Multi-probe near-field electromagnetic characteristic test system and method based on ultra-wideband plane wave synthesis method

Abstract

The invention relates to a multi-probe near-field electromagnetic characteristic test system and method based on an ultra-wide-band plane wave synthesis method, and the system comprises a test darkroom, a plurality of ultra-wide-band plane wave synthesizers, one or more supports, and a tested object. The plurality of ultra wide band plane wave synthesizers are arranged on one or more brackets, and the tested object is arranged in one bracket or among the plurality of brackets; at least one of the plurality of ultra-wideband plane wave synthesizers serves as a transmitting antenna, a transmitting plane wave probe of the ultra-wideband plane wave synthesizers is used for transmitting uniform plane waves to a measured object, the rest ultra-wideband plane wave synthesizers serve as receiving antennas, and receiving plane wave probes of the ultra-wideband plane wave synthesizers are used for receiving the uniform plane waves reflected by the measured object. Therefore, the double-station or multi-station electromagnetic characteristic of the tested object can be tested. According to the invention, measurement of various electromagnetic characteristics such as a target double-station / multi-station radar scattering cross section and an antenna radiation pattern can be realized.

Description

Technical Field

[0001] The invention relates to electromagnetic characteristics and antenna near-field testing technology, and in particular to a multi-probe near-field electromagnetic characteristics testing system and method based on an ultra-wideband plane wave synthesis method. Background Art

[0002] The plane wave measurement method is the most common test method in the field of microwave measurement. Plane wave test methods can be divided into two categories: near-field measurement and far-field measurement. Since far-field measurement is limited by far-field conditions, plane wave near-field measurement is becoming more and more the mainstream method in the field of microwave measurement.

[0003] The current near-field measurement methods are mainly divided into spherical near-field, cylindrical near-field or planar near-field. The plane wave probe is mainly used to scan and sample the near-field area of ​​the object to be measured, and the far-field electromagnetic parameters of the object to be measured are obtained through the near-field transformation of the data. However, this type of test method is powerless to measure large-sized targets. Summary of the invention

[0004] Purpose of the invention: One purpose of the present invention is to provide a multi-plane wave probe near-field electromagnetic characteristics test system for achieving a target dual-station / multi-station based on an ultra-wideband plane wave synthesis method.

[0005] Another object of the present invention is to provide a near-field electromagnetic characteristics testing method based on the system.

[0006] Technical solution: The multi-probe near-field electromagnetic characteristic test system based on the ultra-wideband plane wave synthesis method described in the present invention comprises a test darkroom, multiple ultra-wideband plane wave synthesizers, one or more ultra-wideband plane wave synthesizer mounting brackets and a test object, wherein the one or more ultra-wideband plane wave synthesizer mounting brackets are arranged in the test darkroom, the multiple ultra-wideband plane wave synthesizers are arranged on one or more ultra-wideband plane wave synthesizer mounting brackets, and the test object is arranged in one bracket or between multiple brackets; at least one of the multiple ultra-wideband plane wave synthesizers is used as a transmitting antenna, and its transmitting plane wave probe is used to transmit uniform plane waves to the test object, and the remaining ultra-wideband plane wave synthesizers are used as receivers, and their receiving plane wave probes are used to receive uniform plane waves reflected back by the test object, so as to realize the test of dual-station or multi-station electromagnetic characteristics of the test object.

[0007] Optionally, the one or more ultra-wideband plane wave synthesizer mounting brackets include arcs, circles and polygons.

[0008] Optionally, the one or more ultra-wideband plane wave synthesizer mounting brackets include a flat surface and a curved surface;

[0009] Optionally, the angle between the planes where any two of the multiple ultra-wideband plane wave synthesizer mounting brackets are located is φ, 0≤φ≤180°.

