2-bit multi-polarization reconfigurable electric control metasurface antenna

Abstract

The invention discloses a 2-bit multi-polarization reconfigurable electric control metasurface antenna which comprises a linear polarization feed source horn and a reflection type metasurface. The reflective metasurface comprises a plurality of metasurface units arranged periodically, and each metasurface unit comprises a first metal layer, a first dielectric plate, a second metal layer, a prepreg layer, a third metal layer, a second dielectric plate and a fourth metal layer which are sequentially and coaxially stacked from top to bottom. And two pairs of p-i-n diodes are integrated on each metasurface unit and are used for regulating and controlling linearly polarized waves from the feed source. According to the metasurface antenna, the radiation capacity of dual linear polarization and dual circular polarization is achieved through the single linear polarization feed source and the single reflection type metasurface at the same time, the beam scanning capacity of + / -60 degrees is achieved, and the aperture efficiency is high. In addition, a direct-current control circuit for controlling a p-i-n diode switch is designed on the back surface of the reflective metasurface, so that the integration level of the metasurface system is greatly improved. The metasurface antenna has the advantages of being simple in structure, large in polarization number, low in structural complexity and high in integration degree.

Description

Technical Field

[0001] The present invention belongs to the technical field of electromagnetic wave beamforming, and in particular relates to a 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna. Background Art

[0002] Traditional methods for rapid antenna beamforming and scanning use mechanically rotating parabolic antennas or phased array antennas. However, antennas used in long-distance wireless communications, such as satellite communications and deep space exploration, are often bulky, with limited mechanical rotation speed and beam pointing accuracy. While phased array antennas offer rapid beamforming and scanning capabilities, their feed networks are complex and subject to high losses. Furthermore, the transceiver components of phased array antennas are often costly. Electromagnetic metasurfaces enable flexible control of electromagnetic waves. By integrating electrically controlled RF devices such as pin diodes and varactor diodes, metasurfaces possess the ability to rapidly manipulate electromagnetic waves in real time. Compared to mechanically rotating parabolic antennas, metasurface antennas offer the advantages of fast beamforming and precise scanning. Compared to phased array antennas, air-fed metasurface antennas eliminate the complex feed networks and transceiver components, offering the advantages of low complexity and low cost. In recent years, metasurface antennas have become a research hotspot in the electromagnetic field.

[0003] Most current reconfigurable metasurface antennas only offer 1-bit phase correction, which divides the 360-degree phase of the electromagnetic wave into a single bit, representing two states: "0" and "1." This coarse phase control results in approximately 3dB of antenna directivity loss. To improve the antenna's aperture efficiency, a 2-bit phase correction scheme is employed, dividing the 360-degree phase of the electromagnetic wave into two bits, representing four states: "00," "01," "10," and "11." For example: Y. Yin et al. (Y. Yin et al., "Design of a 2-bit Dual-Polarized Reconfigurable Reflectarray With High Aperture Efficiency," IEEE Trans. Antennas Propag., vol. 72, no. 1, pp. 542-552, Jan. 2024.) proposed a 2-bit dual-polarized electrically controlled reconfigurable metasurface antenna. Its unit uses an aperture coupling patch and a microstrip phase delay line located behind its floor. Two pin diodes are loaded on each delay line. By controlling the opening or closing of the diode, the length of the delay line is changed, thereby realizing 2-bit phase control. By deploying two vertical coupling slots and two phase delay lines, the dual-linear polarization is independently controlled. L.Zhu et al. (L.Zhu et al., "Dual Linearly Polarized 2-bit Programmable Metasurface With High Cross-Polarization Discrimination," IEEE Trans.Antennas Propag., vol.72, no.2, pp.1510-1520, Feb.2024.) proposed a 2-bit dual-linearly polarized electrically controlled reconfigurable metasurface antenna. Its unit is a dipole structure that can support ±45° dual-linear polarization operation; and the unit integrates two pairs of pin diodes, each pair of diodes independently controls one linear polarization operation, and achieves 2-bit control of the reflection phase by optimizing the loading position of the diodes.N.Yang et al. (N.Yang et al., "A 2-Bit Programmable Reflectarray Antenna Based on a Polarization-Insensitive Metasurface," IEEE Trans.AntennasPropag., vol.72, no.7, pp.5539-5549, Jul.2024.) proposed a 2-bit dual-linear polarization electrically controlled reconfigurable metasurface antenna. Its unit is connected to two phase delay lines of different lengths through a pair of diodes. By turning the diodes on or off, ground paths of different lengths are switched, thereby achieving 2-bit phase control; by symmetrically placing another pair of diodes and phase delay lines of different lengths, 2-bit phase control of dual-linear polarization is achieved.

[0004] However, existing 2-bit electrically controlled reconfigurable metasurface antennas have the following disadvantages:

[0005] (1) Existing 2-bit electrically controlled reconfigurable metasurface antennas have a limited number of polarizations, typically operating in single- or dual-linear polarization modes. Increasing the number of polarizations can help improve channel capacity in communications and increase applicability in multiple scenarios. For example, dual-linear polarization can be used in base stations, and dual-circular polarization can be used in satellite communications.

[0006] (2) Existing 2-bit electrically controlled reconfigurable metasurface antennas that support dual-polarization operation often have very complex structures. Their units have a large number of dielectric layers, metallized holes, and RF components, which are complex to prepare and have high processing costs.

[0007] (3) The existing 2-bit electrically controlled reconfigurable metasurface antennas that support dual-polarization operation have a low level of integration. This is because the metasurface and the DC control board are often separated, and a large number of cables are required to connect the two modules in order to achieve the regulation of the switching states of all diodes on the metasurface. Therefore, the system complexity is high and the integration level is also low. Summary of the Invention

[0008] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna operating in the S band, which not only has a 2-bit reflection phase correction capability, but also further improves the number of polarizations, can support dual-linear polarization and dual-circular polarization radiation, and has more excellent radiation performance. The metasurface antenna of the present invention has a beam scanning capability of ±60°, and the maximum scanning loss in all polarizations can be limited to within 3.34dB. In the metasurface antenna of the present invention, each metasurface unit only uses two layers of dielectrics, five metallized through-holes and five RF components. The number of structures is significantly lower than that of the existing 2-bit dual-linear polarization electrically controlled reconfigurable metasurface antenna, which greatly reduces the processing complexity and processing cost. In addition, the present invention realizes the integrated packaging of the metasurface and its DC control circuit by arranging the DC control circuit behind the metasurface, which does not require a large number of wiring connections, greatly improving the integration of the system. The metasurface antenna of the present invention is capable of high-speed electronically controlled beam scanning, and has the characteristics of high aperture efficiency, a large number of polarizations, a wide beam scanning range, and low scanning loss, and has a simple structure and high integration.

