Large plane wave generator based on periodic rectangular reflector antenna array

Abstract

The invention provides a large plane wave generator based on a periodic rectangular reflector antenna array. The large plane wave generator comprises the periodic rectangular reflector antenna array, a rectangular reflector antenna array mounting bracket, N paths of equipower distribution networks, N amplitude-stable and phase-stable cables and a microwave signal source, the periodic rectangular reflector antenna array is vertically mounted on the rectangular reflector antenna array mounting bracket and is connected with the N amplitude-stabilized and phase-stabilized cables, the N amplitude-stabilized and phase-stabilized cables are connected with the N paths of equipower distribution networks, and the N paths of equipower distribution networks are connected with the microwave signal source. By optimizing the amplitude and phase distribution of the feed source array antenna, the equal electric field intensity and phase on the radiation aperture are realized, so that quasi-plane waves are formed on the radiation aperture of the rectangular reflector antenna unit. And the N rectangular reflector antenna units are periodically arranged, so that a large plane wave is formed on the radiation aperture of the periodic rectangular reflector antenna array.

Description

Technical Field

[0001] The invention relates to the technical field of microwave and wireless communication measurement, and in particular to a large plane wave generator based on a periodic rectangular reflector antenna array. Background Art

[0002] For the performance test of electrically large antennas, the test of electromagnetic scattering characteristics (RCS) of electrically large targets, and the over-the-air test (OTA) of electrically large wireless communication equipment, a large plane wave test electric field needs to be formed in order to simulate the incoming wave irradiating from the far field. At present, the methods for forming a plane wave test electric field mainly include the antenna far field method, the compact field method, and the array antenna plane wave conversion method. The antenna far field method is affected by the distance and cannot be implemented in a microwave darkroom space with limited distance; the compact field method requires a large-caliber metal reflector surface when realizing a large plane wave, and due to the deformation effect of the mechanical structure, the quality of the plane wave cannot be guaranteed. When designing a large plane wave, the array antenna plane wave conversion method is affected by the low aperture efficiency, the huge number of array elements, and the number of transceiver channels, and it cannot be implemented in engineering. Summary of the invention

[0003] Purpose of the invention: The technical problem to be solved by the present invention is to address the deficiencies in the prior art and to provide a large plane wave generator based on a periodic rectangular reflector antenna array. The large plane wave test electric field formed is used to perform radar scattering cross section, antenna performance or air interface performance tests on electrically large scattering targets, electrically large antennas or electrically large wireless communication products.

[0004] The invention specifically comprises a periodic rectangular reflector antenna array, a rectangular reflector antenna array mounting bracket, an N-way equal power distribution network, N amplitude-stabilized and phase-stabilized cables and a microwave signal source.

[0005] The periodic rectangular reflector antenna array is vertically mounted on a rectangular reflector antenna array mounting bracket and connected to N amplitude-stabilizing and phase-stabilizing cables, which are connected to N equal-power distribution networks, which are connected to a microwave signal source.

[0006] The periodic rectangular reflector antenna array is composed of N rectangular reflector antenna units arranged periodically.

[0007] The rectangular reflector antenna unit comprises a rectangular metal reflector, a feed array antenna and a feed array antenna bracket.

[0008] The feed array antenna is composed of M feed array antenna units arranged in a rectangular shape.

[0009] The feed array antenna is installed on the top of the rectangular metal reflective surface through a feed array antenna bracket, and the radiation direction is aligned with the center normal of the rectangular metal reflective surface.

[0010] The feed array antenna is connected to an amplitude- and phase-stabilizing cable.

[0011] A rectangular reflector antenna unit is designed under the set periodic boundary conditions, an electric field observation point is set on the radiation aperture surface of the rectangular reflector antenna unit, and a constrained optimization algorithm is used to calculate the excitation distribution of the feed array antenna so that the electric field intensity and phase angle at the observation point are equal.