[0010] Optionally, the one or more ultra-wideband plane wave synthesizer mounting brackets are evenly arranged in the test darkroom, the multiple ultra-wideband plane wave synthesizers are evenly set on the one or more ultra-wideband plane wave synthesizer mounting brackets, and the object under test is set at the center position of the one or more ultra-wideband plane wave synthesizer mounting brackets.

[0011] Optionally, the angle between the ultra-wideband plane wave synthesizer as a transmitting antenna and the ultra-wideband plane wave synthesizer as a receiver and the line connecting the object to be measured is θ, 0≤θ≤180°.

[0012] Optionally, the system also includes a turntable, a control device and a test instrument, the object under test is mounted on the turntable, the control device is used to control the steering angle and steering speed of the turntable, and the control device controls the test instrument to generate a microwave signal and send it to an ultra-wideband plane wave synthesizer serving as a transmitting antenna; the ultra-wideband plane wave synthesizer serving as a receiver receives the uniform plane wave reflected back by the object under test and transmits it to the test instrument.

[0013] Optionally, the test instruments include a vector network analyzer, a spectrum analyzer, a signal generator and a power meter.

[0014] Optionally, the multiple ultra-wideband plane wave synthesizers include multiple tightly coupled antenna array modules and multi-stage ultra-wideband power dividers, the multiple tightly coupled antenna array modules include M tightly arranged ultra-wideband antenna units, the multi-stage ultra-wideband power divider realizes equal-amplitude and in-phase power distribution of signals, and realizes equal-amplitude and in-phase feeding of each ultra-wideband antenna unit through equal-amplitude and in-phase cables.

[0015] The test method corresponding to the above system includes the following steps:

[0016] (1) The control device controls the object to be measured to be located at a predetermined distance, azimuth and elevation angle;

[0017] (2) The control device controls the test instrument to generate a microwave signal, and the microwave signal passes through at least one ultra-wideband plane wave synthesizer and transmits a uniform plane wave through its corresponding transmitting plane wave probe;

[0018] (3) After the uniform plane wave irradiates the object under test, the reflected signal of the object under test is received by at least one receiving plane wave probe and returned to the test instrument through its corresponding ultra-wideband plane wave synthesizer, thereby realizing dual-station or multi-station near-field electromagnetic characteristics testing;

[0019] (4) Record relevant measured signals and data.

[0020] Beneficial effects: Compared with the prior art, the significant technical effects of the present invention are: (1) efficient and high-precision measurement of various electromagnetic characteristics such as dual-station or multi-station radar cross-section and antenna radiation pattern of the target is achieved in a relatively small test space; (2) the ultra-wideband plane wave synthesis technology based on the Huygens principle is adopted, which has the advantages of short test distance and small footprint. Compared with the single-station, dual-station and multi-station radar cross-section of the target in the compact field test system, the test space is reduced by three quarters; (3) the multi-plane wave probe can flexibly increase or decrease the number of antenna array modules according to the size of the target to be tested, and generate a large-scale high-quality quiet zone. The equipment can be upgraded on the basis of the existing scale in the later stage, solving the problems of difficult upgrade, small quiet zone size and high construction cost of traditional compact field and far-field plane wave test systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0022] Figure 2 A schematic diagram of the dual-station RCS test principle of the system of the present invention;

[0023] Figure 3 It is a structural schematic diagram of an ultra-wideband plane wave synthesizer in a specific embodiment of the present invention;