[0009] In order to achieve the above-mentioned object of the invention, the technical solutions adopted by the present invention are as follows:

[0010] A 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna, comprising a linearly polarized feed horn 1 and a reflective metasurface 2;

[0011] The reflective metasurface 2 includes a plurality of periodically arranged metasurface units 21, each of which includes a metal layer 1 211, a dielectric plate 1 212, a metal layer 213, a prepreg layer 214, a metal layer 3 215, a dielectric plate 216, and a metal layer 4 217 stacked from top to bottom; each metasurface unit 21 is integrated with two pairs of PIN diodes for regulating the linearly polarized wave from the linearly polarized feed horn 1;

[0012] Vertically penetrating metallized through holes are provided around and at the center of the super-surface unit 21, and the metallized through holes provided around the super-surface unit 21 are connected to metal layer one 211, metal layer three 215 and metal layer four 217, and are not connected to metal layer two 213; the metallized through hole provided at the center of the super-surface unit 21 is connected to metal layer one 211, metal layer two 213 and metal layer four 217, and is not connected to metal layer three 215; the metal layer three 215 is connected to metal layer four 217 through three vertically penetrating metallized blind holes, and the metallized blind holes are arranged along the +x-axis direction with an interval of one super-surface unit 21.

[0013] The metal layer 1 211 includes a square patch 2116 located on the dielectric plate 1 212, with a cross-shaped groove processed in the center of the square patch 2116, and a cross-shaped patch 2117 is arranged in the cross-shaped groove; rectangular patches are arranged around the square patch 2116, and the four rectangular patches are the same size, and rectangular patches of different sizes are arranged opposite to each other; pin diodes are welded between the square patch 2116 and the four rectangular patches, namely pin diode 1 2122, pin diode 2 2123, pin diode 3 2124 and pin diode 4 2125; the ends of the four rectangular patches away from the center of the square patch 2116 and the center of the cross-shaped patch 2117 are vertically penetrated by metallized through-holes.

[0014] The pin diode 1 2122 and the pin diode 2 2123 are arranged opposite to each other, and the angle between their welding directions and the +x axis is +45°; the diode 3 2124 and the pin diode 4 2125 are arranged opposite to each other, and the angle between their welding directions and the +x axis is -45°.

[0015] The second metal layer 213 is a floor for controlling the DC signal of the PIN diode and is also a reflector for the RF signal. The second metal layer 213 is etched with an isolation ring surrounding the metallized through holes on all sides, and the outer diameter of the isolation ring is larger than the diameter of the metallized through hole. The second metal layer 213 does not contact the metallized through holes on all sides, but contacts the metallized through hole in the center.

[0016] The metal layer three 215 includes four metal disks arranged around the top surface of the dielectric plate two 216 and three bias metal wires arranged in the middle of the top surface of the dielectric plate two 216; the four metal disks are in contact with the metallized through holes on all sides, and the three bias metal wires are in contact with the three metallized blind holes, and the bias metal wires are arranged along the +x-axis direction with one super surface unit 21 spaced apart.

[0017] The metal layer four 217 is a DC control circuit arranged on the back side of the dielectric plate two 216, including periodically arranged shift register chips 2134, and the shift register chips 2134 are cascaded in pairs. The eight output ports of each shift register chip 2134 are respectively connected to the metallized through holes of the two super-surface units 21, and these metallized through holes are metallized through holes arranged around the super-surface units 21; each output port of the shift register chip 2134 is connected in series with a resistor 2135; the other three pins of the shift register chip 2134 are respectively connected to the three bias metal wires of the metal layer three 215 through three metallized blind holes.

[0018] The linear polarization feed horn 1 includes a coaxial waveguide converter 11 , which is connected to a horn mouth 12 via a flange.

[0019] The metasurface antenna supports dual-polarization working modes as follows:

[0020] (1) When the feed polarization direction is +45°, the polarization direction of the metasurface antenna is also +45°, and the beam scanning depends on the switching state of the PIN diode 1 2122 and the PIN diode 2 2123 in each metasurface unit 21;

[0021] (2) When the feed polarization direction is -45° polarization, the polarization direction of the metasurface antenna is also -45° polarization, and the beam scanning depends on the switching state of the pin diode three 2124 and the pin diode four 2125 in each metasurface unit 21.

[0022] The metasurface antenna supports dual circular polarization in the following working modes:

[0023] (1) When the polarization direction of the feed source is y-polarization, if the +45° polarization reflection phase introduced by the switching state of the PIN diode 1 2122 and the PIN diode 2 2123 leads the -45° polarization reflection phase introduced by the switching state of the PIN diode 3 2124 and the PIN diode 4 2125 by 90°, the polarization mode of the metasurface antenna is right-hand circular polarization; if the +45° polarization reflection phase introduced by the switching state of the PIN diode 1 2122 and the PIN diode 2 2123 lags the -45° polarization reflection phase introduced by the switching state of the PIN diode 3 2124 and the PIN diode 4 2125 by 90°, the polarization mode of the metasurface antenna is left-hand circular polarization;

[0024] (2) When the polarization direction of the feed source is x-polarization, if the +45° polarization reflection phase introduced by the switching state of PIN diode 1 2122 and PIN diode 2 2123 leads the -45° polarization reflection phase introduced by the switching state of PIN diode 3 2124 and PIN diode 4 2125 by 90°, the polarization mode of the metasurface antenna is left-hand circular polarization; if the +45° polarization reflection phase introduced by the switching state of PIN diode 1 2122 and PIN diode 2 2123 lags the -45° polarization reflection phase introduced by the switching state of PIN diode 3 2124 and PIN diode 4 2125 by 90°, the polarization mode of the metasurface antenna is right-hand circular polarization.