[0012] The constrained optimization algorithm is a maximum power transmission method under constraints, and the formula is: , Among them, Max means finding the maximum value of the main function. The physical meaning of the main function is the sum of the electric field power density of the observation points. ST represents the constraint condition, C is a constant, and M is the number of electric field observation points set. The electric field values ​​of p observation points set on the radiation aperture surface of the rectangular reflector antenna unit, Represents the dielectric constant of air. The extreme value of the main function is obtained, and the power density of each electric field observation point is constrained to be equal, indicating that the energy radiated by the rectangular reflector antenna unit is maximized and evenly distributed on its radiation aperture surface, thus forming a plane wave.

[0013] The rectangular metal reflective surface is generated by rotating a parabola based on the normal direction of the center of the reflective surface to generate a circular reflective surface, and then performing rectangular cutting to generate the circular reflective surface.

[0014] The feed array antenna is composed of 4×4 feed array antenna units arranged in a half-wavelength period in the horizontal direction (X axis) and the vertical direction (Y axis).

[0015] The excitation distribution of the feed array antenna is realized by a fixed feeding network or an adjustable transceiver component; the fixed feeding network divides the feed line signal from the rectangular reflector antenna unit into 16 paths according to amplitude and phase distribution, and transmits them to the 16 feed array antenna units respectively; the adjustable transceiver component divides the feed signal into 16 paths, and transmits them to the 16 feed array antennas respectively through phase shifters, attenuators and amplifiers on 16 branches (the branches are structures on the fixed feeding network, which divide one excitation signal into 16 paths according to excitation distribution conditions, and respectively excite the 16 feed array antenna units); the amplitude and phase outputs of the fixed feeding network meet the excitation distribution requirements of the optimized designed feed array antenna.

[0016] The microwave signal source generates a microwave signal of a specific frequency, and the microwave signal is transmitted to N rectangular reflector antenna units through N equal power distribution networks and N amplitude-stabilized and phase-stabilized cables for simultaneous feeding, and finally forms a large plane wave on the radiation aperture surface of the periodic rectangular reflector antenna array.

[0017] The size of the rectangular metal reflective surface is much larger than the feed array antenna to reduce the shielding effect of the feed array antenna on the reflected wave, for example, a ratio of more than 10 times.

[0018] When the periodic rectangular reflector antenna array is designed to work at 2 GHz, the size of a single feed array antenna is 0.3 m × 0.3 m, and the size of a single rectangular metal reflector is 3.5 m × 3.5 m.

[0019] The distance from the feed array antenna to the rectangular metal reflective surface is much greater than the antenna wavelength, for example, more than 10 times; when the operating frequency of the feed array antenna is 2 GHz, the typical distance from the feed array antenna to the rectangular metal reflective surface is 2.5 m.

[0020] The value of N is greater than or equal to 9, so that at least one rectangular reflector antenna unit meets the quasi-periodic boundary conditions ("quasi" means "close to", the 9 units can be arranged in 3*3 in the X-axis and Y-axis directions, and the number of repetitions on each axis is only 3, and no standard period is formed (generally the number of units for the standard period is 5 or more), so it is called "quasi-periodic"), thereby forming a quasi-large plane wave on the aperture of the reflector antenna array.

[0021] When the feeding network is a fixed feeding network, it includes a microstrip power divider and a phase shifter.

[0022] By using more than 9 rectangular reflector antenna units for periodic arrangement, the large plane wave aperture size formed can reach the order of 10m.

[0023] The beneficial effects of the present invention are as follows: the present invention proposes a large plane wave generator based on a periodic rectangular reflector antenna array, wherein the periodic rectangular reflector antenna array is composed of N rectangular reflector antenna units arranged periodically, each rectangular reflector antenna unit is designed under periodic boundary conditions, and the electric field intensity and phase on the radiation aperture are equal by optimizing the amplitude and phase distribution of its feed array antenna, thereby forming a quasi-plane wave on the radiation aperture of the rectangular reflector antenna unit. Then, the N rectangular reflector antenna units are arranged periodically, thereby forming a large plane wave on the radiation aperture of the periodic rectangular reflector antenna array. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of a large plane wave generator based on a periodic rectangular reflector antenna array according to an embodiment of the present invention.

[0025] Figure 2 It is a rectangular reflector antenna unit under periodic boundary conditions of an embodiment of the present invention.

[0026] Figure 3It is a schematic diagram of the structure of the feed array antenna of the rectangular reflector antenna unit according to an embodiment of the present invention.

