Low-power-consumption integrated beam scanning antenna based on programmable metasurface

Abstract

The invention discloses a low-power-consumption integrated beam scanning antenna based on a programmable metasurface, which is formed by arranging m * n metasurface antenna units, and the metasurface antenna units can perform 2-bit phase regulation and control, the unit comprises a top-layer patch, a first-layer dielectric substrate, a direct-current bias layer, a PP layer, a metal floor, a second-layer dielectric substrate and a feed transmission line which are stacked in sequence, the top-layer patch comprises an extension branch knot, a slotted square ring patch and an internally nested square patch, and the extension branch knot is arranged on one side of a non-slotted side of the slotted square ring patch; the extension branch knot, the square patch and the slotted square ring patch are connected through radio frequency switches; the direct current bias layer provides direct current bias voltage for the radio frequency switch; the feed transmission line is used for realizing radio frequency energy transmission. The antenna provided by the invention can realize a good beam scanning effect under the conditions of low power consumption and high integration level, and is expected to be further applied to the fields of space-air-ground integrated communication, Internet of Things and the like.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of electromagnetic super surfaces and antennas, in particular to a low-power integrated beam scanning antenna based on a programmable super surface. BACKGROUND

[0002] With the rapid development of space-air-ground integrated communication, the Internet of Things, satellite navigation and the new generation of mobile communication systems, wireless communication systems have higher requirements for the beam reconfigurability and system integration of antennas. Beam scanning antennas play an important role in realizing directional coverage, user tracking and anti-interference. Traditional beam scanning antennas mainly include mechanical scanning antennas, phased array antennas and dielectric lens antennas. Among them, mechanical scanning antennas rely on physical rotation to realize beam pointing change, and have complex structure and slow response speed, which is difficult to adapt to high-speed dynamic communication scenarios; the phased array antenna adopts electronic scanning, and has fast scanning speed and excellent performance, but its feed network is complex, the system cost is high and the power consumption is large, which limits its popularization in low-cost and low-power application scenarios; the scheme combining dielectric lens and phased array improves the beam scanning capability to a certain extent, but still has problems such as large profile height and limited system integration. SUMMARY

[0003] The application aims to provide a low-power integrated beam scanning antenna based on a programmable super surface.

[0004] The antenna comprises m*n programmable super surface antenna units, each unit comprising: a top layer patch, a first dielectric substrate, a direct current bias layer, a PP layer, a metal ground plate, a second dielectric substrate and a feed layer stacked in sequence from top to bottom; the top layer patch adopts a slotted square ring nested structure, comprising an extended branch, a slotted square ring patch and an internally nested square patch, the extended branch is arranged on one side of the non-slotted side of the slotted square ring patch, the extended branch and the slotted square ring patch are connected through a radio frequency switch, and the square patch and the slotted square ring patch are connected through two radio frequency switches.

[0005] The direct current bias layer is connected with the extended branch and the slotted square ring patch through the first metallized via hole to provide a direct current bias voltage for the radio frequency switch; the feed layer is connected with the square patch through the second metallized via hole to realize radio frequency energy transmission.

[0006] Further, the slotted square ring patch is provided with a slot extending along the x-axis direction at the center position, the slot divides the slotted square ring patch into symmetrical upper and lower parts, and the extended branch is arranged on one side of the slotted square ring and parallel to the slot direction.

[0007] Further, the two radio frequency switches connecting the upper and lower parts of the slit square ring patch with the square patch are in reverse connection state, the negative pole of the switch is connected to the square patch, and the positive pole of the switch is connected with the slit square ring.

[0008] Further, the DC bias layer includes three DC bias lines, each of which is loaded with a sector-shaped capacitor, the first metallized via has three, one of which is connected to the extension branch, and the other two are connected to the upper and lower parts of the slit square ring patch respectively; the three first metallized vias penetrate through the first dielectric substrate, and the bottom ends are connected to the center of the sector-shaped capacitor.

[0009] Further, the center of the metal floor is provided with a circular groove, the radius of the circular groove is greater than the radius of the second metallized via, and the second metallized via penetrates through the groove.

[0010] Further, the feed layer includes a feed transmission line, which is composed of a bending transmission line and a straight transmission line connected to the metallized via, and the feed transmission line is connected to the square patch and maintains DC connection with the negative pole of the two radio frequency switches.

[0011] Further, the extension branch is connected to the positive pole of the radio frequency switch, and the negative pole of the radio frequency switch is connected to the slit square ring patch.

[0012] Further, by controlling the on / off combination of the three radio frequency switches, the metasurface antenna unit has four radiation phase states of 0°, 90°, 180° and 270°.

[0013] Further, the first dielectric substrate and the second dielectric substrate are both F4BTM350 high frequency boards, and the PP layer is WL-PP350 semi-cured sheet.

[0014] Further, the preparation process of the antenna adopts planar printing technology.

[0015] Beneficial effects: Compared with the prior art, the significant technical effects of the present application are: (1) by introducing a slotted square ring nested structure and an extended branch in the unit radiation layer, 2-bit radiation phase control is realized using only a small amount of low-power switches, the structure is simple and the manufacturing cost is low; (2) the use of low-power radio frequency switch devices significantly reduces the overall power consumption of the metasurface antenna in the working state, making it suitable for low-power communication scenarios; (3) the series feeding network composed of the bending type and the straight line type transmission line compensates for the phase delay of the traveling wave, effectively reduces the sidelobe level and improves the beam scanning accuracy; (4) the programmable metasurface antenna has the advantages of low profile and easy integration; overall, the programmable metasurface antenna proposed in the present application can realize good beam scanning effect under the conditions of low power consumption and high integration, providing high-quality communication links for mobile users and providing a reference for the application of metasurface antennas in space-ground integration communication, Internet of Things and satellite navigation and other fields. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A low-power integrated beam scanning antenna based on a programmable metasurface is provided in the present application.