[0025] The reflection phase that needs to be compensated for each metasurface unit 21 satisfies the following formula:

[0026]

[0027] in, represents the reflection phase required by the (m,n)th metasurface unit 21, k represents the free space wave number, r fmn represents the distance between the (m,n)th metasurface unit 21 and the feed phase center, r f represents the distance between the phase center of the feed source and the center of the reflective metasurface 2, represents the unit vector of the metasurface antenna beam pointing direction, represents the position vector of the (m,n)th metasurface unit 21, Indicates the introduced reference phase;

[0028] The switching states of the four pin diodes are calculated according to the compensated reflection phase formula (1) and the following formula (2):

[0029]

[0030] in, represents the phase required to be compensated for each metasurface unit 21 in the reflective metasurface 2 calculated by formula (1).

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] 1. The metasurface unit structure of the present invention first realizes the independent control of dual-linear polarization electromagnetic waves, and then realizes the radiation capability of dual circular polarization by introducing a phase difference of 90° or 270° in the orthogonal polarization direction. The metasurface antenna of the present invention only requires a single linear polarization feed source and can simultaneously realize the radiation capability of dual linear polarization and dual circular polarization. The number of polarizations is rich, which improves the channel capacity of the antenna and the applicability of multiple scenarios. Therefore, the metasurface antenna of the present invention can be applied to application scenarios such as base stations (dual linear polarization) and satellite communications (dual circular polarization).

[0033] 2. The metasurface antenna of the present invention has a simple structure. Each metasurface unit uses only two layers of dielectric plates, five metallized through holes and five RF components, which significantly reduces processing complexity and cost.

[0034] 3. Based on the proposed interlayer equivalent capacitance concept, this invention achieves isolation between RF and DC through the distributed capacitance formed between metal layers 2 and 3, preventing crosstalk and providing ample space for the on-demand design of the underlying DC control circuit. This invention periodically arranges shift register chips behind the metasurface, directly controlling the opening and closing of PIN diodes through metallized vias, eliminating the need for complex and numerous wiring connecting the DC circuit control board and the metasurface. This enables single-board integration of the metasurface and its DC control circuit, further reducing the system profile, cost, and complexity, and significantly improving system integration.

[0035] 4. Compared with the beam scanning method of mechanically rotating antennas, the metasurface antenna structure of the present invention has the ability of electrically controlled beam scanning. In the dual linear polarization and dual circular polarization working modes, the aperture efficiency is greater than 30%, and beam scanning with any pointing angle of 0° to 60° and 0° to 360° in azimuth can be achieved, with a wide beam scanning range; at the same time, it has the advantages of fast scanning speed and precise pointing.

[0036] 5. Compared with phased array antennas, the metasurface antenna of the present invention is based on electromagnetic metasurface design and adopts space feeding. It does not require complex feeding networks and high-cost transceiver components. It has the advantages of simple feeding, low cost, and easy processing and integration.

[0037] In summary, the metasurface antenna of the present invention is capable of high-speed electronically controlled beam scanning, and has the characteristics of high aperture efficiency, a large number of polarizations, a wide beam scanning range, and low scanning loss, and has a simple structure and high integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the structure of the metasurface antenna of the present invention.

[0039] Figure 2 Schematic diagram of the structure of the metasurface unit of the metasurface antenna of the present invention, wherein (a) is a side view of a 2×2 metasurface unit; (b) is a hierarchical relationship diagram of the metasurface unit; (c) is a top view of the metal layer one of a single metasurface unit; (d) is a top view of the metal layer two of a single metasurface unit; (e) is a top view of the metal layer three of a single metasurface unit; and (f) is a bottom view of the metal layer four of the 2×2 metasurface unit.

[0040] Figure 3 This is a physical picture of the reflective metasurface of the metasurface antenna of the present invention.

[0041] Figure 4 These are the simulation results of the dual-linear polarization reflection coefficient of the metasurface unit of the present invention, where (a) is the +45° polarized electromagnetic wave incident, and (b) is the -45° polarized electromagnetic wave incident.

[0042] Figure 5 These are the simulation results of the gain and radiation pattern of the metasurface antenna of the present invention when operating at +45° polarization, where (a) is the gain versus frequency curve, (b) is the beam scanning radiation pattern, and (c) is the cross-polarization level of the metasurface antenna within the beam scanning range.

[0043] Figure 6 These are the simulation results of the gain and radiation pattern of the metasurface antenna of the present invention when operating at -45° polarization, where (a) is the gain versus frequency curve, (b) is the beam scanning radiation pattern, and (c) is the cross-polarization level of the metasurface antenna within the beam scanning range.

[0044] Figure 7 These are the simulation results of the gain and radiation pattern of the metasurface antenna of the present invention when operating in left-hand circular polarization, where (a) is the gain versus frequency curve, (b) is the axial ratio versus frequency curve, (c) is the beam scanning radiation pattern, and (d) is the axial ratio of the metasurface antenna within the beam scanning range.

[0045] Figure 8 The simulation results of the gain and radiation pattern of the metasurface antenna of the present invention when operating in right-hand circular polarization, where (a) is the gain-versus-frequency curve, (b) is the axial ratio-versus-frequency curve, (c) is the beam scanning radiation pattern, and (d) is the axial ratio of the metasurface antenna within the beam scanning range.

[0046] Figure 9 Schematic diagram of the structure of the metasurface antenna of Example 1, where (a) is +45° polarization and (b) is -45° polarization.

[0047] Figure 10 These are the gain and radiation pattern test results of the metasurface antenna of Example 1 when operating at +45° polarization, where (a) is the gain versus frequency curve, (b) is the beam scanning radiation pattern, and (c) is the cross-polarization level of the metasurface antenna within the beam scanning range.

[0048] Figure 11 These are the gain and radiation pattern test results of the metasurface antenna of Example 1 when operating at -45° polarization, where (a) is the gain versus frequency curve, (b) is the beam scanning radiation pattern, and (c) is the cross-polarization level of the metasurface antenna within the beam scanning range.

[0049] Figure 12 This is a structural diagram of the metasurface antenna of Example 2.

[0050] Figure 13These are the gain and radiation pattern test results of the metasurface antenna of Example 2 when operating in left-hand circular polarization, (a) is the gain variation curve with frequency, (b) is the axial ratio variation curve with frequency, (c) is the beam scanning radiation pattern, and (d) is the axial ratio of the metasurface antenna within the beam scanning range.