[0027] Figure 4 It is the optimization result of the electric field distribution on the radiation aperture surface of the rectangular reflector antenna unit in the embodiment of the present invention.

[0028] Figure 5 This is an optimization result (3D perspective) of the electric field distribution on the radiation aperture plane of the periodic rectangular reflector antenna array according to an embodiment of the present invention.

[0029] Figure 6 It is the optimization result of the electric field distribution on the radiation aperture plane of the periodic rectangular reflector antenna array according to the embodiment of the present invention (top view).

[0030] Figure 7 It is the electric field amplitude ripple on the X-axis at the center of the radiation aperture surface of the periodic rectangular reflector antenna array in the embodiment of the present invention.

[0031] Figure 8 It is the electric field phase ripple on the X-axis at the center of the radiation aperture surface of the periodic rectangular reflector antenna array in an embodiment of the present invention.

[0032] Fig. 9 It is the electric field amplitude ripple on the Y-axis at the center of the radiation aperture surface of the periodic rectangular reflector antenna array in the embodiment of the present invention.

[0033] Fig.10 It is the electric field phase ripple on the Y-axis at the center of the radiation aperture surface of the periodic rectangular reflector antenna array in an embodiment of the present invention.

[0034] Fig.11 It is a schematic diagram of a single rectangular reflector antenna unit.

[0035] Description of reference numerals:

[0036] 1. Radiating aperture surface of periodic rectangular reflector antenna array; 2. Periodic rectangular reflector antenna array; 3. Mounting bracket of rectangular reflector antenna array; 4. N amplitude-stabilized and phase-stabilized cables; 5. N-way equal power distribution network; 6. Microwave signal source; 7. Feed array antenna; 8. Feed array antenna bracket; 9. Rectangular metal reflector; 10. Radiating aperture surface of rectangular reflector antenna unit; 11. Periodic boundary of rectangular reflector antenna unit; 12. Mounting hole of feed array antenna bracket; 13. Coaxial feeding port; 14. Feed array antenna unit; 15. Fixed feeding network. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0038] An embodiment of the present invention provides a large plane wave generator based on a periodic rectangular reflector antenna array, including a periodic rectangular reflector antenna array 2, a rectangular reflector antenna array mounting bracket 3, an N-way equal power distribution network 5, N amplitude-stabilized and phase-stabilized cables 4 and a microwave signal source 6.

[0039] The periodic rectangular reflector antenna array 2 is vertically mounted on a rectangular reflector antenna array mounting bracket 3 and connected to N amplitude-stabilizing and phase-stabilizing cables 4, the N amplitude-stabilizing and phase-stabilizing cables 4 are connected to N-way equal power distribution networks 5, and the N-way equal power distribution networks 5 are connected to a microwave signal source 6.

[0040] The periodic rectangular reflector antenna array 2 is composed of N rectangular reflector antenna units arranged periodically.

[0041] The number of rectangular reflector antenna units of the periodic rectangular reflector antenna array 2 can be set to 9, which are periodically arranged in the X and Y axis directions as follows: Figure 1 shown.

[0042] In this embodiment, the rectangular reflector antenna unit is composed of a feed array antenna 7, a feed array antenna bracket 8, and a rectangular metal reflector 9. Figure 2 , Fig.11 As shown, the rectangular reflector antenna unit is designed under the condition of the set rectangular reflector antenna unit periodic boundary 11. By optimizing the amplitude and phase distribution of the feed array antenna, a quasi-plane wave is formed on the rectangular reflector antenna unit radiation aperture surface 10. Specifically, a number of electric field observation points are set on the rectangular reflector antenna unit radiation aperture surface 10, and the constrained optimization algorithm is used to calculate the excitation distribution of the feed array antenna so that the electric field intensity and phase angle at the observation point are equal. A fixed feeding network is used to distribute the feed signal power from the amplitude-stabilized and phase-stabilized cable into 16 paths to transmit to 16 feed array antenna units 14. The amplitude and phase outputs of the fixed feeding network meet the excitation distribution of the optimized designed feed array antenna.