[0024] Note: 1-test chamber, 2-ultra-wideband plane wave synthesizer, 3-bracket, 4-turntable, 5-object under test, 6-control equipment and test instruments, 7-plane wave, 21-transmitting plane wave probe, 22-receiving plane wave probe, 201-ultra-wideband antenna unit, 202-equal amplitude and in-phase feeding network, 8-edge compensation structure, 9-tightly coupled antenna array module, 10-stable amplitude and phase cables. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0026] The technical solutions provided by various embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0027] See also Figure 1The core of the present application is a receiving and transmitting antenna near-field test system composed of multiple ultra-wideband plane wave synthesizers 2 (including plane wave probes), that is, a multi-plane wave probe near-field electromagnetic characteristics test system. The test system includes a test darkroom 1 and multiple ultra-wideband plane wave synthesizers 2, a bracket 3, a turntable 4, a test object 5, a control device and a test instrument 6, etc., which are arranged in the test darkroom 1. The multiple ultra-wideband plane wave synthesizers 2 are respectively installed at different positions of the bracket 3, and the test object 5 is installed on the turntable 4. The multiple ultra-wideband plane wave synthesizers are used to transmit and receive ultra-wideband wireless signals, and the control device and the test instrument are used to test the electromagnetic characteristics of the test object on the turntable. The ultra-wideband plane wave synthesizer 2 generates an equal-amplitude and in-phase radiation signal through a large number of tightly coupled ultra-wideband antenna units 201 through an equal-amplitude and in-phase feeding network 202, and forms a plane wave 7 in the near area of ​​the synthesizer. The multi-plane wave probe near-field electromagnetic characteristics test system realizes the target dual-station / multi-station radar cross section (RCS) test through multiple ultra-wideband plane wave synthesizers 2. The ultra-wideband plane wave synthesizer 2 as a transmitting antenna emits a plane wave and irradiates the object under test in the near zone; similarly, according to the electromagnetic reciprocity principle, the ultra-wideband plane wave synthesizer 2 as a receiving antenna can also receive scattered electromagnetic waves equivalent to those in the far zone in the near zone.

[0028] The bracket 3 includes but is not limited to arc, circle, polygon, and can also be a plane and / or a curved surface; the number of the brackets 3 is N, and N is a positive integer greater than or equal to 1; when N is a positive integer greater than 1, the angle between the planes where any two brackets 3 are located is φ, 0≤φ≤180°.

[0029] Preferably, when there is one bracket 3, multiple ultra-wideband plane wave synthesizers 2 are evenly arranged on the bracket 3, and the object under test 5 is arranged at the center position of the bracket 3, so that the multiple ultra-wideband plane wave synthesizers 2 transmit and receive ultra-wideband wireless signals symmetrically, thereby improving the test accuracy.

[0030] Preferably, when there are multiple brackets 3, multiple ultra-wideband plane wave synthesizers 2 are evenly arranged on the multiple brackets 3, and the object under test 5 is arranged at the center position of the area formed by the multiple brackets 3, so that the multiple ultra-wideband plane wave synthesizers 2 transmit and receive ultra-wideband wireless signals symmetrically, thereby improving the test accuracy.

[0031] The angle (ie, bistatic angle) between the lines connecting the ultra-wideband plane wave synthesizer used as a transmitting antenna and the ultra-wideband plane wave synthesizer used as a receiving antenna in the multiple ultra-wideband plane wave synthesizers 2 and the object under test 5 is θ, 0≤θ≤180°.

[0032] Preferably, the object to be measured 5 is mounted on the turntable 4, and the movement of the turntable is controlled to achieve that the object to be measured is located at a preset position.

[0033] See also Figure 2 For dual-station RCS testing, Figure 2 The two ultra-wideband plane wave synthesizer heads 2 are used as transmitting antennas and receiving antennas respectively, and their corresponding probes are transmitting plane wave probes 21 and receiving plane wave probes 22 respectively. The transmitting plane wave probes and receiving plane wave probes respectively generate uniform plane waves through a large number of tightly coupled antenna units. For the near-zone object 5, the transmitted and received electromagnetic waves can be equivalent to the far-zone electromagnetic waves. The angle between the connecting line of the transmitting plane wave probe 21 and the receiving plane wave probe 22 and the object 5 is the bistatic angle.

