A jammer polarization diversity performance test system and method

Abstract

The present invention relates to the technical field of jammer testing, and discloses a jammer polarization diversity performance testing system and method. The system adopted by the method includes: a signal transmitting and receiving system, a jammer and a control system. The signal transmitting and receiving system includes: a signal transmitting system and a signal receiving system. The signal transmitting system includes a signal transmitting antenna and a signal transmitting amplification processing circuit. The signal transmitting antenna is connected to the output end of the control system through a signal radio frequency cable and a signal transmitting amplification processing circuit. The signal receiving system is composed of a signal receiving antenna connected to the receiving end of the control system through a signal radio frequency cable and a signal receiving amplification processing circuit. The present invention can judge the polarization diversity performance of the jammer. The problem that the polarization diversity of the jammer is difficult to test is solved, and the automatic switching of the transmitting antenna and the receiving antenna is realized, and the automatic selection of various combination modes of the polarization of the transmitting antenna is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of radar jammer performance testing, and in particular to a jammer polarization diversity performance testing system and method. The system and method are applied to jammer performance testing and can efficiently perform polarization diversity performance testing, which is convenient, fast and accurate. Background Art

[0002] Diversity technology mainly includes the following five forms: time diversity, frequency diversity, space diversity, polarization diversity and pattern diversity, etc. The first two belong to the category of coding and signal processing, and the latter three belong to the category of antenna diversity. Polarization diversity technology is a new technology developed based on polarization radar with diversified antennas. Target identification and anti-interference through polarization diversity and polarization adaptive technology are one of the important development directions of radar technology in recent years. Usually, the polarization diversity system of jammers is divided into time-division system and simultaneous system. At present, the polarization diversity system is widely used in jamming technology to improve the jamming effect on enemy weapons and equipment, but there is no performance-related test method for polarization diversity jamming effect in China. The present invention is used to test the polarization diversity jamming effect of jammers. Summary of the invention

[0003] In order to test the polarization diversity performance of a jammer, the present invention provides a jammer polarization diversity performance testing system and method, so as to test the polarization diversity performance of the jammer more conveniently, quickly, accurately and efficiently. At the same time, a radio frequency switching circuit is adopted to facilitate the switching of the transmitting and receiving antennas, simplify the operation and save time.

[0004] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows:

[0005] A jammer polarization diversity performance test system comprises: a signal transmitting and receiving system, a jammer and a control system, wherein the signal transmitting and receiving system comprises: a signal transmitting system and a signal receiving system;

[0006] The signal transmission system includes a signal transmission antenna and a signal transmission amplification processing circuit; the signal transmission antenna is connected to the output end of the control system through a signal radio frequency cable and a signal transmission amplification processing circuit;

[0007] The signal receiving system comprises a signal receiving antenna and a signal receiving processing circuit; the signal receiving antenna is connected to the receiving end of the control system through a signal radio frequency cable and a signal receiving amplification processing circuit;

[0008] The antenna array composed of the signal transmitting antenna and the signal receiving antenna is arranged on the lifting platform through the antenna rack, the jammer is arranged on the turntable through the equipment rack, and the lifting platform, the jammer and the turntable are respectively connected to the control system through cables.

[0009] A jammer polarization diversity performance test system, wherein the antenna array corresponds to an antenna rack, the antenna array is an antenna group of 2 rows and 4 columns, the antenna array is selected as a wideband antenna, the antenna rack is a rectangular plane antenna rack, the antenna rack is evenly spaced with 2 rows and 4 columns of antennas, the antenna rack has an axis perpendicular to the plane of the antenna rack, and the antenna axis is parallel to the antenna rack axis; wherein the antenna rack is sequentially configured with signal transmitting antennas 1-4 in the upper row, and the antenna rack is sequentially configured with signal receiving antennas 1' to 4' in the lower row, and the signal transmitting antennas 1 to 4 and the signal receiving antennas 1' to 4' are horizontally polarized, vertically polarized, left-hand circularly polarized, and right-hand circularly polarized antennas respectively;

[0010] A jammer antenna is arranged in the main lobe of the transceiver antenna; and wave absorbing materials are arranged between the transceiver antennas to reduce the distance between the transceiver antennas and the mutual coupling.