[0043] In this embodiment, nine rectangular reflector antenna units are periodically arranged to form a periodic rectangular reflector antenna array 2. Figure 1 The microwave signal source 6 continuously generates a signal with a specific frequency of 2 GHz, which is stably transmitted to each periodic rectangular reflector antenna array 2 through an N-way equal power distribution network 5 and a stable amplitude and phase cable for feeding, and finally forms a large plane wave on the radiation aperture surface 1 of the periodic rectangular reflector antenna array.

[0044] In this embodiment, the feed array antenna of the rectangular reflector antenna unit is as follows: Figure 3As shown, the antenna array is composed of 4×4 feed array antenna units 14, a fixed feed network 15, a coaxial feed port 13, and a feed array antenna bracket mounting hole 12. The feed array antenna bracket mounting hole 12 is connected to the feed array antenna bracket 8 and fixed on the rectangular metal reflective surface 9. In addition, the optimal excitation distribution signal obtained by the optimization algorithm enters the feed array antenna through the coaxial feed port 13, and then transmits the signal to each feed array antenna unit 14 through the fixed feed network 15.

[0045] In this embodiment, a rectangular reflector antenna unit operating at 2 GHz is designed, such as Figure 2 As shown, the size of the rectangular metal reflector 9 is 3.5m×3.5m, the size of the feed array antenna 7 is 0.3m×0.3m, and the distance from the feed array antenna 7 to the rectangular metal reflector 9 is 2.5m. The commercial electromagnetic simulation software is used for structural modeling, and electromagnetic simulation is performed after setting periodic boundary conditions in the X and Y axis directions. At the same time, several observation points are set on the rectangular reflector antenna unit radiation aperture surface 10, and the amplitude and phase distribution of the feed array antenna are optimized using the constrained optimization algorithm. The electric field amplitude and phase of the observation point are uniformly distributed, thereby obtaining the optimal excitation distribution of the feed array antenna. A fixed feeding network 15 is designed based on the optimal excitation distribution of this feed array antenna, and the electric field distribution on the rectangular reflector unit radiation aperture surface under the periodic boundary 11 condition of the rectangular reflector antenna unit is obtained.

[0046] Furthermore, 3×3 rectangular reflector antenna units are periodically arranged into a rectangular reflector antenna array, such as Figure 1 The size of the rectangular reflector antenna array is 10.5m×10.5m. The microwave signal generated by the microwave signal source 6 is transmitted to the 9 rectangular reflector antenna units through 9 equal power distributors and 9 amplitude and phase stabilized cables, thereby obtaining the electric field distribution on the radiation aperture surface 1 of the 3×3 periodic rectangular reflector antenna array.

[0047] Figure 6 It is the electric field distribution vector diagram of the periodic rectangular metal reflector antenna array on the radiation aperture surface. The observation size of the radiation aperture surface is 10.5m×10.5m, the size of the large plane wave formed is 10m×10m, and the aperture efficiency of the generated plane wave is 91%.

[0048] Figure 7 It is the electric field amplitude ripple of the periodic rectangular metal reflector antenna array on the X-axis at the center of the radiation aperture surface. The amplitude ripple in the 10m observation area is less than 1dB.

[0049] Figure 8It is the electric field phase ripple of the periodic rectangular metal reflector antenna array on the X-axis at the center of the radiation aperture surface. The amplitude ripple in the 10m observation area is less than 3 degrees.

[0050] Fig. 9 It is the electric field amplitude ripple of the periodic rectangular metal reflector antenna array on the Y-axis at the center of the radiation aperture surface. The amplitude ripple in the 10m observation area is less than 1dB.

[0051] Fig.10 It is the electric field phase ripple of the periodic rectangular metal reflector antenna array on the Y-axis at the center of the radiation aperture surface. The amplitude ripple in the 10m observation area is less than 3 degrees.

[0052] In summary, the 3×3 periodic rectangular reflector antenna array realizes a large-scale plane wave of the order of 10m.