[0051] Figure 14 These are the gain and radiation pattern test results of the metasurface antenna of Example 2 when operating in right-hand circular polarization, (a) is the gain variation curve with frequency, (b) is the axial ratio variation curve with frequency, (c) is the beam scanning radiation pattern, and (d) is the axial ratio of the metasurface antenna within the beam scanning range.

[0052] In the figure: linear polarization feed horn 1, coaxial waveguide converter 11, horn mouth 12, reflective metasurface 2, metasurface unit 21, metal layer 1 211, dielectric plate 1 212, metal layer 2 213, prepreg layer 214, metal layer 3 215, dielectric plate 2 216, metal layer 4 217, metalized through hole 1 218, metalized through hole 2 219, metalized through hole 3 2110, metalized through hole 4 2111, metalized through hole 5 2112, metalized blind hole 1 2113, metalized blind hole 2 2114, metalized blind hole 3 2115, square patch 2116, ten Glyph patch 2117, rectangular patch one 2118, rectangular patch two 2119, rectangular patch three 2120, rectangular patch four 2121, pin diode one 2122, pin diode two 2123, pin diode three 2124, pin diode four 2125, inductor 2126, metal disc one 2127, metal disc two 2128, metal disc three 2129, metal disc four 2130, bias metal line one 2131, bias metal line two 2132, bias metal line three 2133, shift register chip 2134, resistor 2135. DETAILED DESCRIPTION

[0053] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different perspectives and applications without departing from the spirit of the present invention.

[0054] like Figure 1 As shown, a 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna includes a linearly polarized feed horn 1 and a reflective metasurface 2; the linearly polarized feed horn 1 is the feed source of the metasurface antenna. After it emits a quasi-spherical electromagnetic wave that reaches the reflective metasurface 2, the reflective metasurface 2 performs a 2-bit reflection phase correction on the quasi-spherical electromagnetic wave to form a high-gain quasi-plane wave for radiation.

[0055] The linearly polarized feed horn 1 includes a coaxial waveguide converter 11 connected to a horn mouth 12 via a flange. The coaxial waveguide converter 11 is a standard waveguide WR-229 model with an operating frequency range of 3.22-4.9 GHz. The horn mouth 12 is CNC machined to achieve more uniform E- and H-plane wavewidths, thereby improving the aperture efficiency of the metasurface antenna. The phase center of the linearly polarized feed horn 1 is located directly above the reflective metasurface 2, 375 mm from the center of the reflective metasurface 2, achieving a balance between illumination efficiency and overflow efficiency.

[0056] like Figure 2 (a) and Figure 2 As shown in (b) of FIG. 1 , the reflective metasurface 2 includes a plurality of periodically arranged metasurface units 21, each of which includes a metal layer 1 211, a dielectric plate 1 212, a metal layer 2 213, a prepreg layer 214, a metal layer 3 215, a dielectric plate 2 216, and a metal layer 4 217 coaxially stacked from top to bottom. The dielectric plate 1 212, the metal layer 2 213, the prepreg layer 214, and the dielectric plate 2 216 have the same periodic size and different thicknesses.

[0057] like Figure 2 (d) and Figure 2 As shown in (e), the metasurface unit 21 further includes five vertically penetrating metallized through holes for establishing electrical connections between metal layers to achieve signal transmission; the metallized through holes are respectively metallized through hole 1 218, metallized through hole 219, metallized through hole 3 2110, metallized through hole 4 2111 arranged around the metasurface unit 21, and metallized through hole 5 2112 arranged at the center of the metasurface unit 21; the metallized through hole 1 218, metallized through hole 219, metallized through hole 3 2110, metallized through hole 4 2111 are all connected to the metal layer 1 21 1. Metal layer three 215 is connected to metal layer four 217, but is not connected to metal layer two 213; the metalized through-hole five 2112 is connected to metal layer one 211, metal layer two 213 and metal layer four 217, but is not connected to metal layer three 215; the metal layer three 215 is connected to metal layer four 217 through three vertically penetrating metalized blind holes, and the metalized blind holes are arranged along the +x-axis direction with one super-surface unit 21 spaced apart, that is, the metalized blind holes are only set on odd-numbered super-surface units 21 or even-numbered super-surface units 21, and adjacent super-surface units 21 are not set with metalized blind holes.

[0058] like Figure 2As shown in (c), the metal layer 1 211 includes a square patch 2116 located on the dielectric plate 1 212, the center of the square patch 2116 is processed with a cross-shaped groove, and a cross-shaped patch 2117 is arranged in the cross-shaped groove; the square patch 2116 is surrounded by rectangular patches, namely rectangular patch 1 2118, rectangular patch 2 2119, rectangular patch 3 2120, and rectangular patch 4 2121; the rectangular patch 1 2118 and the rectangular patch 3 2120 are of the same size, and the rectangular patch 2 2119 and the rectangular patch 4 2121 are of the same size , and rectangular patches of different sizes are arranged relative to each other; PIN diodes are welded between the square patch 2116 and the rectangular patches, namely PIN diode 1 2122, PIN diode 2 2123, PIN diode 3 2124, and PIN diode 4 2125; PIN diode 1 2122 and PIN diode 2 2123 are arranged relative to each other, with the angle between their welding directions and the +x axis being +45°; diode 3 2124 and PIN diode 4 2125 are arranged relative to each other, with the angle between their welding directions and the +x axis being -45°. An inductor 2126 is welded between the square patch 2116 and one end of the cross-shaped patch 2117, which is used to pass a DC signal, that is, to control the opening and closing of the PIN diode, while simultaneously suppressing the passage of RF signals. The ends of the four rectangular patches away from the center of metal layer 1 211 and the center of the cross-shaped patch 2117 all contact the metallized through-holes.

[0059] like Figure 2 As shown in (d), metal layer 213 serves as a ground plane for controlling the DC signal of the PIN diode and also as a reflector for RF signals. Metal layer 213 is etched with an isolation ring surrounding PTH 1 218, PTH 2 219, PTH 3 2110, and PTH 4 2111. The outer diameter of the isolation ring is larger than the diameter of the PTH. Therefore, metal layer 213 does not contact PTH 1 218, PTH 2 219, PTH 3 2110, and PTH 4 2111, but contacts PTH 5 2112.

