CN211627810U - A testing device for full-link receiving pattern of phased array radar - Google Patents

Abstract

The utility model discloses a phased array radar full link reception directional diagram's testing arrangement relates to radar test technical field. The testing device comprises a near field testing system, a PC (personal computer) and auxiliary testing equipment, and the wave beams are directed to a certain wave position to be tested through a phase shifting circuit of the auxiliary testing equipment, so that the test of the direction of all the wave beams is realized, namely, the normal wave beams can be tested, and the wave beams in other directions can also be tested; the test complexity is reduced through the up-converter of the auxiliary test equipment, the requirement on a near field test system is reduced, the test of a full-receiving radio frequency link flow can be realized, and the test parameters are more complete.

Description

A testing device for full-link receiving pattern of phased array radar

technical field

The utility model belongs to the technical field of radar, in particular to a testing device for a full-link receiving pattern of a phased array radar.

Background technique

The antenna pattern represents the distribution of the radiated energy of the antenna in space, and reflects the performance index and working state of the antenna. By measuring the antenna pattern, important antenna parameters such as the direction coefficient, gain, half-power beamwidth and sidelobe level of the antenna can be determined. Analyzing the radiation characteristics of the antenna can provide analysis data for the debugging, installation, maintenance and overhaul of the antenna during use, and determine whether the antenna performance indicators meet the requirements and whether the antenna is faulty.

At present, there are three main methods or devices for testing the receiving pattern of phased array radar in the industry:

The first is to do a separate pattern test only for the passive part of the antenna. This method is not a full-link test, only the performance of the antenna can be obtained, and only the normal beam can be tested.

The second is to test the pattern of the antenna + TR components together, as shown in the dashed box in Figure 1. The main disadvantages of this method are: a. It is not a full-link test, and can only reflect the antenna + TR radio frequency For the scheme that each channel includes a frequency conversion link, the frequency conversion and intermediate frequency circuits cannot be measured, and the performance of the whole link cannot be reflected; b. For general phased array radars, if the TR component has a phase shifting function, it can To test the pattern of each beam, for the receive chain using digital beamforming (DBF) technology, the TR component itself does not need a phase shift function, so only the normal pattern can be tested.

The third method is to use the whole phased array radar as a whole DUT to conduct the pattern test. This test method is a full-link test. The main disadvantage of this method is that it requires complex site conditions and needs to have the The far-field test conditions require large test sites for phased array radars with lower frequency bands, and the test results are easily affected by the environment.

Utility model content

Aiming at the deficiencies of the prior art, the utility model provides a testing device for the full-link receiving pattern of the phased array radar, so as to realize the test of all beam patterns, and realize the full receiving when the near-field test system does not have the function of frequency conversion. RF link test.

The utility model solves the above-mentioned technical problems through the following technical solutions: a testing device for the full-link receiving pattern of a phased array radar, comprising: a near-field testing system and a PC respectively connected with the radar to be tested; The feature is that it also includes: auxiliary test equipment respectively connected with the near-field test system, the PC and the radar under test;

The auxiliary test equipment includes a multi-channel phase-shift circuit, a combiner and an up-converter; the input ends of the multi-channel phase-shift circuits are respectively connected with the multi-channel intermediate frequency circuits of the radar under test, and the output ends of the multi-channel phase-shift circuits are respectively connected. is connected to the input end of the combiner; the output end of the combiner is connected to the input end of the up-converter, and the output end of the up-converter is connected to the near-field test system; the up-converter is connected to the near-field test system; The input end of the frequency converter is also connected with the local oscillator circuit of the radar under test respectively.

In the device of the utility model, during the receiving pattern test, the PC controls the radar under test to be in the receiving test mode, the radar under test generates the corresponding timing control signal in the receiving test mode, and the near-field test system radiates the radio frequency reference signal through the probe It is fed to the antenna front of the radar under test, and the RF reference signal is converted into an intermediate frequency signal through various TR components and frequency conversion circuits in the radar under test, and the intermediate frequency signal is fed to the phase-shift circuit in the auxiliary test equipment through the intermediate frequency circuit. After the phase-shifting circuit is phase-shifted (controlled by the PC to make the beam point to a certain wave position to be tested), it is synthesized by the combiner, and then the up-converter converts the frequency to the RF signal and feeds it to the near-field test system. The near-field test The system compares the RF signal with the output reference RF signal to obtain near-field amplitude and phase data. After scanning the entire antenna array, the far-field pattern can be obtained, that is, the receiving pattern; the device uses the shift of the auxiliary test equipment. Phase function, can carry out all beam pointing tests, the use of the up-converter and the local oscillator circuit of the radar under test can offset the error from the frequency conversion and improve the test accuracy; the device does not have the frequency conversion function in the near-field test system. It can test the full-receive RF link process, making the test parameters more complete, reducing the test complexity and the cost of the test equipment; the device uses the near-field test system to obtain the far-field receiving pattern, and does not need to have a far-field receiving pattern. Field test conditions, reducing the requirements for field conditions.

