission power signal is increased by only 0.3dB. The efficiency and reliability of the transmitter can be greatly improved, and the method has high economic value. A step schematic diagram of the method is shown in the figure. Figure 1 The method comprises the following steps:

[0029] S1, input a first excitation signal, amplify the first excitation signal through a small signal amplifier, extract the second and third harmonic signals through a first second and third harmonic coupler, and then output three signals, wherein a second excitation signal is output as a first output signal, a second harmonic signal is output as a second output signal, and a third harmonic signal is output as a third output signal;

[0030] S2, pre-process the second harmonic signal output by the second output and the third harmonic signal output by the third output;

[0031] S3, wideband synthesis the pre-processed second and third harmonic signals to output a dual-tone signal;

[0032] S4, the second excitation signal outputted from the first path is preprocessed and outputted to the second 2-3 harmonic coupler and the receiver respectively, and the double tone signal synthesized by the wide band is fed into the second 2-3 harmonic coupler;

[0033] S5, the second and third harmonics of the preprocessed second excitation signal are phase cancelled by 180° through the double tone signal, and the third excitation signal is obtained and outputted to the antenna.

[0034] Exemplarily, the first excitation signal is inputted in step S1, the first excitation signal is amplified by a small signal amplifier, the second and third harmonics are extracted from the first 2-3 harmonic coupler, and then three signals are outputted, wherein the second excitation signal is outputted from the first path, the second harmonic signal is outputted from the second path, and the third harmonic signal is outputted from the third path; when the fundamental frequency of the first excitation signal is 1GHz, the second harmonic of 2GHz and the third harmonic of 3GHz can be extracted, and the power is about 0dBm for the second harmonic of 2GHz and about -10dBm for the third harmonic of 3GHz.

[0035] Exemplarily, the preprocessing in step S2 includes amplification, filtering and phase shifting, the third harmonic signal is amplified by a third harmonic amplifier, the amplified third harmonic signal is filtered by a third harmonic band-pass filter, and then the filtered third harmonic signal is phase shifted by a third harmonic phase shifter; the second harmonic signal is amplified by a second harmonic amplifier, the amplified second harmonic signal is filtered by a second harmonic band-pass filter, and then the filtered second harmonic signal is phase shifted by a second harmonic phase shifter; wherein the second harmonic phase shifter and the third harmonic phase shifter are phase shifted by using a phase shifting parameter in a preset range, the preset range is a range set in advance according to the working environment, and is not limited to a specific range, and in the embodiment, the phase shifting parameter is obtained by circuit test to obtain a specific range. The power of the second harmonic of 2GHz is about 22dBm, and the phase shifting code is 111000; and the phase shifting code can be adjusted or fine-tuned by the harmonic suppression degree measured by the final port. The power of the third harmonic of 3GHz is about 12dBm, and the phase shifting code is 000111; and the phase shifting code can be adjusted or fine-tuned by the harmonic suppression degree measured by the final port. The second harmonic phase shifter and the third harmonic phase shifter are controlled by a digital processing board.

[0036] Exemplarily, the step S3 specifically comprises: combining the pre-processed second and third harmonic signals into one through a duplexer to output a two-tone signal, the two-tone signal comprising two frequency components of radio frequency signals. At this time, a duplexer with 2GHz and 3GHz as input ports and 2-3GHz as a wideband output port is used to combine two signals with frequencies of 2GHz and 3GHz into a radio frequency wideband combined signal containing two frequency components; the combined signal is a two-tone signal, wherein the first tone is a second harmonic of 2GHz with a power of about 19dBm, and the second tone is a third harmonic of 3GHz with a power of about 9dBm.