[0034] See also Figure 3 In this embodiment, the ultra-wideband plane wave synthesizer 2 includes a plurality of tightly coupled antenna array modules 9 and a multi-stage ultra-wideband power divider 202. The plurality of tightly coupled antenna array modules 9 include M closely arranged antenna units 201, where M is a positive integer greater than or equal to 1. Edge compensation structures 8 are provided on both sides of the ultra-wideband plane wave synthesizer 2. The multi-stage ultra-wideband power divider 202 realizes equal-amplitude and in-phase power distribution of the signal, and realizes equal-amplitude and in-phase feeding of each antenna unit 201 through an equal-amplitude and in-phase cable 10. The plurality of tightly coupled antenna array modules 9 and the multi-stage ultra-wideband power divider 11 synthesize uniform plane waves in the near field of the ultra-wideband plane wave synthesizer.

[0035] The multi-plane wave probe near-field electromagnetic characteristics test system is a single-station / dual-station / multi-station near-field electromagnetic characteristics test system based on the plane wave synthesis method of the Huygens principle. Based on the test system, the measurement of various electromagnetic characteristics such as the single-station / dual-station / multi-station radar cross section (RCS) and antenna radiation pattern of the target can be achieved, and it has the advantages of strong measurement capability, large quiet zone size, small quiet zone amplitude and phase ripples, small footprint, simple debugging, and easy scale expansion.

[0036] The testing principle of the multi-plane wave probe near-field electromagnetic characteristics testing system is:

[0037] Huygens' principle states that any point on the ongoing wavefront can be regarded as a point source of spherical secondary waves, and the wavefront at any subsequent time can be regarded as the envelope of these secondary waves. According to Huygens' principle, each unit of a tightly coupled antenna array emits a spherical wave, and any point on its wavefront can be regarded as the source of a secondary wave. When each tightly coupled antenna unit is fed with equal amplitude and in phase, the wavefronts of these antenna units are superimposed on each other, making the envelope of all secondary waves of the antenna array a synthetic uniform plane wave.

[0038] The testing method of the multi-plane wave probe near-field electromagnetic characteristics testing system comprises the following steps:

[0039] Step 1, installing the object 5 to be measured on the turntable 4;

[0040] Step 2, the control device controls the coordinate position and rotation angle of the turntable 4 so that the object to be measured is located at a predetermined distance, azimuth and pitch angle;

[0041] Step 3: The control device controls the test instrument to generate a microwave signal, which passes through at least one ultra-wideband plane wave synthesizer and transmits a uniform plane wave through its corresponding transmitting plane wave probe;

[0042] Step 4: After the uniform plane wave irradiates the object under test, the reflected signal of the object under test is received by at least one receiving plane wave probe, and is returned to the test instrument through its corresponding ultra-wideband plane wave synthesizer to realize dual-station or multi-station near-field electromagnetic characteristics test;

[0043] Step 5: Record relevant measured signals and data;

[0044] Test instruments include, but are not limited to, vector network analyzers, spectrum analyzers, signal generators, and power meters.

Claims

1. A multi-probe near-field electromagnetic characteristics test system based on ultra-wideband plane wave synthesis method, characterized in that: The invention comprises a test darkroom (1), a plurality of ultra-wideband plane wave synthesizers (2), one or more ultra-wideband plane wave synthesizer mounting brackets (3) and a test object (5), wherein the one or more ultra-wideband plane wave synthesizer mounting brackets (3) are arranged in the test darkroom (1), the plurality of ultra-wideband plane wave synthesizers (2) are arranged on the one or more ultra-wideband plane wave synthesizer mounting brackets (3), and the test object (5) is arranged in one bracket (3) or between a plurality of brackets (3); at least one of the plurality of ultra-wideband plane wave synthesizers (2) is used as a transmitting antenna, and its transmitting plane wave probe is used to transmit a uniform plane wave to the test object (5); the remaining ultra-wideband plane wave synthesizers (2) are used as receiving antennas, and their receiving plane wave probes are used to receive the uniform plane wave reflected back by the test object (5), so as to realize the test of the dual-station or multi-station electromagnetic characteristics of the test object (5).

