Modular reflector array ultra wide band plane wave synthesis system

Abstract

The invention discloses a modularized reflector array ultra-wideband plane wave synthesis system. The system comprises a microwave darkroom, a feed source array and a reflector array, wherein the feed source array and the reflector array are arranged in the microwave darkroom. The feed source array comprises N ultra-wideband feed source antennas, the N ultra-wideband feed source antenna units are arranged at equal intervals to form the feed source array, the main reflecting surface array is located in the middle of one side of the anechoic chamber, and the M main reflecting surface units are tightly arranged to form the main reflecting surface array. The plane waves formed by the M main reflecting surface units are synthesized into large-size plane waves, and a large-size measurement quiet zone is formed. According to the invention, a complex antenna array feed network is reduced, the insertion loss is greatly reduced, the system complexity is reduced, amplitude-phase errors caused by factors such as manufacturing processes and installation processes of a power division PCB and an independent power division PCB are eliminated, and the antenna has the advantages of high aperture utilization rate, low processing difficulty of a reflecting surface, low manufacturing cost and the like; the method is especially suitable for measurement of large-size targets.

Description

Technical Field

[0001] This invention relates to the field of antenna and electromagnetic characteristic testing technology, and in particular to a modular reflector array ultrawideband plane wave synthesis system. Background Technology

[0002] Compact field electromagnetic property measurement is the most common testing method in the field of microwave measurement, playing an irreplaceable role in both military and civilian electronic information fields. Among different compact field electromagnetic property testing systems, the reflective compact field is the most widely used type, which can be mainly divided into three forms according to the number of reflective surfaces: single reflective surface, double reflective surface, and multiple reflective surface.

[0003] Although compact field electromagnetic characteristic measurement systems can generate quasi-plane waves in a relatively small space, enabling indoor spaces to meet the far-field conditions for target measurement, the size of the quiet zone in a compact field is a crucial indicator of the system's performance. Due to the diffraction effect at the reflector edge, the aperture utilization rate of existing compact field systems is very low; the quiet zone size is typically only about 30%-50% of the reflector size. As the size of the target increases, the required quiet zone size also increases, forcing a significant increase in the aperture of the compact field reflector. This undoubtedly increases the difficulty of manufacturing and shaping large-aperture reflectors. Therefore, for large targets such as aircraft and ships, the development of large-aperture reflectors in compact field electromagnetic characteristic measurement systems has become a bottleneck restricting further expansion of the test quiet zone. Summary of the Invention

[0004] One object of the present invention is to provide a modular reflector array ultrawideband plane wave synthesis system, which can be applied to a target electromagnetic property testing system.

[0005] The present invention discloses a modular reflector array ultrawideband plane wave synthesis system, comprising: a microwave anechoic chamber 1, and a feed array 3 and a reflector array 4, both disposed within the microwave anechoic chamber 1. The microwave anechoic chamber 1 includes an electromagnetic shielding chamber and radio frequency absorbing material 2 located around its perimeter.

[0006] Optionally, the feed array 3 includes N ultra-wideband feed antenna elements 301, which are arranged at equal intervals to form the feed array. The N ultra-wideband feed antenna elements 301 can be arranged with reduced element spacing. l A tightly coupled ultrawideband array that achieves strong mutual coupling can also be a cell-spaced array. l Traditional array antennas with wavelengths greater than half the lowest wavelength can also have element spacing. lAn uncoupled antenna array equal to the width W of the main reflector element 401, wherein the feed array includes a linear array and a surface array.

[0007] Optionally, the reflective surface array 4 includes a single reflective surface array, a dual reflective surface array, or a triple reflective surface array. The reflective surface array includes at least a main reflective surface array. The main reflective surface array consists of M main reflective surface units 401, which are arranged closely together to form the main reflective surface array, used to form a test quiet zone. The values ​​of M and N can be different and are not fixed; they can be adjusted according to specific application scenarios and parameter requirements.

[0008] Optionally, the M main reflector units 401 include: multiple central main reflector units 4011 and edge main reflector units 4012; the edge main reflector units 4012 are located at the edge of the main reflector array, and their shapes are sawtooth, rolled edge, wave-absorbing, or high-resistivity metamaterials, etc., to increase the size of the test quiet zone. Optionally, the ultra-wideband electromagnetic waves generated by the feed array 3 are reflected by the sub-reflector units 402 and the main reflector units 401 to form plane waves. The plane waves formed by the M main reflector units 401 are combined into a large-size plane wave, forming a large-size measurement quiet zone.

[0009] Optionally, when the M main reflective surface units 401 are located at the edge of the main reflective surface array, their edge shape can adopt structures such as sawtooth, rolled edge, wave-absorbing and high-resistivity metamaterial to increase the size of the test quiet zone.