[0037] Exemplarily, the pre-processing of the first output second excitation signal in the step S4 comprises: sequentially amplifying the second excitation signal through a driver amplifier, outputting the amplified second excitation signal through an isolator, then amplifying the power of the second excitation signal to a target power through a final power amplifier, and then realizing directional transmission of the second excitation signal through a circulator, one-way output to a receiver and one-way output to a second two-three harmonic coupler, and feeding the wideband combined two-tone signal into the second two-three harmonic coupler.

[0038] Exemplarily, when the 180° phase cancellation is performed in the step S5, the separated harmonic energy is absorbed and converted by an absorption load connected to the second two-three harmonic coupler. From the output port test, the fundamental wave, second harmonic and third harmonic powers when not fed in through wideband synthesis are as follows: the fundamental wave power of 1GHz is about 60dBm, the second harmonic power of 2GHz is about 20dBm, and the third harmonic power of 3GHz is about 10dBm; from the output port test, after phase shifting through debugging, the fundamental wave, second harmonic and third harmonic powers when fed in through wideband synthesis are as follows: the fundamental wave power of 1GHz is about 60dBm, the second harmonic power of 2GHz is about -5dBm, and the third harmonic power of 3GHz is about -25dBm; the second and third harmonic powers are reduced by about 25dB, achieving the purpose of improving the output port second and third harmonic indicators. Compared with the traditional method of increasing filters, the transmission power signal is increased by 0.4dB compared with the traditional method. At the same time, the efficiency index of the transmitter is improved.

[0039] In a second aspect, the present application discloses a system for improving the output port second and third harmonic indicators, the schematic diagram of which is as shown in Figure 2As shown, for the above-mentioned method for improving the output port second and third harmonic index, including: main amplification link part circuit, phase shift conditioning circuit and digital processing board. The phase shift conditioning circuit connects the main amplification link part circuit and the digital processing board, including: third harmonic amplifier, third harmonic band pass filter, third harmonic phase shifter, second harmonic amplifier, second harmonic band pass filter, second harmonic phase shifter, second and third harmonic wideband power combiner and absorbing load, the input end of the third harmonic amplifier and the second harmonic amplifier is connected with the output end of the first second and third harmonic coupler respectively, the output end of the third harmonic amplifier is connected with the input end of the third harmonic band pass filter, the output end of the third harmonic band pass filter is connected with the input end of the third harmonic phase shifter, the output end of the second harmonic amplifier is connected with the input end of the second harmonic band pass filter, the output end of the second harmonic band pass filter is connected with the input end of the second harmonic phase shifter, the output end of the second harmonic phase shifter and the third harmonic phase shifter is connected with the second and third harmonic wideband power combiner, and the absorbing load is connected with the second second and third harmonic coupler.

[0040] For the second output of the second harmonic signal and the third output of the third harmonic signal, the second harmonic signal and the third harmonic signal are preprocessed, and then wideband synthesis is carried out, and the double tone signal is output to the main amplification link part circuit; the second harmonic and the third harmonic coupled out from the first second and third harmonic coupler of the small signal are formed into the second and third harmonic signals with relatively single spectrum through the second harmonic amplifier, the band pass filter, the third harmonic amplifier and the band pass filter, and then through the corresponding phase shifter (the phase shifter is controlled by the digital processing board), and then through the wideband synthesizer to combine the two signals into the required cancellation signal, and then fed into the second second and third harmonic coupler at the rear end of the final amplifier, to form the second and third harmonic cancellation signal of the main signal.