[0011] A jammer polarization diversity performance test system, the signal transmission amplification processing circuit includes a switch matrix switching circuit and a transmission amplification circuit for antenna transmission, the switch matrix switching circuit input end is connected to the transmission amplification circuit, and the switch matrix switching circuit output end is connected to the transmission antenna 1 to 4;

[0012] The switch matrix switching circuit includes: a four-to-one radio frequency switch SP4T and a two-to-one radio frequency switch SP2T switch;

[0013] The transmitting amplifier circuit comprises: a signal source 1, a signal source 2, a power amplifier 1, and a power amplifier 2. The signal source 1 is connected to the power amplifier 1, and the signal source 2 is connected to the power amplifier 2. The power amplifier 1 and the power amplifier 2 are respectively connected to the first and second four-to-one radio frequency switches SP4T; used to provide two output signals, respectively connected to two SP4Ts to provide two radio frequency signals for the transmitting antenna;

[0014] The first output end of the first four-choice RF switch SP4T is connected to the first transmitting antenna through an RF cable; the second output end is connected to the second transmitting antenna through an RF cable and a two-choice RF switch SP2T; the third output end is connected to the third transmitting antenna through an RF cable and a two-choice RF switch SP2T; the fourth output end is connected to the fourth transmitting antenna through an RF cable and a two-choice RF switch SP2T;

[0015] The first output end of the second four-choice RF switch SP4T is connected to the second transmitting antenna through the RF cable and the two-choice RF switch SP2T; the second output end is connected to the third transmitting antenna through the RF cable and the two-choice RF switch SP2T; the third output end is connected to the fourth transmitting antenna through the RF cable and the two-choice RF switch SP2T; the fourth output end is connected to the load through the RF cable;

[0016] (1) It is able to select one signal. Signal source 1 transmits a signal. The first four-to-one switch is selected. The four antennas are selected one by one through the switch matrix. There are four modes in total to test the performance of the time-division multi-function jammer.

[0017] Select mode 1: select antenna 1, which means the transmitting antenna is horizontally polarized;

[0018] Select mode 2: select antenna 2, which means the transmitting antenna is vertically polarized;

[0019] Select mode 3: select antenna 3, which means the transmitting antenna is left-hand polarized;

[0020] Selection mode 4: select antenna 4, which means the transmitting antenna is right-hand polarization;

[0021] (2) It can select two signals at the same time. Signal source 1 and signal source 2 transmit signals at the same time. The switch matrix switching circuit can select two of the four antennas, including 6 selection modes, to achieve the performance test of the simultaneous group-controlled jammer.

[0022] Selection mode 1: The selected antenna pair is antenna 1 and antenna 2, and the transmitting antenna mode is horizontal and vertical polarization;

[0023] Selection mode 2: The selected antenna pair is antenna 1 and 3, and the transmitting antenna pattern is horizontal and left-hand circular polarization;

[0024] Selection mode 3: antenna pairs 1 and 4 are selected, and the transmitting antenna pattern is horizontal and right-hand circular polarization;

[0025] Selection mode 4: antenna pairs 2 and 3 are selected, and the transmitting antenna pattern is vertical and left-hand circular polarization;

[0026] Selection mode 5: Antenna pairs 2 and 4 are selected, and the transmitting antenna pattern is vertical and right-hand circular polarization;

[0027] Selection mode six: For the selected antenna pairs 3 and 4, the transmitting antenna patterns are left-hand and right-hand circular polarization.

[0028] A jammer polarization diversity performance test system, wherein the signal receiving amplification processing circuit comprises a switch matrix switching circuit for antenna reception and a receiving amplification circuit;

[0029] The output end of the receiving antenna switch matrix switching circuit is connected to the receiving amplification circuit, and the input end of the switch matrix switching circuit is connected to the transmitting antennas 1'~4'. The switch matrix switching circuit is used to select the four receiving antennas one by one; the input end of the four-to-one radio frequency switch is connected to the spectrum analyzer through a low-noise power amplifier; the spectrum analyzer is connected to SP4T, and performs signal analysis on the received 1', 2', 3', and 4' signals respectively through the receiving antenna; the signal source and the spectrum analyzer realize control signal transmission and data reception, processing and storage through an industrial computer.