[0060] like Figure 2As shown in (e), the metal layer three 215 includes four metal disks arranged around the top surface of the dielectric plate two 216 and three bias metal wires arranged in the middle of the top surface of the dielectric plate two 216; the four metal disks are respectively metal disk one 2127, metal disk two 2128, metal disk three 2129, and metal disk four 2130; the three bias metal wires are respectively bias metal wire one 2131, bias metal wire two 2132, and bias metal wire three 2133; the metal disk one 2127, metal disk two 2128, metal disk three 2129, and metal disk four 2130 are respectively bias metal wire one 2131, bias metal wire two 2132, and bias metal wire three 2133. The bias metal wires 1 2131, 2132 and 2133 are respectively connected to the metallized through hole 1 2113, 2114 and 2115, and the bias metal wires are arranged along the +x-axis direction with one metasurface unit 21 spaced apart, that is, the bias metal wires are only provided on the odd-numbered metasurface units 21 or the even-numbered metasurface units 21, while the bias metal wires are not provided on the adjacent metasurface units 21.

[0061] like Figure 2 As shown in (f), the metal layer four 217 is a DC control circuit arranged on the back of the dielectric plate two 216, including periodically arranged shift register chips 2134. The shift register chips 2134 convert the serial digital signals from the single-chip microcomputer into parallel digital signals to achieve synchronous control of the switching states of all PIN diodes; the shift register chips 2134 are cascaded in pairs, and the eight output ports of each shift register chip 2134 are respectively connected to the metallized through hole 1 218, metallized through hole 219, metallized through hole 3 2110 and metallized through hole 4 2111 of the two metasurface units 21, for controlling the conduction and shutdown of the eight PIN diodes on the two metasurface units 21. Each output port of the shift register chip 2134 is connected in series with a resistor 2135 with a resistance of 240Ω to limit the output current and prevent current overload from burning out the pin diode; to prevent the control lines from crossing, some control lines are placed on the metal layer three 215, and the other three pins of the shift register chip 2134 are connected to the bias metal line 1 2131, the bias metal line 2 2132 and the bias metal line 3 2133 through the metallized blind via 1 2113, the metallized blind via 2 2114 and the metallized blind via 3 2115 respectively.

[0062] The reflective metasurface 2 is processed by standard PCB technology, and components such as pin diodes, inductors, shift register chips, and resistors are all soldered by SMT technology. Traditional electrically controlled reconfigurable metasurfaces use a design that separates the metasurface and the DC control circuit board, requiring hundreds or even thousands of cables to connect the two modules. The present invention, based on the RF and DC isolation structure of distributed capacitors, can cleverly place the shift register chip 2134 periodically behind the metasurface, eliminating the need for a large number of cables to connect the two modules. Therefore, the complexity of the reflective metasurface 2 is significantly reduced, the cross-section of the actual processed system is reduced, and the integration level is significantly improved. Figure 3 shown.

[0063] For beam scanning applications, in order to achieve beam pointing at a specific angle, based on the array antenna principle, the reflection phase that needs to be compensated by each metasurface unit 21 of the metasurface antenna satisfies the following formula:

[0064]

[0065] in, represents the reflection phase required by the (m,n)th metasurface unit 21, k represents the free space wave number, r fmn represents the distance between the (m,n)th metasurface unit 21 and the feed phase center, r f represents the distance between the phase center of the feed source and the center of the reflective metasurface 2, represents the unit vector of the metasurface antenna beam pointing direction, represents the position vector of the (m,n)th metasurface unit 21, Represents the reference phase introduced to optimize the metasurface antenna pattern.

[0066] The switching states of the four pin diodes are calculated based on the compensated reflection phase formula (1) and the following formula (2):

[0067]

[0068] in, represents the phase required to be compensated for each metasurface unit 21 in the reflective metasurface 2 calculated by formula (1).

[0069] The metasurface antenna supports dual-polarization working modes as follows:

[0070] (1) When the feed polarization direction is +45°, the polarization direction of the metasurface antenna is also +45°, and the beam scanning depends on the switching state of the PIN diode 1 2122 and the PIN diode 2 2123 in each metasurface unit 21;

[0071] (2) When the feed polarization direction is -45° polarization, the polarization direction of the metasurface antenna is also -45° polarization, and the beam scanning depends on the switching state of the pin diode three 2124 and the pin diode four 2125 in each metasurface unit 21.

[0072] The metasurface antenna supports dual circular polarization in the following working modes:

[0073] (1) When the polarization direction of the feed source is y-polarization, if the +45° polarization reflection phase introduced by the switching state of the PIN diode 1 2122 and the PIN diode 2 2123 leads the -45° polarization reflection phase introduced by the switching state of the PIN diode 3 2124 and the PIN diode 4 2125 by 90°, the polarization mode of the metasurface antenna is right-hand circular polarization; if the +45° polarization reflection phase introduced by the switching state of the PIN diode 1 2122 and the PIN diode 2 2123 lags the -45° polarization reflection phase introduced by the switching state of the PIN diode 3 2124 and the PIN diode 4 2125 by 90°, the polarization mode of the metasurface antenna is left-hand circular polarization;

[0074] (2) When the polarization direction of the feed source is x-polarization, if the +45° polarization reflection phase introduced by the switching state of PIN diode 1 2122 and PIN diode 2 2123 leads the -45° polarization reflection phase introduced by the switching state of PIN diode 3 2124 and PIN diode 4 2125 by 90°, the polarization mode of the metasurface antenna is left-hand circular polarization; if the +45° polarization reflection phase introduced by the switching state of PIN diode 1 2122 and PIN diode 2 2123 lags the -45° polarization reflection phase introduced by the switching state of PIN diode 3 2124 and PIN diode 4 2125 by 90°, the polarization mode of the metasurface antenna is right-hand circular polarization.

[0075] The working principle of the metasurface antenna of the present invention is as follows:

[0076] Principle of RF and DC signal isolation: Metal layer 213 forms a distributed capacitor with metal layer 3 215. When RF current reaches metal layer 3 215 through the metalized vias, it connects to metal layer 213 via the distributed capacitor and does not enter metal layer 4 217. This prevents RF signals from entering the DC control circuit, isolating the RF and DC signals and preventing crosstalk. Furthermore, the DC control circuitry in metal layer 4 217 can be designed as needed without affecting the RF performance of the metasurface antenna.

