Large-spacing subarray phased array system based on encodable metasurface

Abstract

The invention discloses a large-spacing subarray phased array system based on a coding metasurface. The large-spacing subarray phased array system comprises a coding metasurface module, a phased array antenna module, a receiving and transmitting path module and a beam control and formation module, the encodable metasurface module is arranged above the phased-array antenna module, and the encodable metasurface is in communication connection with the beam control and formation module; the phased-array antenna module is in communication connection with the beam control and formation module through the receiving and transmitting path module; wherein the beam control and formation module is used for controlling the phased-array antenna module to perform beam scanning; and when the phased-array antenna module generates one wave position, the phased-array antenna module is also used for controlling the encodable metasurface module to generate a corresponding compensation phase. According to the invention, the scanning grating lobe of the large-spacing subarray can be effectively suppressed.

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 significant advantages in flexible and fast beam scanning.

[0003] In order to improve antenna resolution, phased array antennas require a larger aperture area. In order to reduce the number of transmit and receive channels and reduce the cost of the radar array, the most commonly used method in engineering is to divide the array into sub-arrays, where the antenna units share the transmit and receive channels. Although this method is simple and effective, it will greatly increase the distance between the sub-arrays, even far exceeding the working wavelength, causing grating lobes to appear in the array radiation pattern, deteriorating the power characteristics and anti-interference characteristics of the system.

[0004] At present, there are two commonly used methods to suppress the grating lobes of phased arrays with large spacing of sub-arrays at home and abroad: one is to adopt a sub-array-level non-periodic array arrangement to make the phase center of the sub-array present a non-periodic characteristic to suppress the grating lobes, such as sub-array rotation, sub-array misalignment, 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 is communicatively connected with the beam control and forming module; the phased array antenna module is communicatively connected with the beam control and forming module through the receiving and transmitting path module;

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

[0009] 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.

[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 comprises 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 may be generated according to the following formula:

[0016]

[0017] β p ' q =kmd x u+knd y v(m=1,2...16,n=1,2...16);

[0018]

[0019] In the formula, is the phase distribution of the encodable metasurface module, β p ' q is the excitation phase of the antenna unit of the single-channel phased array system, β p ″ q is for β p ' q 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 elevation 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 control 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 sub-oscillator.

[0024] In the present invention, the proposed large-pitch sub-array phased array system based on a coded metasurface produces a specific phase distribution by independently regulating the transmission phase of each metasurface unit in the coded metasurface module, thereby effectively suppressing the scanning grating lobe of the large-pitch sub-array. Moreover, compared with the traditional large-pitch sub-array phased array system, only an independent metasurface module needs to be added to improve the scanning performance of the entire system, which greatly saves the number of channels and reduces the system cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the structure of a large-pitch sub-array phased array system based on a codable metasurface in one embodiment of the present invention.

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

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

[0028] Figure 4 Comparison of the far-field scanning directions of the conventional 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 conventional 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 of the present invention and the features in the embodiments 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 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 through 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] The present invention produces a specific phase distribution by independently regulating the transmission phase of each metasurface unit in the coded metasurface module, thereby effectively suppressing the scanning grating lobe of the large-pitch subarray. Moreover, compared with the traditional large-pitch subarray phased array system, only an independent metasurface module needs to be added to improve the scanning performance of the entire system, which greatly saves the number of channels and reduces the system cost.

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

[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 control 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 sub-oscillator.

[0047] Embodiment 1

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

[0049] The encodable metasurface module is composed of 16×16 metasurface units, each of which has an independent control line, and 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 sub-oscillators. The metasurface unit in this embodiment adopts a 3-bit encodable metasurface, which can generate 8 codes of 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 encodable metasurface module needs to generate different compensation phases. The generation of the compensation phase can be based on the following formula:

[0051]

[0052] β p ' q =kmd x u+knd y v(m=1,2...16,n=1,2...16);

[0053]

[0054] In the formula, is the phase distribution of the encodable metasurface module, β p ' q is the excitation phase of the antenna unit of the single-channel phased array system, β p ″ q is for β p ' q 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 elevation 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 respectively, 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 It can be seen that the grating lobe level suppression is improved by 12dB when the azimuth beam pointing is corrected from (-10°, 10°) to (-60°, 60°), and the grating lobe level suppression is improved by 11dB when the elevation beam pointing is corrected from (-5°, 5°) to (-45°, 45°). It can be seen that the phased array system proposed by the present invention can greatly reduce the grating lobe level of the large-spacing sub-array phased array system and improve the beam pointing accuracy.

[0058] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope 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 pathway module, and beam control and forming module; The codeable metasurface module is arranged above the phased array antenna module, and the codeable metasurface is communicatively connected with the beam control and forming module; the phased array antenna module is communicatively connected with the beam control and forming module through the receiving and transmitting path module; Among them, the beam control and forming module is used to control the phased array antenna module to perform beam scanning; 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.

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

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 6, characterized in that: The compensation phase can be generated according to the following formula: β p ′ q =kmd x you+kid y v(m=1,2...16,n=1,2...16); In the formula, is the phase distribution of the encodable metasurface module, β p ' q is the excitation phase of the antenna unit of the single-channel phased array system, β p ″ q is for β p ' q 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 elevation 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 control 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 sub-oscillator.

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