[0030] A test method for a jammer polarization diversity performance test system, the steps of which are as follows:

[0031] 1. Test technical requirements:

[0032] (1) In this test, the power of each input signal reaching the antenna interface of the jammer must be greater than the sensitivity value of the jammer by 3dB (except for specific requirements), so that the jammer can work normally;

[0033] (2) The test is conducted in a microwave darkroom. The test site should meet the far-field conditions and have no multipath reflection. The central axis of the standard gain antenna group used by the RF signal source to transmit the signal is aligned;

[0034] The distance R between the jammer antenna and the transmitting antenna should meet the requirements of (1):

[0035] R≥2(D+d) 2 / λ (1)

[0036] Where: D is the aperture of the antenna under test, the maximum size of the equivalent aperture, m; d is the aperture of the source antenna, the equivalent aperture size, m; λ is the shortest operating wavelength, m; R is the distance between the geometric center of the source antenna and the antenna under test, m.

[0037] (3) The RF signal source used for testing has output power, power indication that meets accuracy requirements, and output frequency indication, and has internal pulse modulation capability and pulse parameter indication that meets accuracy requirements;

[0038] (4) Selection of test frequency points: within the interference frequency range, uniform distribution according to the frequency band or uniform distribution according to the logarithm of the frequency, arbitrarily select n, to be determined, frequency points, including upper and lower limit frequency points;

[0039] 2. Test steps

[0040] 1. Build the jammer polarization diversity test system, connect each instrument and equipment in turn, connect the entire test link, raise the lifting platform, and align the jammer with the central axis of the antenna array;

[0041] This test system needs to be carried out in a microwave darkroom. The transmitting and receiving antennas are installed on the lifting platform, and the jammer is placed on the jammer rack of the turntable. Through optical alignment, the antenna of the jammer can be aligned with the center of the antenna array.

[0042] 2. Set the RF signal source to internal pulse modulation mode, the modulation pulse width is 1μs, the pulse repetition frequency is 1kHz, and the output signal frequency is set to the first selected frequency f 1 , the output signal corresponding to each signal in the test must be greater than the sensitivity value; the spectrum analyzer selects the frequency value corresponding to the signal source (for time-division and group-division multi-signal jammer testing, only signal source 1 needs to transmit the signal, and for simultaneous multi-signal jammer testing, the two signal sources are set in the same way);

[0043] 3. Start the jammer under test first, control it to be in normal working state, and set the RF switch of the signal transmitter to mode 1 (the corresponding modes are used for time-division and division-collection system or simultaneous division-collection system);

[0044] 4. Select antennas 1, 2, 3, and 4 (corresponding to horizontal, vertical, left-hand, and right-hand respectively) on the RF switch connected to the signal receiving end, and record the signal power values ​​corresponding to the spectrum analyzer at the frequency points respectively.

[0045] 5. Set the RF switch of the signal transmitter to the remaining modes in turn (for the time-division and collective jammer, select the remaining 3 modes respectively, and for the simultaneous division and collective jammer, select the remaining 5 modes in turn), repeat the operation in 4 and record the data in Table 3 (time-division and collective jammer record table) or Table 4 (simultaneous division and collective jammer record table).

[0046] 6. Change the output signal frequency of the RF signal source to the selected other frequency points f 1 ~f n , repeat steps 3 to 5, and record the data in the received signal data record, and perform analysis and processing;

[0047] 7. Based on the power values ​​of the signals received by the different polarized antennas tested, the judgment of the receiving polarization is compared with the transmitting polarization mode to determine the polarization diversity performance of the jammer.