[0077] Dual-polarization operating principle: PIN diodes 1 2122 and 2123 provide 2-bit reflected phase correction for incident waves with a +45° polarization, while PIN diodes 3 2124 and 4 2125 provide 2-bit reflected phase correction for incident waves with a -45° polarization. The cross-slot structure of the metasurface unit 21 effectively guides the RF current along the main polarization direction, significantly suppressing cross-polarization. Therefore, the ±45° dual-polarized electromagnetic waves can be independently controlled by the diodes in the corresponding directions, unaffected by the switching state of the other pair of diodes.

[0078] Working principle of dual circular polarization: When the feed source transmits an x / y polarized electromagnetic wave, the x / y polarized incident wave can be decomposed into a pair of ±45° polarized electromagnetic waves with equal amplitude and phase, which are independently controlled by PIN diode 1 2122 and PIN diode 2 2123, as well as PIN diode 3 2124 and PIN diode 4 2125. The switching state of PIN diode 1 2122 and PIN diode 2 2123 affects the reflected phase of the +45° polarized incident wave as follows: The reflection phase of the switching state of the pin diode 3 2124 and the pin diode 4 2125 for the -45° polarized incident wave is recorded as When the feed source emits y-polarized electromagnetic waves, and When , the metasurface antenna operates in right-hand circular polarization; when and When , the metasurface antenna works in left-hand circular polarization. Similarly, when the feed emits x-polarized electromagnetic waves, and When , the metasurface antenna operates in left-hand circular polarization; when and When , the metasurface antenna operates in right-hand circular polarization.

[0079] The proposed 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna was simulated and verified based on the full-wave electromagnetic simulation software HFSS.

[0080] When a +45° polarized electromagnetic wave is incident, the reflection coefficient of the metasurface unit 21 is as follows: Figure 4 As shown in (a), as the states of pin diode 1 2122 and pin diode 2 2123 switch, the unit forms a 2-bit reflection phase state near 3.5 GHz. In addition, the state changes of pin diode 3 2124 and pin diode 4 2125 have little effect on the reflection phase. When a -45° polarized electromagnetic wave is incident, the reflection coefficient of the metasurface unit 21 is as follows: Figure 4As shown in (b), as the states of pin diode three 2124 and pin diode four 2125 are switched, the metasurface unit 21 forms a 2-bit reflection phase state at around 3.5 GHz. In addition, the state changes of pin diode one 2122 and pin diode two 2123 have little effect on the reflection phase. The above simulation results show that the proposed metasurface unit 21 has the ability to independently control dual linear polarization. The legend above all reflection coefficient simulation graphs appearing in the present invention indicates the switching state of the pin diode, such as "10 / 01", the first pair of numbers represents that the switching state of pin diode one 2122 and pin diode two 2123 is "10", and the second pair of numbers represents that the switching state of pin diode three 2124 and pin diode four 2125 is "01".

[0081] The simulation results of ±45° dual-polarization of the metasurface antenna are as follows: Figure 5 and Figure 6 As shown. Figure 5 (a) and Figure 6 As shown in (a) of the figure, the maximum gain of the metasurface antenna when operating at ±45° polarization is 20.67dBi and 20.59dBi, respectively, corresponding to aperture efficiencies of 38.67% and 37.43%, and 3dB gain bandwidths of 9.26% and 8.70%, respectively. The beam scanning pattern at the 3.5GHz center frequency is shown in the figure. Figure 5 (b) and Figure 6 As shown in (b), a good pencil beam can be observed, and the metasurface antenna has the ability to scan the beam of ±60° with dual linear polarization, and the scanning losses are 3.66dB and 3.44dB respectively. Figure 5 (c) and Figure 6 As shown in (c), the cross-polarization levels of the metasurface antenna within the beam scanning range are lower than -30.30dB and -31.28dB respectively.

[0082] The simulation results of dual circular polarization of metasurface antenna are as follows: Figure 7 and Figure 8 As shown. Figure 7 (a) and Figure 8 As shown in (a) of the figure, the maximum gain of the metasurface antenna in left-handed / right-handed circular polarization is 20.12dBic and 20.01dBic respectively, with corresponding aperture efficiencies of 34.07% and 33.22% and 3dB gain bandwidths of 12.52% and 12.79% respectively. Figure 7 (b) and Figure 8 As shown in (b) of Figure 1, the 3dB axial ratio bandwidths of the metasurface antenna are 6.01% and 5.17% respectively. The dual circularly polarized beam scanning pattern at the 3.5GHz center frequency is shown in Figure 1. Figure 7 (c) and Figure 8 As shown in (c), a good pencil beam can be observed, and the metasurface antenna has the ability to scan the beam of ±60° with dual circular polarization, and the scanning losses are 2.90dB and 3.38dB respectively. Figure 7 (d) and Figure 8 As shown in (d) in the figure, the axial ratios of the metasurface antenna are lower than 1.85dB and 1.39dB respectively within the beam scanning range.

[0083] Example 1

[0084] Figure 9 This is a schematic diagram of the structure of the metasurface antenna when working in dual-polarization mode, where: Figure 9 (a) shows the metasurface antenna structure when operating at +45° polarization, and the polarization mode of the linearly polarized feed horn 1 is +45° polarization; Figure 9 (b) in the figure is the metasurface antenna structure when working with -45° polarization, and the polarization mode of the linearly polarized feed horn 1 is -45° polarization.

