A large-inter-space subarray phased array system based on a codeable metasurface

Abstract

The application discloses a large-interval subarray phased array system based on a codeable metasurface, a codeable metasurface module, a phased array antenna module, a receiving and transmitting path module and a beam control and forming module; the codeable metasurface module is arranged above the phased array antenna module, the codeable metasurface module is in communication connection with the beam control and forming module; the phased array antenna module is in communication connection with the beam control and forming module through the receiving and transmitting path module; wherein the beam control and forming module is used for controlling the phased array antenna module to perform beam scanning; and when each wave position of the phased array antenna module is generated, the beam control and forming module is also used for controlling the codeable metasurface module to generate a corresponding compensation phase. The application can effectively suppress the scanning grating lobes of the large-interval subarray.

Description

Technical Field

[0001] The present invention relates to the technical field of phased array antennas, and in particular to a large-spacing sub-array phased array system based on a codable metasurface. Background Art

[0002] Phased array antennas are widely used in radar and communication systems. Compared with traditional mechanical scanning antennas, they have the significant advantage of flexible and fast beam scanning.

[0003] To improve antenna resolution, phased array antennas require larger apertures. In engineering, the most common approach to reducing the number of transmit and receive paths and lowering radar array costs is to divide the array into subarrays, with antenna elements within each subarray sharing the same transmit and receive channels. While simple and effective, this approach significantly increases the distance between subarrays, even exceeding the operating wavelength. This can cause grating lobes to appear in the array's radiation pattern, degrading the system's power and anti-interference characteristics.

[0004] At present, there are two commonly used methods at home and abroad to suppress grating lobes in phased arrays with large sub-array spacing: one is to adopt a sub-array-level aperiodic array method to make the phase center of the sub-array exhibit aperiodic characteristics to suppress grating lobes, such as sub-array rotation, sub-array staggering, sub-array splicing, and sparse sub-arrays; the other method is to optimize the antenna unit radiation pattern to achieve the effect of array grating lobe suppression, but this method has strong limitations and the suppression effect is general. Summary of the Invention

[0005] In order to solve the technical problems existing in the background technology, the present invention proposes a large-pitch sub-array phased array system based on a codable metasurface.

[0006] The present invention proposes a large-pitch sub-array phased array system based on a codeable metasurface, comprising: a codeable metasurface module, a phased array antenna module, a receiving and transmitting path module, and a beam control and forming module;

[0007] The codeable metasurface module is arranged above the phased array antenna module, and the codeable metasurface module is communicatively connected to the beam control and forming module; the phased array antenna module is communicatively connected to the beam control and forming module through the receiving and transmitting path modules;

[0008] Among them, the beam control and forming module is used to control the phased array antenna module to perform beam scanning;

[0009] It is also used to control the codable metasurface module to generate a corresponding compensation phase every time the phased array antenna module generates a wave position.

[0010] Preferably, the encodable metasurface module comprises M×N metasurface units, and each of the metasurface units is connected to the beam control and forming module.

[0011] Preferably, the encodable metasurface module includes 16×16 metasurface units.

[0012] Preferably, each metasurface unit is independently controlled.

[0013] Preferably, the phased array antenna module includes m antenna subarrays arranged periodically, each antenna subarray includes n antenna units and a power division feeding network, the n antenna units are respectively connected to the power division feeding network, and the power division feeding network is connected to the receiving and transmitting path modules.

[0014] Preferably, m is 16 and n is 16.

[0015] Preferably, the compensation phase can be generated according to the following formula:

[0016]

[0017] β′ pq =kid x u+kjd y v; where i = 1, 2, ..., m, j = 1, 2, ..., n;

[0018]

[0019] Where, is the phase distribution of the encodable metasurface module, β′ pq is the excitation phase of the antenna element in the phased array antenna module, β″ pq is for β′ pq Phase distribution after 4×4 antenna subarray division, that is, each 4×4 antenna subarray shares a phase, and the phase value is the average of the original 16 channel phase values; m is the number of antenna subarrays in the phased array antenna module, n is the number of antenna elements in each antenna subarray, k is the free space wave number, dx = dy = 10 mm, θ is the azimuth scanning angle of the phased array system, is the pitch scanning angle of the phased array system.

[0020] Preferably, the receiving and transmitting path module includes m receiving and transmitting paths, each receiving and transmitting path includes: a phase shifter, a transceiver switch, a power amplifier, a circulator, a filter and a low noise amplifier;

[0021] One end of the phase shifter is connected to the beam steering and forming module, and the other end is connected to the moving contact of the transceiver switch;

[0022] The first static contact of the transceiver switch is connected to one end of the power amplifier, and the other end of the power amplifier is connected to the first port of the circulator; the second static contact of the transceiver switch is connected to one end of the low-noise amplifier, and the other end of the low-noise amplifier is connected to one end of the filter, and the other end of the filter is connected to the second port of the circulator;

[0023] The third port of the circulator is used to connect to the power division feeding network of the corresponding antenna subarray.