Further, one of the phase-shifting circuits includes a first-level switch circuit, a first-level attenuation circuit, a first-level amplifier circuit, a transformer circuit, a second-level switch circuit, an analog phase-shift circuit, a second-level attenuation circuit, and a second-level amplifier connected in sequence. A circuit and a filter circuit; one input end of the first-stage switch circuit is connected to an intermediate frequency circuit of the radar under test, and an output end of the filter circuit is connected to the input end of the combiner.

Further, the first-level switch circuit and the second-level switch circuit are both circuits based on a single-pole double-throw switch whose model is HMC349AMS8GE.

Further, the first-level attenuation circuit and the second-level attenuation circuit are circuits based on attenuators whose model is RFSA3714.

Further, the analog phase shift circuit includes a phase shifter U11 with a model of JSPHS-51, the first pin of the phase shifter U11 is connected to the output end of the secondary switch circuit through a capacitor C30, and the seventh pin of the phase shifter U11 is connected to the output end of the secondary switching circuit. It is connected to the input terminal of the secondary attenuation circuit through a series circuit formed by a capacitor C31, a resistor R16 and a capacitor C29.

beneficial effect

Compared with the prior art, the utility model provides a test device for the full-link receiving pattern of the array-controlled radar, which points the beam to a certain wave position to be tested through the phase-shift circuit of the auxiliary test equipment, so as to realize All beam pointing tests can be tested, that is, it can test both normal beams and beams in other directions; the upconverter of auxiliary test equipment reduces the complexity of the test, and also reduces the requirements for the near-field test system, Realize the test of the full receive RF link process, making the test parameters more complete. The device has the advantages of simple structure, convenient operation and strong practical significance.

Description of drawings

In order to illustrate the technical solutions of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only one embodiment of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic diagram of the second type of testing device in the background technology of the present utility model;

Fig. 2 is the structural block diagram of the testing device in the embodiment of the present invention;

3 is a circuit schematic diagram of a phase-shifting circuit in an embodiment of the present invention, wherein FIG. 3(a) is a circuit schematic diagram mainly based on switch U6, and FIG. 3(b) is based on attenuator U7 and amplifier U8 as The main circuit schematic diagram, Figure 3(c) is the circuit schematic diagram based on the transformer U9 and the switch U10, Figure 3(d) is the circuit schematic diagram based on the phase shifter U11, and Figure 3(e) is based on the circuit diagram. The circuit schematic diagram of the attenuator U12 and the amplifier U14 as the main circuit, Fig. 3(f) is the circuit diagram of the filter U13 as the main circuit; the capacitor C16 in Fig. 3(a) and the fifth pin of U7 in Fig. 3(b) Connection, the resistor R5 in Fig. 3(b) is connected with the capacitor C19 in Fig. 3(c), the third pin of U10 in Fig. 3(c) is connected with the capacitor C30 in Fig. 3(d), the capacitor in Fig. 3(d) C29 is connected to the 5th pin of U12 in Fig. 3(e), and the 3rd pin of U14 in Fig. 3(e) is connected to the capacitor C33 in Fig. 3(f).

Detailed ways

The technical solutions in the present utility model will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

As shown in FIG. 2 , a test device for a phased array radar full-link receiving pattern provided by the present invention includes: a near-field test system and a PC respectively connected to the radar under test, and a near-field test system and a PC respectively connected to the near-field radar. Auxiliary test equipment for connection of test system, PC and radar under test. The auxiliary test equipment includes a multi-channel phase-shifting circuit, a combiner and an up-converter; the input ends of the multi-channel phase-shifting circuit are respectively connected with the multi-channel intermediate frequency circuit of the radar under test, and the output end of the multi-channel phase-shifting circuit is connected with the combiner. The output end of the combiner is connected to the input end of the up-converter, and the output end of the up-converter is connected to the near-field test system; the up-converter is also connected to the local oscillator circuit of the radar under test.