[0085] In this embodiment, the reflective metasurface 2 includes 12×12 periodically arranged metasurface units 21. The material of all metal layers, metal disks, and metal wires is copper with gold deposited on the surface; the model of all dielectric plates is F4BM220 with a dielectric constant of 2.2; the model of the semi-cured sheet layer is WL-PP300. The linearly polarized feed horn 1 and the metasurface antenna have the same polarization mode. When the linearly polarized feed horn 1 radiates a +45° polarized incident wave, the four switching state combinations of the pin diode 2122 and the pin diode 2123 in the metasurface unit 21 can produce 2-bit reflection phase control for the +45° polarized incident wave. According to different beam pointing angles, the working state of the pin diode 1 2122 and the pin diode 2 2123 in each metasurface unit 21 can be determined by formulas (1) and (2). The metasurface unit 21 has the ability to independently control dual linearly polarized electromagnetic waves, so the switching state of the pin diode 3 2124 and the pin diode 4 2125 are arbitrary. When the linearly polarized feed horn 1 radiates a -45° polarized incident wave, the four switching state combinations of PIN diode 3 2124 and PIN diode 4 2125 in the metasurface unit 21 can produce 2-bit reflected phase control for the -45° polarized incident wave. Depending on the beam pointing angle, the operating states of PIN diode 3 2124 and PIN diode 4 2125 in each metasurface unit 21 can be determined by equations (1) and (2). The metasurface unit 21 has the ability to independently control dual linearly polarized electromagnetic waves, so the switching states of PIN diode 1 2122 and PIN diode 2 2123 are arbitrary.

[0086] The test results of the metasurface antenna in dual-polarization operation are as follows: Figure 10 and Figure 11 shown. Figure 10 (a) and Figure 11 (a) shows the frequency domain gain and aperture efficiency of the ±45° polarized side-firing beam of the metasurface antenna, with a sampling point set every 25MHz. The maximum gain of the ±45° polarized side-firing beam of the metasurface antenna is 20.19dBi and 20.28dBi, respectively, with corresponding aperture efficiencies of 34.63% and 35.35%, and 3dB operating bandwidths of 9.52% and 10.08%, respectively. The beam scanning pattern at the 3.5GHz center frequency is shown in Figure 2. Figure 10 (b) and Figure 11 As shown in (b), a good pencil beam can be observed, and the antenna has the ability to scan the beam of ±60° with dual linear polarization, and the scanning losses are 3.24dB and 3.15dB respectively. Figure 10 (c) and Figure 11 As shown in (c) of Figure 3, the cross-polarization levels of the antenna are lower than -23.67dB and -25.90dB within the scanning range. The test results of the metasurface antenna in dual-polarization operation are consistent with the corresponding simulation results.

[0087] Example 2

[0088] The structure of the metasurface antenna when working in dual circular polarization is as follows: Figure 12 As shown, the polarization mode of the linear polarization feed horn 1 is y-polarization.

[0089] In this embodiment, the reflective metasurface 2 includes 12×12 periodically arranged metasurface units 21. The material of all metal layers, metal disks, and metal wires is copper with gold deposited on the surface; the model of all dielectric plates is F4BM220 with a dielectric constant of 2.2; the model of the semi-cured sheet layer is WL-PP300. The polarization direction of the linearly polarized feed horn 1 is along the y-axis. The y-polarized incident wave can be decomposed into a pair of ±45° polarized electromagnetic waves, which are independently controlled by pin diode one 2122, pin diode two 2123, pin diode three 2124, and pin diode four 2125. Since the proposed metasurface unit 21 has an independent 2-bit reflection phase correction capability for ±45° dual linear polarization electromagnetic waves, the metasurface unit 21 can introduce a reflection phase difference of +90° or -90° between the pair of orthogonal directions of ±45°, thereby realizing the polarization conversion from linear polarization to dual circular polarization. According to different beam pointing angles, the reference phase in the ±45° direction It is necessary to ensure a difference of +90° or -90°. The working states of the pin diode 1 2122, the pin diode 2 2123, the pin diode 3 2124, and the pin diode 4 2125 in each metasurface unit 21 can be determined by formula (1) and formula (2) respectively.

[0090] The test results of the metasurface antenna in dual circular polarization are as follows: Figure 13 and Figure 14 shown. Figure 13 (a) and Figure 14 Figure (a) shows the frequency domain gain and aperture efficiency of the metasurface antenna's dual circularly polarized side-firing beams, with sampling points set every 25 MHz. The maximum gains of the metasurface antenna's ±45° polarized side-firing beams are 19.85 dBic and 19.67 dBic, respectively, corresponding to aperture efficiencies of 32.02% and 30.72%, and 3dB gain bandwidths of 11.66% and 12.52%, respectively. Figure 13 (b) and Figure 14 (b) is the frequency domain axial ratio of the dual circularly polarized side-beam of the metasurface antenna. The 3dB axial ratio bandwidths of the metasurface antenna are 5.71% and 5.73% respectively. The beam scanning pattern at the 3.5GHz center frequency is shown in Figure 2. Figure 13 (c) and Figure 14 As shown in (c), a good pencil beam can be observed, and the antenna has the ability to scan the beam of ±60° in dual circular polarization, with scanning losses of 3.34dB and 3.10dB respectively. Figure 13 (d) and Figure 14 As shown in (d) of Figure 3, the axial ratios of the metasurface antenna are lower than 2.32dB and 2.64dB respectively within the scanning range. The test results of the metasurface antenna in dual circular polarization are consistent with the corresponding simulation results.

[0091] In summary, the present invention discloses a 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna, which uses only a single linear polarization feed and a single metasurface, and can simultaneously support high-speed beam forming and scanning of dual linear polarization and dual circular polarization, providing hardware support for low-cost multi-channel wireless communication applications. The metasurface antenna of the present invention can achieve beam scanning in the range of 0° to 60° in elevation angle and 0° to 360° in azimuth angle when working in the above polarization, and the beam scanning range is wide. In addition, the metasurface antenna of the present invention also has the outstanding advantages of simple structure and high integration, and has broad application prospects in the fields of satellite communication, radar detection, wireless energy transmission and intelligent metasurface assisted communication.

[0092] The above description and embodiments are only preferred examples of the present invention and do not constitute any limitation to the present invention. Obviously, for professionals in this field, after understanding the content and design principles of the present invention, they may make various modifications and changes in form and details based on the principles and structure of the present invention. However, these modifications and changes based on the ideas of the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. A 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna, characterized by: It includes a linear polarization feed horn (1) and a reflective metasurface (2); The reflective metasurface (2) comprises a plurality of periodically arranged metasurface units (21), wherein the metasurface units (21) comprise a metal layer 1 (211), a dielectric plate 1 (212), a metal layer 2 (213), a prepreg layer (214), a metal layer 3 (215), a dielectric plate 2 (216), and a metal layer 4 (217) stacked from top to bottom; each metasurface unit (21) is integrated with two pairs of PIN diodes for regulating linearly polarized waves from a linearly polarized feed horn (1); The super surface unit (21) is provided with vertically penetrating metallized through holes around and at the center thereof, and the metallized through holes arranged around the super surface unit (21) are connected to the metal layer 1 (211), the metal layer 3 (215) and the metal layer 4 (217), but are not connected to the metal layer 2 (213); the metallized through hole arranged at the center of the super surface unit (21) is connected to the metal layer 1 (211), the metal layer 2 (213) and the metal layer 4 (217), but is not connected to the metal layer 3 (215); the metal layer 3 (215) is connected to the metal layer 4 (217) through three vertically penetrating metallized blind holes, and the metallized blind holes are arranged along the +x axis direction in a manner of being spaced apart by one super surface unit (21).