[0024] The proposed large-pitch subarray phased array system based on a codeable metasurface effectively suppresses the scanning grating lobes of large-pitch subarrays by independently controlling the transmission phase of each metasurface unit in the codeable metasurface module to produce a specific phase distribution. Furthermore, compared with traditional large-pitch subarray phased array systems, the scanning performance of the entire system can be improved by simply adding independent metasurface modules, significantly reducing the number of channels and system costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic structural diagram of a large-pitch sub-array phased array system based on a codeable metasurface in one embodiment of the present invention.

[0026] Figure 2 Schematic diagram of sub-oscillator division of a phased array antenna module in an embodiment of the present invention.

[0027] Figure 3 Schematic diagram of the phase distribution of the encodable metasurface module at a typical scanning angle in one embodiment of the present invention.

[0028] Figure 4 Comparison of the far-field scanning directions of the traditional phased array system and the phased array system of the present invention Figure 1 .

[0029] Figure 5 Comparison of the far-field scanning directions of the traditional phased array system and the phased array system of the present invention Figure 2 . DETAILED DESCRIPTION

[0030] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0031] Reference Figure 1-3 The present invention proposes a large-pitch sub-array phased array system based on a codeable metasurface, comprising: a codeable metasurface module, a phased array antenna module, a receiving and transmitting path module, and a beam control and forming module.

[0032] The codeable metasurface module is arranged above the phased array antenna module, and the codeable metasurface module is communicatively connected with the beam control and forming module;

[0033] The phased array antenna module is communicatively connected to the beam control and forming module via the receiving and transmitting path modules;

[0034] The beam control and forming module is used to control the phased array antenna module to perform beam scanning;

[0035] Every time the phased array antenna module generates a wave position, it is also used to control the codable metasurface module to generate a corresponding compensation phase, thereby suppressing the generation of large-spacing scanning grating lobes.

[0036] When the present invention is implemented, the beam control and forming module is respectively communicated with the codable metasurface module and the phased array antenna module, so that the beam control and forming module can control the feeding phase and timing of each antenna subarray, and can also control the timing and coding of each unit of the codable metasurface, so that the beam control and forming module can control the phased array antenna module to perform beam scanning; and when the phased array antenna module generates a wave position each time, it is also used to control the codable metasurface module to generate a corresponding compensation phase, thereby suppressing the generation of large-spacing scanning grating lobes.

[0037] This invention independently controls the transmission phase of each metasurface unit in the codeable metasurface module to produce a specific phase distribution, effectively suppressing the scanning grating lobes of large-pitch subarrays. Furthermore, compared with traditional large-pitch phased array systems, the scanning performance of the entire system can be improved by simply adding independent metasurface modules, significantly reducing the number of channels and system costs.

[0038] In this embodiment, the encodable metasurface module includes M×N metasurface units, and each of the metasurface units is connected to the beam steering and forming module.

[0039] Each metasurface unit is independently controlled to facilitate independent regulation, thereby producing a specific phase distribution, thereby effectively suppressing the scanning grating lobes of large-pitch sub-arrays.

[0040] Specifically, each metasurface unit is connected to the beam steering and forming module through a control port.

[0041] It should be noted that the M metasurface units are arranged in an array, and each metasurface unit includes N metasurfaces.

[0042] In this embodiment, the phased array antenna module includes m antenna subarrays arranged periodically, each antenna subarray includes n antenna units and a power divider feed network, the n antenna units are respectively connected to the power divider feed network, and the power divider feed network is connected to the receiving and transmitting path modules.

[0043] In this embodiment, the receiving and transmitting path module includes m receiving and transmitting paths, each receiving and transmitting path includes: a phase shifter, a transceiver switch, a power amplifier, a circulator, a filter and a low noise amplifier;

[0044] One end of the phase shifter is connected to the beam steering and forming module, and the other end is connected to the moving contact of the transceiver switch;

[0045] The first static contact of the transceiver switch is connected to one end of the power amplifier, and the other end of the power amplifier is connected to the first port of the circulator; the second static contact of the transceiver switch is connected to one end of the low-noise amplifier, and the other end of the low-noise amplifier is connected to one end of the filter, and the other end of the filter is connected to the second port of the circulator;

[0046] The third port of the circulator is used to connect to the power division feeding network of the corresponding antenna subarray.

[0047] Example 1

[0048] This embodiment constructs a phased array system with 16×16 antenna units, where 4×4 antenna units form an antenna subarray, with a total of 16 antenna subarrays. Figure 2 The central operating frequency of the antenna unit is 10 GHz, the unit spacing along the x-axis and y-axis is 10 mm, and the antenna subarray is fed through a power division network.

[0049] The codeable metasurface module consists of 16×16 metasurface units, each of which has an independent control line. The transmission phase of the metasurface unit is controlled by the FPGA in the beam control and forming module. Multiple metasurface units are arranged in a one-to-one correspondence with multiple antenna subarrays. The metasurface unit in this embodiment uses a 3-bit codeable metasurface, which can generate 8 codes: 000, 001, 010, 011, 100, 101, 110, and 111, corresponding to 8 transmission phases of 0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°, and 360°, respectively.