The phase-shifting circuit in the auxiliary test equipment is controlled by the PC to perform signal phase-shifting on each channel of the radar main body under test, so as to test all required beam pointing patterns. If the radio frequency link does not have the function of receiving phase-shifting Phased array radars can generally only test one normal beam, for example, X-band phased array radars (only 0° beams can be tested without using the phase-shifting function of the auxiliary test equipment), while the utility model Using the phase-shifting function of the phase-shifting circuit, the ±45° beam (the radar's designed beam area) can be tested. The function of the combiner is to combine the data of multiple channels into one. The function of the up-converter is to use the local oscillator signal transmitted by the radar body under test to complete the frequency conversion function from intermediate frequency to radio frequency, and finally transmit the radio frequency signal to the near-field test system for testing. The up-converter reduces the complexity of the test, and at the same time The requirements for the near-field test system are reduced, and the local oscillator circuit of the radar body under test provides the up-converter with a local oscillator signal consistent with the frequency conversion circuit of the radar body, making the test results more accurate and credible.

Auxiliary test equipment can be used to test the full-receive RF link process. Generally, when a near-field test system without frequency conversion function is used for testing, only the antenna can be tested alone, or the TR component + antenna can be tested, but the frequency conversion link cannot be tested. However, adding the frequency conversion function is relatively expensive in the near-field test system, and the link is complex. After using the auxiliary test equipment, the full-receive RF link process can be tested on the premise that the near-field test system does not have the frequency conversion function. The test parameters are more complete, and the complexity of the test conditions is reduced, the requirements for the near-field test system are reduced, and the cost of the test equipment is reduced.

As shown in FIG. 3 , one phase-shifting circuit includes a first-stage switching circuit U6, a first-stage attenuation circuit U7, a first-stage amplifying circuit U8, a transformer circuit U9, a second-stage switching circuit U10, an analog phase-shifting circuit U11, a second-stage switching circuit U10, and a second-stage Attenuation circuit U12, secondary amplifier circuit U14 and filter circuit U13; one input end (RF1 end) of the primary switch circuit U6 is connected to an intermediate frequency circuit of the radar under test, and the output end of the filter circuit U13 is connected to the input end of the combiner Connection; the other input end (RF2 end) of the primary switch circuit U6 is connected with the corresponding circuit when other functions need to be realized, and does not need to be connected when other functions are not needed. In this embodiment, there is no need to implement other functions, therefore, the RF2 terminal of the first-stage switch circuit U6 does not need to be connected to other circuits. In this embodiment, the primary switch circuit U6 and the secondary switch circuit U10 are both circuits based on SPDT switches with the model HMC349AMS8GE. The SPDT switch with the model HMC349AMS8GE has high isolation, low insertion loss, high Input linearity, high power handling and other advantages.

As shown in Figure 3, the first-level attenuation circuit U7 and the second-level attenuation circuit U12 are based on the attenuator model RFSA3714. The specific attenuation of the attenuator is determined according to which angle the beam points to; the model is RFSA3714. The 7-bit digital step attenuator features high linearity over the entire 31.75dB gain control range with a 0.25dB step size and low insertion loss of 1.5dB at 2GHz. For the control of the attenuation of the attenuator, reference may be made to the patent document with the application number CN200910189482.9 titled a radio frequency front-end device and its gain control method and system.

As shown in Figure 3, the analog phase shift circuit includes a phase shifter U11 with a model of JSPHS-51. The first pin of the phase shifter U11 is connected to the output end of the secondary switch circuit through a capacitor C30, and the seventh The pin is connected to the input end of the secondary attenuation circuit through the series circuit formed by the capacitor C31, the resistor R16 and the capacitor C29. Model JSPHS-51 analog phase shifters have low insertion loss, excellent VSWR, excellent solderability and strain relief.

In the utility model, the combiner and the up-converter are existing products, which are sold in the market, and the combiner and the up-converter of the corresponding model can be selected according to needs.