[0048] By adopting the technical solution, the present invention has the following advantages:

[0049] A jammer polarization diversity performance test system and method provide a jammer polarization diversity test method in a microwave darkroom, solve the problem that the jammer polarization diversity is difficult to test, and realize automatic switching of the transmitting antenna and the receiving antenna through the designed radio frequency switching circuit, thereby realizing automatic selection of various combination modes of the transmitting antenna polarization, and realizing signal processing through automatic selection of the receiving antenna and data processing, thereby judging the jammer polarization diversity performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 Design of antenna rack and antenna installation plan;

[0051] Figure 2 It is the circuit diagram of the transmitting antenna and the combined switch;

[0052] Figure 3 The circuit diagram for the receiving antenna switch;

[0053] Figure 4 This is the test schematic diagram of the test system used in a microwave darkroom. DETAILED DESCRIPTION

[0054] like Figure 1 , 2 As shown in Figures 3 and 4, a jammer polarization diversity performance test system, the antenna frame is an antenna array with 2 rows and 4 columns, and a wideband antenna is usually selected. First, an antenna frame capable of installing the antenna array must be made. The base of the antenna array is a rectangular plane antenna frame, which can fix and evenly install 2 rows and 4 columns of antennas. After installation, the axes of each antenna are perpendicular to the plane mounting bracket, and the axes are parallel to each other. Among them, 1-4 are signal transmitting antennas, 1' to 4' are signal receiving antennas, and from 1 to 4 (from 1' to 4') are horizontal polarization, vertical polarization, left-hand circular polarization, and right-hand circular polarization antennas respectively; in order to make the jammer antenna as much as possible in the main lobe of all transceiver antennas, the spacing between the 8 transceiver antennas should be relatively small, but this will cause strong mutual coupling between the antennas. This test system mainly adopts the method of filling some absorbing materials between the antennas to physically reduce the influence of antenna mutual coupling.

[0055] The RF switch group can realize the selection of different transmitting antennas and receiving antennas, and realize the switching of different polarization modes of the antennas in sequence through the operating software. Figure 2As shown, it is a switch matrix for antenna transmission, which mainly has 2 SP4T and 3 SP2T switches. The output is connected to 4 signal transmission antennas, numbered 1 to 4, of which 1 SP4T output port is connected to the load. The switching circuit can realize the selection of 4 antennas one by one, with a total of 4 modes, corresponding to the transmission table 1 time-division diversity transmission mode table; it can also realize the selection of four antennas in pairs, respectively realizing 6 selection modes for antennas 1 and 2, 1 and 3, 1 and 4, 2 and 3, 2 and 4, 3 and 4, and the corresponding antenna transmission mode is the following table 2 simultaneous diversity transmission mode table; the receiving antenna switch circuit diagram is as follows Figure 3 As shown, it mainly consists of 1 SP4T switch, and the outputs are respectively connected to 4 signal receiving antennas numbered 1' to 4', so that the 4 receiving antennas can be selected one by one; the input and output switch circuits also require 6 corresponding switch installation boxes and related RF cables, connection plug-ins, 1 switch power supply and control system, and 1 set of control software.

[0056] Table 1 Time-division diversity transmission mode table

[0057] model Mode 1 Mode 2 Mode 3 Mode 4 Gated Antenna 1 2 3 4 Transmit antenna mode Horizontal polarization Vertical polarization Left-hand circular polarization Right-hand circular polarization

[0058] Table 2 Simultaneous diversity transmission mode table

[0059]

[0060] The instrument is configured as 1 signal source, 1 2-way power splitter, and 2 power amplifiers. This combination can provide up to 2 output signals, which are connected to 2 SP4Ts to provide two RF signals for the transmitting antenna; 1 spectrum analyzer is connected to SP4T, and the received 1', 2', 3', and 4' signals are analyzed through the receiving antenna. The signal source and spectrum analyzer can be controlled on an industrial computer, and can realize signal transmission and data reception and processing.

[0061] The test system includes a lifting platform, a signal transmitting and receiving antenna system, a turntable, and a jammer rack. This test system needs to be carried out in a microwave darkroom. The transmitting and receiving antennas are installed on the lifting platform, and the jammer is placed on the jammer rack of the turntable. Through optical alignment, the antenna of the jammer can be aligned with the center of the antenna array.

[0062] Test method of the jammer polarization diversity performance test system:

[0063] 1. Test Description: (1) In this test, the power of each input signal reaching the antenna interface of the jammer should generally be 3dB greater than the sensitivity value of the jammer, so that the jammer can work normally.