[0041] Specifically, the main amplification link part circuit comprises a small signal amplifier, a first 2-3 harmonic coupler, a driver amplifier, an isolator, a final power amplifier, a circulator and a second 2-3 harmonic coupler, the output of the small signal amplifier is connected to the input of the first 2-3 harmonic coupler, the output of the first 2-3 harmonic coupler is connected to the input of the driver amplifier, the output of the driver amplifier is connected to the input of the isolator, the output of the isolator is connected to the final power amplifier, the output of the final power amplifier is connected to the input of the circulator, the output of the circulator is connected to the receiver and the second 2-3 harmonic coupler respectively, and the output of the second 2-3 harmonic coupler is connected to the antenna and the circulator respectively. The input first excitation signal is amplified to the target system power through the small signal amplifier, and then output second excitation signal through the first 2-3 harmonic coupler, and then output to the antenna through the second 2-3 harmonic coupler after the second excitation signal is preprocessed; the input first excitation signal is amplified to about 25 dBm through the small signal amplifier, and then amplified to the order of 100 W through the first 2-3 harmonic coupler and the driver amplifier, and then input to the final power amplifier through the isolator, and then the power is amplified to the order of 2500 W through the final power amplifier, and then the signal is output to the antenna through the circulator and the second 2-3 harmonic coupler, and at the same time, the signal is also output to the receiver through the circulator.

[0042] Specifically, the digital processing board comprises an embedded processor, generally an FPGA, and some conventional hardware such as a temperature sensor, a FLASH, an isolation driver and the like; the second and third harmonic phase shift information obtained through debugging can be stored in the FLASH, and the second and third harmonic phase shift information can be read through the FLASH and the phase shifters of the second and third harmonics can be controlled through the isolation driver. The output of the embedded processor is connected to the input of the second harmonic phase shifter and the third harmonic phase shifter.

[0043] Exemplarily, compared with the conventional method of increasing the filter, the transmission power signal is increased by 0.4 dB compared with the conventional method. Meanwhile, the efficiency index of the transmitter is improved. Meanwhile, the second and third harmonic powers are reduced by about 25 dB, so as to avoid using a large-loss filter to improve the second and third harmonic indexes of the output port. The present application can also regulate the fourth harmonic and even higher harmonics through coupling, so as to improve the higher harmonics.

[0044] The above only describes the preferred embodiments of the present application, and it should be understood that the present application is not limited to the forms disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concepts described herein through the above teachings or related art or knowledge. Any modification and change made by those skilled in the art without departing from the spirit and scope of the present application shall be within the protection scope of the appended claims of the present application.

Claims

1. A method for improving the second and third harmonic performance of an output port, characterized in that, Includes the following steps: S1. Input a first excitation signal. After the first excitation signal is amplified by a small signal amplifier, the second and third harmonic signals are extracted by the first second and third harmonic couplers. Then, three signals are output, of which the first output is the second excitation signal, the second output is the second harmonic signal, and the third output is the third harmonic signal. S2. Preprocess the second harmonic signal output from the second channel and the third harmonic signal output from the third channel; S3. Broadband synthesis of the preprocessed second and third harmonic signals to output a two-tone signal; S4. After preprocessing the second excitation signal output from the first channel, it is output to the second second and third harmonic couplers and the receiver respectively, and the broadband synthesized two-tone signal is fed into the second second and third harmonic couplers. S5. The second and third harmonics of the preprocessed second excitation signal are phase-cancelled by 180° using a dual-tone signal to obtain the third excitation signal, and the third excitation signal is output to the antenna. During the 180° phase cancellation in step S5, the separated harmonic energy is absorbed and converted by the absorption load connected to the second and third harmonic couplers.

2. The method for improving the second and third harmonic performance of an output port according to claim 1, characterized in that: The preprocessing described in step S2 includes amplification, filtering, and phase shifting. The third harmonic signal is amplified by a third harmonic amplifier, filtered by a third harmonic bandpass filter, and then phase-shifted by a third harmonic phase shifter. The second harmonic signal is amplified by a second harmonic amplifier, filtered by a second harmonic bandpass filter, and then phase-shifted by a second harmonic phase shifter. The second and third harmonic phase shifters use phase shifting parameters within a preset range for phase shifting.

3. The method for improving the second and third harmonic performance of the output port according to claim 2, characterized in that: The second and third harmonic phase shifters are controlled by a digital processing board.