The near-field test system is connected to the control circuit of the radar under test through a radio frequency interface (high-precision clock) and an LVTTL level interface (pulse synchronization signal). The main function of the near-field test system is to use the near-field test principle, use the near-field scanning frame to obtain the near-field blessing phase data of the radar under test, and calculate the far-field pattern. The system is generally divided into with frequency conversion function and without frequency conversion function. The near-field test system with frequency conversion function has complex links and expensive equipment. In this embodiment, the near-field test system has no frequency conversion function and is an existing technology, which can be customized by the manufacturer according to the test needs. For example, a microwave anechoic chamber is a kind of near-field test system. The high-performance vector network analyzer is the core, supplemented by the high-performance RF amplifier N4985A unit. The whole test is self-contained. Different test frequency bands and different test methods share test instruments. By replacing the reference/test mixing components of different frequency bands and the corresponding Connecting cables and adapters can complete the measurement of various antennas and various parameters of antennas in different frequency bands. You can also refer to the patent document with the authorization announcement number CN107329003B and the title is the method of optimizing the SAR antenna pattern test, which discloses that in the environment of the plane near-field test system, the near-field test data of the corresponding wave level is obtained by using the plane near-field test system. , and then complete the near-field test data transformation to obtain the SAR antenna test pattern; or Baidu Encyclopedia antenna near-field test system, there are also corresponding introductions.

The working principle of the utility model is as follows: during the receiving pattern test, the PC controls the radar under test to be in the receiving test mode, the radar under test generates a corresponding timing control signal in the receiving test mode, and the near-field test system radiates radio frequency through the probe The reference signal is fed to the antenna array of the radar under test, and the RF reference signal is converted to an intermediate frequency signal through various TR components and frequency conversion circuits in the radar under test, and the intermediate frequency signal is fed to the phase shift circuit in the auxiliary test equipment through the intermediate frequency circuit. The intermediate frequency signal is phase-shifted by the phase-shift circuit (controlled by the PC to make the beam point to a certain wave position to be tested), and then synthesized by the combiner, and then converted to the RF signal by the up-converter and fed to the near-field test system. The field test system compares the RF signal with the output reference RF signal to obtain near-field amplitude and phase data. After scanning the entire antenna array, the far-field pattern can be obtained, that is, the receiving pattern can be obtained.

The device of the utility model utilizes the phase-shifting function of the auxiliary test equipment to perform all beam pointing tests, and utilizes the up-converter and the local oscillator circuit of the radar to be tested to offset the error from the frequency conversion, thereby improving the test accuracy; In the case that the near-field test system does not have the frequency conversion function, the test of the full-receive RF link process can be carried out to make the test parameters more complete.

The above disclosure is only the specific embodiment of the present invention, but the protection scope of the present invention is not limited to this. Any person skilled in the art can easily think of changes or Modifications should be covered within the protection scope of the present invention.

Claims (5)

1. A test device for a full-link reception directional diagram of a phased array radar comprises: near field test system, PC that is connected with the radar under test respectively, its characterized in that still includes:

the auxiliary test equipment is respectively connected with the near field test system, the PC and the tested radar;

the auxiliary test equipment comprises a multi-path phase shift circuit, a combiner and an up-converter; the input ends of the multiple paths of phase shift circuits are respectively connected with multiple paths of intermediate frequency circuits of the radar to be detected, and the output ends of the multiple paths of phase shift circuits are connected with the input end of the combiner; the output end of the combiner is connected with the input end of the up-converter, and the output end of the up-converter is connected with the near field test system; and the input end of the up-converter is also respectively connected with a local oscillator circuit of the radar to be detected.

2. The test apparatus of claim 1, wherein: one path of the phase-shifting circuit comprises a primary switch circuit, a primary attenuation circuit, a primary amplification circuit, a transformer circuit, a secondary switch circuit, an analog phase-shifting circuit, a secondary attenuation circuit, a secondary amplification circuit and a filter circuit which are connected in sequence; one input end of the primary switch circuit is connected with one path of intermediate frequency circuit of the radar to be detected, and the output end of the filter circuit is connected with the input end of the combiner.

3. The test apparatus of claim 2, wherein: the primary switch circuit and the secondary switch circuit are both circuits mainly comprising a single-pole double-throw switch with the model number of HMC349AMS8 GE.

4. The test apparatus of claim 2, wherein: the first-stage attenuation circuit and the second-stage attenuation circuit are both circuits mainly comprising attenuators with the models of RFSA 3714.

5. The test apparatus of claim 2, wherein: the analog phase shift circuit comprises a phase shifter U11 with the model number of JPHS-51, the 1 st pin of the phase shifter U11 is connected with the output end of the secondary switch circuit through a capacitor C30, and the 7 th pin of the phase shifter U11 is connected with the input end of the secondary attenuation circuit through a series circuit consisting of a capacitor C31, a resistor R16 and a capacitor C29.

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