[0010] Optionally, the M main reflective surface units 401 are mounted on a modularly designed bracket 403. Each main reflective surface unit 401 has three or more module adjustment mechanisms 404. The front, back, left, and right positions of the main reflective surface unit 401 can be adjusted through the module adjustment mechanisms 404. The center of the M main reflective surface units 401 is on a plane.

[0011] Optionally, the main reflector array 4 is mounted on a modularly designed module mounting bracket 403, with the main reflector array 4 located in the middle of one side of the microwave anechoic chamber 1. The module mounting bracket 403 has three or more vertical adjustment mechanisms 405, which adjust the left and right tilt of the main reflector array by adjusting the vertical position of the vertical adjustment mechanisms 405.

[0012] Optionally, the feed array 3 is located outside the large-size measurement quiet zone 5 to reduce the obstruction of electromagnetic waves by the feed array 3.

[0013] Optionally, the main reflector element 401 can be in the form of a Cassegrain, Gregorian, or ring-focal antenna. The Cassegrain antenna includes a main reflector element 401 and a sub-reflector 402. The main reflector element 401 is a paraboloid of revolution, and the sub-reflector 402 is a hyperboloid of revolution. The Gregorian antenna includes a main reflector element and a sub-reflector. The main reflector is a paraboloid of revolution, and the sub-reflector is an ellipsoid of revolution.

[0014] To improve the aperture utilization rate of the compact field reflector, reduce the processing difficulty and manufacturing cost of the reflector, and increase the aperture size of the reflector, this invention discloses a modular reflector array ultra-wideband plane wave synthesis system that can be spliced ​​together. Based on this system, the target electromagnetic characteristic testing system can reduce the complexity of the antenna array feed network, significantly reduce insertion loss, reduce system complexity, and eliminate amplitude and phase errors caused by factors such as the manufacturing and installation processes of the power divider PCB board and independent power divider PCB boards. Compared with the compact field system, it has advantages such as high aperture utilization rate, low reflector processing difficulty, and low manufacturing cost, making it particularly suitable for the measurement of large-sized targets. This invention is suitable for indoor plane wave electromagnetic characteristic testing, especially for indoor measurement of large-sized targets.

[0015] The beneficial effects of this invention are as follows: 1. Compared with existing compact field testing technology, the significant technical effect of this invention is that by combining plane waves from multiple main reflector units, the quiet zone space is expanded, the aperture utilization rate of the reflector is improved, the processing difficulty of large-aperture reflectors is reduced, and the manufacturing cost is reduced; 2. Compared with existing plane wave synthesis testing technology, the significant technical effect of this invention is that by using open-interface feeding technology, the complex antenna array feeding network is reduced, the insertion loss is significantly reduced, the system complexity is reduced, and the amplitude and phase errors caused by factors such as the manufacturing process and installation process of the power divider PCB board and the independent power divider PCB board are eliminated, thereby improving the testing performance. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an ultrawideband plane wave synthesis system with a modular reflector array that can be spliced ​​together, according to an embodiment of the present invention. Figure 2 This is a schematic diagram of a three-reflector unit and a three-reflector array structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the main reflector element, sub-reflector element, and array structure of a Cassegrain antenna according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the main reflective surface array, module adjustment mechanism, module mounting bracket, and vertical position adjustment mechanism according to an embodiment of the present invention. Figure 5This is a schematic diagram of the structure of an ultrawideband plane wave synthesis system with a modular reflector array that can be spliced ​​together, according to an embodiment of the present invention. Figure 6 This is a schematic diagram of the edge sawtooth structure of the main reflective surface unit located at the edge of the main reflective surface array according to an embodiment of the present invention; Among them: 1- Microwave anechoic chamber, 2- Radio frequency absorbing material, 3- Feed array, 4- Reflector array, 5- Large-size measurement quiet zone, 301- Ultra-wideband feed antenna unit, 401- Main reflector unit, 402- Sub-reflector unit, 403- Module mounting bracket, 404- Module adjustment mechanism, 405- Up and down adjustment mechanism, 4011- Center main reflector unit, 4012- Edge main reflector unit. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be clearly and completely described below with reference to specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this application.