[0053] The present invention provides a large plane wave generator based on a periodic rectangular reflector antenna array. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A large plane wave generator based on a periodic rectangular reflector antenna array, characterized in that: It includes a periodic rectangular reflector antenna array, a rectangular reflector antenna array mounting bracket, an N-way equal power distribution network, N amplitude-stabilized and phase-stabilized cables and a microwave signal source; The periodic rectangular reflector antenna array is vertically mounted on a rectangular reflector antenna array mounting bracket and connected to N amplitude-stabilizing and phase-stabilizing cables, which are connected to N equal-power distribution networks, which are connected to a microwave signal source.

2. A large plane wave generator based on a periodic rectangular reflector antenna array as claimed in claim 1, characterized in that: The periodic rectangular reflector antenna array is composed of N rectangular reflector antenna units arranged periodically; The rectangular reflector antenna unit comprises a rectangular metal reflector, a feed array antenna and a feed array antenna bracket; The feed array antenna is composed of M feed array antenna units arranged in a rectangular shape; The feed array antenna is installed on the top of the rectangular metal reflective surface through the feed array antenna bracket, and the radiation direction is aligned with the center normal of the rectangular metal reflective surface; The feed array antenna is connected to an amplitude- and phase-stabilizing cable.

3. A large plane wave generator based on a periodic rectangular reflector antenna array as claimed in claim 2, characterized in that: Under the set periodic boundary conditions, a rectangular reflector antenna unit is designed, an electric field observation point is set on the radiation aperture surface of the rectangular reflector antenna unit, and a constrained optimization algorithm is used to calculate the excitation distribution of the feed array antenna so that the electric field intensity and phase angle at the observation point are equal; The constrained optimization algorithm is a maximum power transmission method under constraints, and the formula is: ， Among them, Max means finding the maximum value, ST means the constraint condition, C is a constant, and M is the number of electric field observation points set. The electric field values ​​of p observation points set on the radiation aperture surface of the rectangular reflector antenna unit, Represents the dielectric constant of air.

4. A large plane wave generator based on a periodic rectangular reflector antenna array as claimed in claim 3, characterized in that: The rectangular metal reflective surface is generated by rotating a parabola based on the normal direction of the center of the reflective surface to generate a circular reflective surface, and then performing rectangular cutting to generate the circular reflective surface.

5. A large plane wave generator based on a periodic rectangular reflector antenna array as claimed in claim 4, characterized in that: The feed array antenna is composed of 4×4 feed array antenna units arranged in a half-wavelength period in the horizontal direction and the vertical direction.

6. A large plane wave generator based on a periodic rectangular reflector antenna array as claimed in claim 5, characterized in that: The excitation distribution of the feed array antenna is realized by a fixed feed network or an adjustable transceiver component; the fixed feed network divides the feed line signal from the rectangular reflector antenna unit into 16 paths according to the amplitude and phase distribution, and transmits them to the 16 feed array antenna units respectively; the adjustable transceiver component divides the feed signal into 16 paths, and transmits them to the 16 feed array antennas respectively through the phase shifters, attenuators and amplifiers on the 16 branches; The amplitude and phase outputs of the fixed feed network meet the excitation distribution requirements of the optimally designed feed array antenna.

7. A large plane wave generator based on a periodic rectangular reflector antenna array as claimed in claim 6, characterized in that: The microwave signal source generates a microwave signal, which is transmitted to N rectangular reflector antenna units through N equal power distribution networks and N amplitude and phase stabilized cables for simultaneous feeding, and finally forms a large plane wave on the radiation aperture surface of the periodic rectangular reflector antenna array.

8. A large plane wave generator based on a periodic rectangular reflector antenna array as claimed in claim 7, characterized in that: The size of the rectangular metal reflective surface is larger than the feed array antenna.

9. A large plane wave generator based on a periodic rectangular reflector antenna array as claimed in claim 8, characterized in that: The distance between the feed array antenna and the rectangular metal reflective surface is greater than the antenna wavelength; The value of N is greater than or equal to 9, so that at least one rectangular reflector antenna unit satisfies the quasi-periodic boundary condition, thereby forming a quasi-large plane wave on the aperture of the reflector antenna array.

10. A large plane wave generator based on a periodic rectangular reflector antenna array as claimed in claim 9, characterized in that: When the feeding network is a fixed feeding network, it includes a microstrip power divider and a phase shifter.

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