2. The 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna according to claim 1, characterized in that: The metal layer 1 (211) includes a square patch (2116) located on the dielectric plate 1 (212), the center of the square patch (2116) is processed with a cross-shaped groove, and a cross-shaped patch (2117) is arranged in the cross-shaped groove; rectangular patches are arranged around the square patch (2116), the four rectangular patches are of the same size, and the rectangular patches of different sizes are arranged opposite to each other; PIN diodes are welded between the square patch (2116) and the four rectangular patches, namely PIN diode 1 (2122), PIN diode 2 (2123), PIN diode 3 (2124) and PIN diode 4 (2125); the ends of the four rectangular patches away from the center of the square patch (2116) and the center of the cross-shaped patch (2117) are vertically penetrated by metallized through holes.

3. The 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna according to claim 2, characterized in that: The pin diode 1 (2122) and the pin diode 2 (2123) are arranged relative to each other, and the angle between their welding directions and the +x axis is +45°; the diode 3 (2124) and the pin diode 4 (2125) are arranged relative to each other, and the angle between their welding directions and the +x axis is -45°.

4. The 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna according to claim 1, characterized in that: The second metal layer (213) is a floor for controlling the DC signal of the PIN diode and is also a reflector for the radio frequency signal; the second metal layer (213) is etched with an isolation ring surrounding the metallized through holes on all sides, and the outer diameter of the isolation ring is larger than the diameter of the metallized through hole; the second metal layer (213) does not contact the metallized through holes on all sides, but contacts the metallized through hole in the center.

5. The 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna according to claim 1, characterized in that: The metal layer three (215) includes four metal disks arranged around the top surface of the dielectric plate two (216) and three bias metal wires arranged in the middle of the top surface of the dielectric plate two (216); the four metal disks are in contact with the metallized through holes on the four sides, and the three bias metal wires are in contact with the three metallized blind holes, and the bias metal wires are arranged along the +x-axis direction in a manner that is spaced apart by one super surface unit (21).

6. The 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna according to claim 1, characterized in that: The metal layer four (217) is a DC control circuit arranged on the back of the dielectric plate two (216), including periodically arranged shift register chips (2134), and the shift register chips (2134) are cascaded in pairs. The eight output ports of each shift register chip (2134) are respectively connected to the metallized through holes of two metasurface units (21), and the metallized through holes are metallized through holes arranged around the metasurface units (21); each output port of the shift register chip (2134) is connected in series with a resistor (2135); and the other three pins of the shift register chip (2134) are respectively connected to the three bias metal lines of the metal layer three (215) through three metallized blind holes.

7. The 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna according to claim 1, characterized in that: The linear polarization feed horn (1) comprises a coaxial waveguide converter (11), and the coaxial waveguide converter (11) is connected to the horn mouth (12) via a flange.

8. The 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna according to claim 2, characterized in that: The metasurface antenna supports dual-polarization working modes as follows: (1) When the feed polarization direction is +45°, the polarization direction of the metasurface antenna is also +45°, and the beam scanning depends on the switching state of the PIN diode 1 (2122) and the PIN diode 2 (2123) in each metasurface unit (21); (2) When the feed polarization direction is -45° polarization, the polarization direction of the metasurface antenna is also -45° polarization, and the beam scanning depends on the switching state of the pin diode three (2124) and the pin diode four (2125) in each metasurface unit (21).

9. The 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna according to claim 2, characterized in that: The metasurface antenna supports dual circular polarization in the following working modes: (1) When the polarization direction of the feed source is y-polarization, if the +45° polarization reflection phase introduced by the switching state of pin diode 1 (2122) and pin diode 2 (2123) leads the -45° polarization reflection phase introduced by the switching state of pin diode 3 (2124) and pin diode 4 (2125) by 90°, the polarization mode of the metasurface antenna is right-hand circular polarization; if the +45° polarization reflection phase introduced by the switching state of pin diode 1 (2122) and pin diode 2 (2123) lags the -45° polarization reflection phase introduced by the switching state of pin diode 3 (2124) and pin diode 4 (2125) by 90°, the polarization mode of the metasurface antenna is left-hand circular polarization; (2) When the polarization direction of the feed source is x-polarization, if the +45° polarization reflection phase introduced by the switching state of pin diode 1 (2122) and pin diode 2 (2123) leads the -45° polarization reflection phase introduced by the switching state of pin diode 3 (2124) and pin diode 4 (2125) by 90°, then the polarization mode of the metasurface antenna is left-hand circular polarization; if the +45° polarization reflection phase introduced by the switching state of pin diode 1 (2122) and pin diode 2 (2123) lags the -45° polarization reflection phase introduced by the switching state of pin diode 3 (2124) and pin diode 4 (2125) by 90°, then the polarization mode of the metasurface antenna is right-hand circular polarization.

10. The 2-bit multi-polarization reconfigurable electrically controlled metasurface antenna according to claim 8 or 9, characterized in that: The reflection phase that needs to be compensated for each metasurface unit (21) satisfies the following formula: in, represents the reflection phase required by the (m,n)th metasurface unit (21), k represents the free space wave number, r fmn represents the distance between the (m,n)th metasurface unit (21) and the feed phase center, r f represents the distance between the phase center of the feed source and the center of the reflective metasurface (2), represents the unit vector of the metasurface antenna beam pointing direction, represents the position vector of the (m,n)th hypersurface unit (21), Indicates the introduced reference phase; The switching states of the four pin diodes are calculated according to the compensated reflection phase formula (1) and the following formula (2): in, represents the phase required to be compensated for each metasurface unit (21) in the reflective metasurface (2) calculated by formula (1).

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