[0018] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0019] See Figure 1 This invention discloses a modular reflector array ultra-wideband plane wave synthesis method and a schematic diagram of a target electromagnetic characteristic testing system based on this method. It includes a microwave anechoic chamber 1 and a feed array 3 and a reflector array 4, both disposed within the microwave anechoic chamber. The feed array 3 comprises N ultra-wideband feed antenna elements 301, arranged at equal intervals to form a feed array, which includes linear and area arrays. The reflector array 4 includes single-reflector arrays, dual-reflector arrays, and triple-reflector arrays, etc. The reflector array includes at least a main reflector array, located in the middle of one side of the microwave anechoic chamber. The main reflector array consists of M main reflector elements 401, arranged closely together. The ultra-wideband electromagnetic waves generated by the feed array 3 pass through the main reflector elements 401 to form plane waves. The plane waves formed by the M main reflector elements are synthesized into a large-size plane wave 5, forming a large-size measurement quiet zone. The feed array 3 is located outside the large-size measurement quiet zone 5 and is located on one side of the microwave anechoic chamber 1, reducing the shielding of electromagnetic waves by the feed array 3.

[0020] See Figure 2This embodiment provides a schematic diagram of an optional three-reflector element and a three-reflector array structure. The ultra-wideband electromagnetic wave generated by the ultra-wideband feed antenna element 301 is reflected by the sub-reflector element 402 and the main reflector element 401 to form a plane wave. The plane waves formed by the M main reflector elements 401 are combined to form a large-size plane wave, creating a large-size measurement quiet zone. The N ultra-wideband feed antenna elements 301 are arranged at equal intervals to form a feed array. The N ultra-wideband feed antenna elements 301 can be arranged with reduced element spacing. l A tightly coupled ultrawideband array that achieves strong mutual coupling can also be a cell-spaced array. l Traditional array antennas with wavelengths greater than half the lowest wavelength can also have element spacing. l The feed array 3 is an uncoupled antenna array equal to the width W of the main reflector element 401, and includes a linear array and a surface array.

[0021] See Figure 3 This embodiment provides a schematic diagram of the main reflector element and sub-reflector element of the Cassegrain-type antenna according to the present invention, and their array structure. The Cassegrain-type antenna element includes a main reflector element 401 and a sub-reflector element 402. The main reflector element 401 is a paraboloid of revolution, and the sub-reflector element 402 is a hyperboloid of revolution. The plane waves generated by the M main reflector elements 401 are combined into a large-size plane wave, forming a large-size measurement quiet zone. Figure 3 As shown, the ultra-wideband feed antenna element 301 can be located at the center of the main reflector element 401, directly facing the sub-reflector 402, while the sub-reflector 402 is located at the focal point of the main reflector element 401.

[0022] See Figure 4 This embodiment provides a schematic diagram of the main reflective surface array, module adjustment mechanism, module mounting bracket, and vertical position adjustment mechanism of the present invention. The M main reflective surface units 401 are mounted on the module mounting bracket 403. Each main reflective surface unit 401 has three or more module adjustment mechanisms 404. These mechanisms allow adjustment of the front-back, rear-side, left-side, and right-side positions of the main reflective surface unit 401, ensuring that the center of the M main reflective surface units 401 is on a single plane. The main reflective surface array 4 is located in the middle of one side of the microwave anechoic chamber 1. The module mounting bracket 403 has three or more vertical adjustment mechanisms 405, which adjust the left-right tilt of the main reflective surface array by adjusting their positions.

[0023] See Figure 5This invention discloses another modular reflector array ultra-wideband plane wave synthesis method, and a schematic diagram of a target electromagnetic characteristic testing system based on this method. It includes: a microwave anechoic chamber 1, and a feed array 3 and a reflector array 4, both disposed within the microwave anechoic chamber. The feed array 3 comprises N ultra-wideband feed antenna elements 301, arranged at equal intervals to form a feed array. The feed array 3 includes either a linear array or a surface array. The reflector array 4 includes a single reflector array, a dual reflector array, or a triple reflector array, etc. The reflector array includes at least a main reflector array, located in the middle of one side of the microwave anechoic chamber. The main reflector array consists of M main reflector elements 401, arranged closely together. The ultra-wideband electromagnetic waves generated by the feed array 3 pass through the main reflector elements 401 to form plane waves. The plane waves formed by the M main reflector elements are synthesized into a large-size plane wave 5, forming a large-size measurement quiet zone. The feed array 3 is located outside the large-size measurement quiet zone 5, and the feed array 3 is located on both sides of the microwave anechoic chamber 1 to reduce the shielding of electromagnetic waves by the feed array 3.

[0024] See Figure 6 This invention provides a schematic diagram of an optional sawtooth structure for a main reflective surface unit located at the edge of the main reflective surface array. The main reflective surface unit 401 includes a central main reflective surface unit 4011 and an edge main reflective surface unit 4012. Figure 6 The image shown is a partial view of the upper left corner of the entire array. The element with spikes along its edge is the edge primary reflector unit 4012, while the central primary reflector unit 4011 has no spikes. The edge primary reflector unit 4012 is located at the edge of the primary reflector array, and its edge shape can adopt a serrated structure to increase the size of the test quiet zone.