[0064] (2) The test is conducted in a microwave darkroom or in an open field. The test site should meet the far-field condition and have no multipath reflection. The center axis of the standard gain antenna group used by the RF signal source to transmit the signal is aligned. The distance R between the jammer antenna and the transmitting antenna should meet the requirements of (1):

[0065] R≥2(D+d) 2 / λ (1)

[0066] Where: D is the maximum size of the measured antenna aperture (equivalent aperture), m; d is the source antenna aperture (equivalent aperture), m; λ is the shortest operating wavelength, m; R is the distance between the source antenna and the measured antenna geometric center, m.

[0067] (3) The RF signal source used for testing should have output power, power indication that meets accuracy requirements, and output frequency indication, and internal pulse modulation capability and pulse parameter indication that meets accuracy requirements.

[0068] (4) Selection of test frequency points: Unless otherwise specified, within the interference frequency range specified in the general product specifications, n (to be determined) frequency points (including upper and lower limit frequency points) are randomly selected according to the uniform distribution of the frequency band or the logarithmic distribution of the frequency.

[0069] 2. Test steps

[0070] 1. According to Figure 4 Build the jammer polarization diversity test system. Connect each instrument and equipment in turn, connect the entire test link, raise the lifting platform, and align the jammer with the central axis of the antenna array.

[0071] 2. The RF signal source is set to internal pulse modulation mode. Unless otherwise specified, the modulation pulse width is 1μs, the pulse repetition frequency is 1kHz, and the output signal frequency is set to the first selected frequency f 1 , the output signal corresponding to each signal in the test must be greater than the sensitivity value; the spectrum analyzer selects the frequency value corresponding to the signal source (for time-division and group-division multi-signal jammer testing, only signal source 1 needs to transmit the signal, and for simultaneous multi-signal jammer testing, the two signal sources are set in the same way).

[0072] 3. Start the jammer under test first, control it to be in normal working state, and set the RF switch of the signal transmitter to mode 1 (the corresponding modes are used for time-division and division-collection system or simultaneous division-collection system);

[0073] 4. Select antennas 1, 2, 3, and 4 (corresponding to horizontal, vertical, left-hand, and right-hand respectively) on the RF switch connected to the signal receiving end, and record the signal power values ​​corresponding to the spectrum analyzer at the frequency points respectively.

[0074] 5. Set the RF switch of the signal transmitter to the remaining modes in turn (for the time-division and collective jammer, select the remaining 3 modes respectively, and for the simultaneous division and collective jammer, select the remaining 5 modes in turn), repeat the operation in 4 and record the data in Table 3 (time-division and collective jammer record table) or Table 4 (simultaneous division and collective jammer record table).

[0075] 6. Change the output signal frequency of the RF signal source to the selected other frequency points f 1 ~f n , repeat steps 3 to 5, and record the data in the following table for analysis.

[0076] Table 3 Time-division reception system jammer receiving signal data record table

[0077]

[0078] Table 4 Simultaneous diversity reception system jammer receiving signal data record table

[0079]

[0080] 7. Based on the power values ​​of the signals received by the different polarized antennas tested, the judgment of the receiving polarization is compared with the transmitting polarization mode to determine the polarization diversity performance of the jammer.

[0081] Example 1: Test data of a certain type of time-division multi-function radar at 2.5 GHz.

[0082]

[0083] From this test data, it can be judged that when the polarization signal is transmitted in time-sharing mode, the jammer can forward the signal of this polarization mode.

[0084] Example 2: Test data of a certain type of simultaneous distribution radar at 9.1 GHz.

[0085]

[0086] From the above measurement results, we can see that this type of jammer has a certain polarization diversity capability. However, since the axis ratio and inclination angle of the forwarded circularly polarized signal are different, the measurement results are somewhat irregular.