4. The method for improving the second and third harmonic performance of the output port according to claim 3, characterized in that, Step S3 specifically includes: combining the preprocessed second and third harmonic signals into one channel using a duplexer, and outputting a two-tone signal, wherein the two-tone signal includes radio frequency signals with two frequency components.

5. The method for improving the second and third harmonic performance of an output port according to claim 1, characterized in that, The preprocessing of the second excitation signal output from the first channel in step S4 includes: amplifying the second excitation signal sequentially through a driver amplifier, outputting the amplified second excitation signal through an isolator, then amplifying the power of the second excitation signal to the target power through a final stage power amplifier, and then realizing the directional transmission of the second excitation signal through a circulator, with one output to the receiver and the other output to the second and third harmonic couplers, feeding the broadband synthesized two-tone signal into the second and third harmonic couplers.

6. A system for improving the second and third harmonic performance of an output port, used in accordance with the method for improving the second and third harmonic performance of an output port as described in any one of claims 1-5, characterized in that, include: The circuit includes a main amplification link section, a phase-shifting conditioning circuit, and a digital processing board. The phase-shifting conditioning circuit is connected to the main amplification link section and the digital processing board. It is used to preprocess the second harmonic signal output from the second channel and the third harmonic signal output from the third channel, and then perform broadband synthesis to output a two-tone signal to the main amplification link section. The main amplification link circuit is used to amplify the input first excitation signal to the target system power through a small signal amplifier, and then output the second excitation signal through the first, second and third harmonic coupling. After preprocessing the second excitation signal, it is output to the antenna through the second, second and third harmonic coupler. The digital processing board is used to store the second and third harmonic signals after debugging and preprocessing, and to read the phase shift information of the second and third harmonics and control the phase shifters of the second and third harmonics.

7. A system for improving the second and third harmonic performance of an output port according to claim 6, characterized in that, The main amplification link circuit includes: a small-signal amplifier, a first, second, and third harmonic coupler, a driver amplifier, an isolator, a final-stage power amplifier, a circulator, and a second, second, and third harmonic coupler. The output of the small-signal amplifier is connected to the input of the first, second, and third harmonic coupler. The output of the first, second, and third harmonic coupler is connected to the input of the driver amplifier. The output of the driver amplifier is connected to the input of the isolator. The output of the isolator is connected to the final-stage power amplifier. The output of the final-stage power amplifier is connected to the input of the circulator. The output of the circulator is connected to the receiver and the second, second, and third harmonic coupler, respectively. The output of the second, second, and third harmonic coupler is connected to the antenna and the circulator, respectively.

8. A system for improving the second and third harmonic performance of an output port according to claim 6, characterized in that, The phase-shifting conditioning circuit includes: a third harmonic amplifier, a third harmonic bandpass filter, a third harmonic phase shifter, a second harmonic amplifier, a second harmonic bandpass filter, a second harmonic phase shifter, a second and third harmonic broadband power coupler, and an absorption load. The input terminals of the third harmonic amplifier and the second harmonic amplifier are respectively connected to the output terminals of the first second and third harmonic coupler. The output terminal of the third harmonic amplifier is connected to the input terminal of the third harmonic bandpass filter, and the output terminal of the third harmonic bandpass filter is connected to the input terminal of the third harmonic phase shifter. The output terminal of the second harmonic amplifier is connected to the input terminal of the second harmonic bandpass filter, and the output terminal of the second harmonic bandpass filter is connected to the input terminal of the second harmonic phase shifter. The output terminals of the second and third harmonic phase shifters are connected to the second and third harmonic broadband power coupler. The absorption load is connected to the second second and third harmonic coupler.

9. A system for improving the second and third harmonic performance of an output port according to claim 8, characterized in that, The digital processing board includes an embedded processor, the output of which is connected to the inputs of the second harmonic phase shifter and the third harmonic phase shifter. The embedded processor includes an FPGA, a temperature sensor, FLASH memory, and an isolation driver.

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