[0025] This invention reduces the complexity of the antenna array feed network, significantly reduces insertion loss, reduces system complexity, and eliminates amplitude and phase errors caused by factors such as the manufacturing and installation processes of the power divider PCB board and independent power divider PCB board. It has advantages such as high aperture utilization, low difficulty in processing the reflector surface, and low manufacturing cost, and is particularly suitable for the measurement of large-size targets.

Claims

1. A modular reflector array ultra-wideband plane wave synthesis system, characterized by The utility model relates to a microwave anechoic chamber, and microwave anechoic chamber comprises: Microwave anechoic chamber (1), the microwave anechoic chamber (1) includes electromagnetic shield body anechoic chamber and radio frequency wave absorbing material (2) in the four perimeter inner walls of electromagnetic shield body anechoic chamber; Feed array (3) and reflector array (4) are arranged in the microwave anechoic chamber (1); 2. The modular reflector array ultra-wideband planar wave synthesis system of claim 1, wherein, N ultra-wideband feed antenna units (301) are arranged equidistantly to form a feed array, the N ultra-wideband feed antenna units (301) are arranged with a unit spacing l a tightly coupled ultra-wideband array realizing strong mutual coupling effect or a unit spacing l an array antenna with a unit spacing greater than one half of the minimum wavelength l a non-coupled antenna array with a unit spacing equal to the width W of the main reflector The feed array (3) comprises a linear array or a planar array.

3. The modular reflector array ultra-wideband planar wave hybrid system of claim 2, wherein, The reflector array (4) comprises a single reflector array, a double reflector array or a triple reflector array. The reflector array (4) comprises at least a main reflector array, and the main reflector array comprises M main reflector units (401) arranged closely to form the main reflector array (4), and the main reflector array is used for forming a test quiet zone.

4. The modular reflector array ultra-wideband planar wave hybrid system of claim 3, wherein, The M main reflector units (401) comprise a plurality of central main reflector units (4011) and edge main reflector units (4012), and the edge main reflector units (4012) are located at the edges of the main reflector array, and the edge main reflector units (4012) are in the form of structures such as sawtooth, hem, wave absorbing or high-resistance super material, so as to improve the size of the test quiet zone.

5. The modular reflector array ultra-wideband planar wave synthesis system of claim 3, wherein, The ultra-wideband electromagnetic waves generated by the feed array (3) are reflected by the auxiliary reflector units (402) and / or the main reflector units (401) to form plane waves, the plane waves formed by the M main reflector units (401) are combined into large-size plane waves, and a large-size measurement quiet zone (5) is formed.

6. The modular reflector array ultra-wideband planar wave synthesis system of claim 3, wherein, The M main reflector units (401) are installed on a modularly designed module mounting support (403), and more than three module adjusting mechanisms (404) are arranged on each main reflector unit (401), the front, rear, left and right positions of the main reflector unit (401) are adjusted through the module adjusting mechanisms (404), and the positions of the M main reflector units (401) are centered on a plane.

7. The modular reflector array ultra-wideband planar wave synthesis system of claim 1, wherein, The main reflector array (4) is installed on a modularly designed module mounting support (403), and the main reflector array (4) is located at the middle position of one side of the microwave anechoic chamber (1); more than three up-down adjusting mechanisms (405) are arranged on the module mounting support (403), and the left and right inclinations of the main reflector array are adjusted by adjusting the up-down positions of the up-down adjusting mechanisms (405).

8. The modular reflector array ultra-wideband planar wave synthesis system of claim 5, wherein, The feed array (3) is located outside the large-size measurement quiet zone (5), and the feed array (3) is located on one side or both sides or all around of the microwave anechoic chamber (1), so as to reduce the shielding of the electromagnetic waves by the feed array (3).

9. The modular reflector array ultra-wideband planar wave synthesis system of claim 1, wherein, The feed array (3) and the main reflector unit (401) adopt the form of Cassegrain antenna, Gregorian antenna or ring focus antenna, the Cassegrain antenna comprises a main reflector unit (401) and a sub-reflector (402), wherein the main reflector unit (401) is a rotating paraboloid, and the sub-reflector (402) is a rotating hyperboloid; the Gregorian antenna comprises a main reflector unit and a sub-reflector, the main reflector is a rotating paraboloid, and the sub-reflector is a rotating ellipsoid. For example, the ultra-wideband feed antenna unit (301) emits electromagnetic waves to first enter the sub-reflector (402), is reflected to the main reflector unit (401) by the sub-reflector (402), and finally forms a plane wave on the main reflector unit (401) to be transmitted to the free space.

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