[0050] According to the different beam scanning angles of the phased array system, the codeable metasurface module needs to generate different compensation phases. The generation of the compensation phase can be based on the following formula:

[0051]

[0052] β′ pq =kid x u+kjd y v; where i = 1, 2, ..., m, j = 1, 2, ..., n;

[0053]

[0054] Where m is the number of antenna subarrays in the phased array antenna module, and n is the number of antenna elements in each antenna subarray; is the phase distribution of the encodable metasurface module, β′ pq is the excitation phase of the antenna element in the phased array antenna module, β″ pq is for β′ pq Phase distribution after 4×4 antenna subarray division, that is, each 4×4 antenna subarray shares a phase, the phase value is the average of the original 16 channel phase values, k is the free space wave number, dx = dy = 10mm, θ is the azimuth scanning angle of the phased array system, is the pitch scanning angle of the phased array system.

[0055] The coding distribution of the encodable metasurface module in this embodiment at a typical scanning angle (30° for azimuth scanning and 60° for elevation scanning) is as follows: Figure 3 shown.

[0056] In order to fully illustrate the superiority of the phased array system of the present invention, the phased array system of this embodiment completes the azimuth ±60 degree scanning and the pitch ±45 degree scanning, and is compared with the traditional phased array system. The comparison results are as follows: Figure 4 and Figure 5 shown.

[0057] from Figure 4 and Figure 5 As can be seen from the figure, correcting the azimuth beam pointing from (-10°, 10°) to (-60°, 60°) improves grating lobe suppression by 12dB, and correcting the elevation beam pointing from (-5°, 5°) to (-45°, 45°) improves grating lobe suppression by 11dB. This demonstrates that the phased array system proposed in this invention can significantly reduce the grating lobe level in a phased array system with large-pitch subarrays, improving beam pointing accuracy.

[0058] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A large-pitch sub-array phased array system based on a codeable metasurface, characterized in that: include: Codable metasurface module, phased array antenna module, receive and transmit path module, and beam control and forming module; The codeable metasurface module is arranged above the phased array antenna module, and the codeable metasurface module is communicatively connected to the beam control and forming module; the phased array antenna module is communicatively connected to the beam control and forming module through the receiving and transmitting path modules; The beam control and forming module is used to control the phased array antenna module to perform beam scanning; and each time the phased array antenna module generates a wave position, it is also used to control the codeable metasurface module to generate a corresponding compensation phase; The compensation phase can be generated according to the following formula: Where, is the phase distribution of the encodable metasurface module, β′ pq It is the excitation phase of the antenna unit in the phased array antenna module, which is related to the azimuth scanning angle and elevation scanning angle of the phased array system; β″ pq is for β′ pq After the antenna subarray is divided into phase distributions, all antenna elements in each antenna subarray share a common phase. The phase value is the average of the original n channel phase values ​​of the antenna subarray, where n is the number of antenna elements in each antenna subarray.

2. The large-pitch sub-array phased array system based on a codeable metasurface according to claim 1, characterized in that: The codeable metasurface module contains M×N metasurface units, and each metasurface unit is connected to the beam control and forming module.

3. The large-pitch sub-array phased array system based on a codeable metasurface according to claim 2, characterized in that: The encodable metasurface module contains 16×16 metasurface units.

4. The large-pitch sub-array phased array system based on a codeable metasurface according to claim 2, characterized in that: Each metasurface unit is independently controlled.

5. The large-pitch sub-array phased array system based on a codeable metasurface according to claim 1, characterized in that: The phased array antenna module includes m antenna subarrays arranged periodically. Each antenna subarray includes n antenna units and a power divider feeding network. The n antenna units are respectively connected to the power divider feeding network, and the power divider feeding network is connected to the receiving and transmitting path modules.

6. The large-pitch sub-array phased array system based on a codeable metasurface according to claim 5, characterized in that: m is 16 and n is 16.

7. The large-pitch sub-array phased array system based on a codeable metasurface according to claim 1, characterized in that: β′ pq =kid x u+kjd y v; Where i = 1, 2..., m, j = 1, 2..., n, m is the number of antenna subarrays in the phased array antenna module, n is the number of antenna elements in each antenna subarray, k is the free space wave number, dx = dy = 10 mm, θ is the azimuth scanning angle of the phased array system, is the pitch scanning angle of the phased array system.

8. The large-pitch sub-array phased array system based on a codeable metasurface according to claim 5, characterized in that: The receiving and transmitting path module includes m receiving and transmitting paths, each receiving and transmitting path includes: a phase shifter, a transceiver switch, a power amplifier, a circulator, a filter and a low noise amplifier; One end of the phase shifter is connected to the beam steering and forming module, and the other end is connected to the moving contact of the transceiver switch; The first static contact of the transceiver switch is connected to one end of the power amplifier, and the other end of the power amplifier is connected to the first port of the circulator; the second static contact of the transceiver switch is connected to one end of the low-noise amplifier, and the other end of the low-noise amplifier is connected to one end of the filter, and the other end of the filter is connected to the second port of the circulator; The third port of the circulator is used to connect to the power division feeding network of the corresponding antenna subarray.

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