Claims

1. A jammer polarization diversity performance test system, characterized in that: The test system includes a signal transmitting system, a signal receiving system, a jammer and a control system; The signal transmission system comprises a signal transmission antenna and a signal transmission amplification processing circuit; the signal transmission antenna is connected to the output end of the control system through a signal radio frequency cable and a signal transmission amplification processing circuit; The signal receiving system comprises a signal receiving antenna and a signal receiving amplification processing circuit; the signal receiving antenna is connected to the receiving end of the control system through a signal radio frequency cable and a signal receiving amplification processing circuit; an antenna array composed of a signal transmitting antenna and a signal receiving antenna is arranged on a lifting platform through an antenna rack, a jammer is arranged on a turntable through an equipment rack, and the lifting platform, the jammer and the turntable are respectively connected to the control system through cables; The antenna array corresponds to the antenna frame, the antenna array is an antenna group of 2 rows and 4 columns, and the antenna array is selected as a wideband antenna; the antenna frame is a rectangular plane antenna frame, and the antenna frame is evenly spaced with 2 rows and 4 columns of antennas, the axis of each antenna is perpendicular to the plane of the antenna frame, and the antenna axis is parallel to the axis of the antenna frame; the antenna frame is sequentially configured with signal transmitting antennas 1-4 on the upper row, and the antenna frame is sequentially configured with 1' to 4' signal receiving antennas on the lower row, and the signal transmitting antennas 1 to 4 and the signal receiving antennas 1' to 4' are horizontally polarized, vertically polarized, left-hand circularly polarized, and right-hand circularly polarized antennas respectively; a jammer antenna is arranged in the main lobe of the signal transmitting antenna and the signal receiving antenna; wherein an absorbing material is arranged between the transmitting and receiving antennas to reduce the spacing and mutual coupling between the transmitting and receiving antennas; The signal transmission amplification processing circuit includes an antenna transmission switch matrix switching circuit and a transmission amplification circuit, the switch matrix switching circuit input end is connected to the transmission amplification circuit, and the switch matrix switching circuit output end is connected to the transmission antenna 1-4; The switch matrix switching circuit includes a four-to-one radio frequency switch SP4T and a two-to-one radio frequency switch SP2T switch; The transmitting amplifying circuit comprises a signal source 1, a signal source 2, a power amplifier 1, and a power amplifier 2; Signal source 1 is connected to power amplifier 1, signal source 2 is connected to power amplifier 2, power amplifier 1 and power amplifier 2 are respectively connected to the first and second four-to-one RF switches SP4T, for providing two output signals, and are respectively connected to two SP4Ts to provide two RF signals for the transmitting antenna; A first output end of the first four-to-one RF switch SP4T is connected to the first transmitting antenna through a RF cable; The second output end is connected to the second transmitting antenna through a radio frequency cable and a two-choice radio frequency switch SP2T; The third output end is connected to the third transmitting antenna through a radio frequency cable and a two-choice radio frequency switch SP2T; The fourth output terminal is connected to the fourth transmitting antenna through a radio frequency cable and a two-choice radio frequency switch SP2T; A first output end of the second four-to-one RF switch SP4T is connected to the second transmitting antenna through a RF cable and the two-to-one RF switch SP2T; The second output end is connected to the third transmitting antenna through a radio frequency cable and a two-choice radio frequency switch SP2T; The third output end is connected to the fourth transmitting antenna through a radio frequency cable and a two-choice radio frequency switch SP2T; The fourth output terminal is connected to the load through a radio frequency cable; (1) It can realize the gating of 1 signal. Signal source 1 transmits the signal. The first 4-to-1 switch is gating. The four antennas are selected one by one through the switch matrix switching circuit. There are 4 modes in total to realize the performance test of the time-division group-controlled jammer. Select mode 1: select antenna 1, the transmitting antenna is horizontally polarized; Selection mode 2: select antenna 2, the transmitting antenna is vertically polarized; Selection mode 3: select antenna 3, the transmitting antenna is left-hand polarization; Selection mode 4: select antenna 4, the transmitting antenna is right-hand polarization; (2) It can select two signals at the same time. Signal source 1 and signal source 2 transmit signals at the same time. The switch matrix switching circuit can select two of the four antennas, including 6 selection modes, to achieve the performance test of the simultaneous group-wise mechanical jammer; Selection mode 1: The selected antennas are antenna 1 and antenna 2, and the transmitting antenna modes are horizontal and vertical polarization; Selection mode 2: The selected antennas are antennas 1 and 3, and the transmitting antenna pattern is horizontal and left-hand circular polarization; Selection mode 3: The selected antennas are 1 and 4, and the transmitting antenna mode is horizontal and right-hand circular polarization; Selection mode 4: The selected antennas are 2 and 3, and the transmitting antenna mode is vertical and left-hand circular polarization; Selection mode 5: The selected antennas are 2 and 4, and the transmitting antenna mode is vertical and right-hand circular polarization; Selection mode 6: The selected antennas are 3 and 4, and the transmitting antenna modes are left-hand and right-hand circular polarization; The signal receiving amplification processing circuit comprises an antenna receiving switch matrix switching circuit and a receiving amplification circuit. The output end of the antenna receiving switch matrix switching circuit is connected to the receiving amplification circuit, and the input end of the antenna receiving switch matrix switching circuit is connected to receiving antennas 1' to 4'. The antenna receiving switch matrix switching circuit is used to select four receiving antennas one by one; the input end of the four-to-one radio frequency switch is connected to the spectrum analyzer through a low-noise power amplifier; the spectrum analyzer is connected to SP4T, and performs signal analysis on the received 1', 2', 3', and 4' signals respectively through the receiving antenna; the signal source and the spectrum analyzer realize control signal transmission and data reception and processing through an industrial computer.