2. The multi-probe near-field electromagnetic characteristics test system based on ultra-wideband plane wave synthesis method according to claim 1 is characterized in that: The one or more ultra-wideband plane wave synthesizer mounting brackets (3) include arc, circle and polygon shapes.

3. The multi-probe near-field electromagnetic characteristics test system based on ultra-wideband plane wave synthesis method according to claim 1, characterized in that: The one or more ultra-wideband plane wave synthesizer mounting brackets (3) include a flat surface and a curved surface.

4. A multi-probe near-field electromagnetic characteristics test system based on ultra-wideband plane wave synthesis method according to any one of claim 1, characterized in that: The angle between the planes where any two of the plurality of ultra-wideband plane wave synthesizer mounting brackets (3) are located is φ, 0≤φ≤180°.

5. A multi-probe near-field electromagnetic characteristics test system based on ultra-wideband plane wave synthesis method according to any one of claim 1, characterized in that: The one or more ultra-wideband plane wave synthesizer mounting brackets (3) are evenly arranged in a test darkroom (1); the plurality of ultra-wideband plane wave synthesizers (2) are evenly arranged on the one or more ultra-wideband plane wave synthesizer mounting brackets (3); and the object to be tested (5) is arranged at a central position of the one or more ultra-wideband plane wave synthesizer mounting brackets (3).

6. The multi-probe near-field electromagnetic characteristics testing system based on ultra-wideband plane wave synthesis method according to claim 1 is characterized in that: The angle between the ultra-wideband plane wave synthesizer (2) as a transmitting antenna and the ultra-wideband plane wave synthesizer (2) as a receiving antenna and the measured object (5) is θ, 0≤θ≤180°.

7. The multi-probe near-field electromagnetic characteristics test system based on ultra-wideband plane wave synthesis method according to claim 1, characterized in that: The system also includes a turntable (4), a control device and a test instrument (6), wherein the object to be tested (5) is mounted on the turntable (4), the control device is used to control the steering angle and steering speed of the turntable (4), and the control device controls the test instrument to generate a microwave signal and send it to an ultra-wideband plane wave synthesizer as a transmitting antenna; the ultra-wideband plane wave synthesizer as a receiving antenna receives the uniform plane wave reflected back by the object to be tested (5) and transmits it to the test instrument.

8. The multi-probe near-field electromagnetic characteristics testing system based on ultra-wideband plane wave synthesis method according to claim 7, characterized in that: Test instruments include vector network analyzers, spectrum analyzers, signal generators and power meters.

9. The multi-probe near-field electromagnetic characteristics testing system based on ultra-wideband plane wave synthesis method according to claim 1, characterized in that: The multiple ultra-wideband plane wave synthesizers include multiple tightly coupled antenna array modules (9) and multi-stage ultra-wideband power dividers (11), wherein the multiple tightly coupled antenna array modules (9) include M tightly arranged ultra-wideband antenna units (201), and the multi-stage ultra-wideband power dividers (11) realize equal-amplitude and in-phase power distribution of signals, and realize equal-amplitude and in-phase feeding of each ultra-wideband antenna unit (201) through an equal-amplitude and in-phase cable (10).

10. A method for testing a multi-probe near-field electromagnetic characteristics testing system based on an ultra-wideband plane wave synthesis method according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) The control device controls the object to be measured to be located at a predetermined distance, azimuth and elevation angle; (2) The control device controls the test instrument to generate a microwave signal, and the microwave signal passes through at least one ultra-wideband plane wave synthesizer and transmits a uniform plane wave through its corresponding transmitting plane wave probe; (3) After the uniform plane wave irradiates the object under test, the reflected signal of the object under test is received by at least one receiving plane wave probe and returned to the test instrument through its corresponding ultra-wideband plane wave synthesizer, thereby realizing dual-station or multi-station near-field electromagnetic characteristics testing; (4) Record relevant measured signals and data.

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