2. The jammer polarization diversity performance test system as claimed in claim 1, characterized in that: The system testing method steps are as follows:

1. Test technical requirements: (1) In this test, the power of each input signal reaching the antenna interface of the jammer must be 3 dB greater than the sensitivity value of the jammer, so that the jammer can work normally; (2) The test is carried out in a microwave darkroom. The test site should meet the far-field conditions and have no multipath reflection. The central axis of the standard gain antenna group used by the RF signal source to transmit the signal is aligned; The distance R between the jammer antenna and the transmitting antenna should meet the following requirements: R≥2(D+d) 2 / l Where: D is the aperture of the antenna under test, the maximum size of the equivalent aperture; d is the aperture of the source antenna, the equivalent aperture size; λ is the shortest operating wavelength; R is the distance between the geometric center of the source antenna and the antenna under test; (3) The RF signal source used for testing shall have output power, power indication and output frequency indication that meet the accuracy requirements, internal pulse modulation capability and pulse parameter indication that meet the accuracy requirements; (4) Selection of test frequency points: within the interference frequency range, evenly distributed by frequency band or evenly distributed by the logarithm of frequency, arbitrarily select n frequency points, including upper and lower limit frequency points; 2. Test steps: 1) Build the jammer polarization diversity test system, connect each instrument and equipment in turn, connect the entire test link, raise the lifting platform, and align the jammer with the central axis of the antenna array; This test system needs to be carried out in a microwave darkroom. The transmitting and receiving antennas are installed on the lifting platform, and the jammer is placed on the jammer rack of the turntable. Through optical alignment, the antenna of the jammer can be aligned with the center of the antenna array. 2) Set the RF signal source to internal pulse modulation mode, the modulation pulse width is 1μs, the pulse repetition frequency is 1kHz, and the output signal frequency is set to the first selected frequency f1. The output signal corresponding to each signal in the test must be greater than the sensitivity value; the spectrum analyzer selects the frequency value corresponding to the signal source, that is, for the time-division multi-function jammer test, only signal source 1 needs to transmit the signal, and for the simultaneous multi-function multi-function jammer test, the two signal sources are set in the same way; 3) Start the jammer under test first, control it to be in normal working state, and set the RF switch of the signal transmitter to mode 1, that is, time-division and collective system or simultaneous and collective system, respectively adopt the corresponding mode; 4) Select antennas 1, 2, 3, and 4 in turn on the RF switch connected to the signal receiving end, which correspond to horizontal, vertical, left-hand, and right-hand respectively, and record the signal power value corresponding to the spectrum analyzer at the frequency point respectively; 5) Set the RF switch of the signal transmitter to the remaining modes in turn, that is, select the remaining 3 modes for the time-division and collective jammers, and select the remaining 5 modes for the simultaneous-division jammers, repeat the operation in 4 and record the data, that is, the time-division and collective jammers record or the simultaneous-division jammers record; 6) Change the output signal frequency of the RF signal source to the selected other frequency points f1~f n , repeat steps 3 to 5, and record the data in the received signal data record, and perform analysis and processing; 7) According to the power value of the received signal of the different polarized antennas tested, the judgment of the receiving polarization is compared with the transmitting polarization mode to determine the polarization diversity performance of the jammer.

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