[0017] Figure 2 A unit structure of the metasurface antenna of the present application is shown in the figure; (a) is a unit front view; (b) is a unit top patch; (c) is a unit DC bias layer; (d) is a unit metal ground layer; (e) is a unit feed layer.

[0018] Figure 3 The top patch electric field distribution diagrams of the metasurface antenna unit in four states are shown in the figure; (a) is the electric field distribution diagram in the "110" state; (b) is the electric field distribution diagram in the "001" state; (c) is the electric field distribution diagram in the "101" state; (d) is the electric field distribution diagram in the "010" state.

[0019] Figure 4 The simulation curve diagrams of the metasurface antenna unit in four switch states in the embodiment of the present application are shown in the figure; (a) is the four radiation phase states corresponding to the metasurface, and (b) is the feed port reflection coefficient.

[0020] Figure 5 The metasurface antenna in the embodiment of the present application is shown in the figure.

[0021] Figure 6 The simulation normalized radiation pattern of the metasurface beam scanning in the embodiment of the present application is shown in the figure.

[0022] Figure 7It is a simulation result comparison chart of beam scanning effect before and after the bending of the super surface feed transmission line in the embodiment of the application; wherein, (a) is a 0° scanning effect comparison chart; (b) is a 15° scanning effect comparison chart; (c) is a 30° scanning effect comparison chart.

[0023] Figure 8 It is a programmable super surface antenna physical diagram and a programmable voltage control module schematic diagram in the embodiment of the application, wherein, (a) is a programmable super surface physical diagram, (b) is a programmable voltage control module;

[0024] Figure 9 It is a far field test result schematic diagram of the super surface antenna in the embodiment of the application; wherein, (a) is a normalized radiation pattern, (b) is a gain curve.

[0025] Figure 10 It is a power consumption test experiment scene and test result schematic diagram of the programmable super surface antenna. DETAILED DESCRIPTION

[0026] The application will be further described below in combination with specific embodiments and the accompanying drawings of the specification.

[0027] The programmable super surface is an artificial electromagnetic structure composed of subwavelength units, which can flexibly control the phase, amplitude and polarization characteristics of electromagnetic waves in a two-dimensional plane in cooperation with a voltage driving module, realize polarization conversion, electromagnetic focusing, multi-beam generation and radar scattering cross section reduction and other functions. At the same time, due to its two-dimensional plane structure characteristics, the programmable super surface has a very low profile and high integration. Therefore, based on the advantages and characteristics of the above programmable super surface, the programmable super surface antenna designed based on the above programmable super surface can realize good beam dynamic regulation function, and can replace the traditional beam scanning antenna.

[0028] The scheme proposed in the specific embodiments described herein is to design a programmable super surface based beam scanning antenna, which realizes dynamic beam scanning by driving the super surface through a voltage driving module, and the antenna structure design is simple, the feed network and DC bias network have low complexity, and has a low cost advantage.

[0029] As shown in Figure 1 The low-power integrated beam scanning antenna based on the programmable super surface according to the application is composed of m*n programmable super surface antenna units, and the preparation process adopts a planar printing technology, which has a relatively low cost.

[0030] As shown in Figure 2As shown in Figure (a), this embodiment provides a 2-bit programmable metasurface antenna unit, which has a multi-layer stacked structure. From top to bottom, it includes a top patch 1, a first dielectric substrate 6, a DC bias layer, a PP layer 9, a metal ground plane 10, a second dielectric substrate 11, and a feed layer. The structure is formed by laminating the first dielectric substrate 6 and the second dielectric substrate 11, with an overall thickness of approximately 2.2 mm. Both the first dielectric substrate 6 and the second dielectric substrate 11 are made of F4BTM350 material, with a relative permittivity of 3.5 and a loss tangent of 0.0025. The thickness of the first dielectric substrate 6 is 1.524 mm, and the thickness of the second dielectric substrate 11 is 0.508 mm. The PP layer 9 is a WL-PP350 prepreg with a thickness of 0.2 mm, a relative permittivity of 3.5, and a loss tangent of 0.0042. The DC bias layer and the metal ground plane 10 are bonded together using the WL-PP350 prepreg.

[0031] like Figure 2 In (a) and (b), the top layer patch 1 of the metasurface antenna element of the present invention adopts a slotted square ring nested structure to improve the tunability of the element's electromagnetic response. Specifically, the top layer patch 1 is composed of an extension branch 2, a slotted square ring patch 3, and an inner nested square patch 5. The slotted square ring patch 3 has a slot extending along the x-axis at its center, which divides the slotted square ring patch 3 into two symmetrical upper and lower parts; the extension branch 2 is located above the slotted square ring and is parallel to the direction of the slot. The extension branch 2, the square patch 5, and the slotted square ring patch 3 are all connected by the same type of low-power radio frequency switch 4. Specifically, the radio frequency switches 16 and 17 connecting the slotted square ring patch 3 and the square patch 5 are in reverse connection, with the negative terminal of the switch connected to the square patch 5 and the positive terminal of the switch connected to the slotted square ring 3; the extension branch is connected to the positive terminal of the radio frequency switch 15, and the negative terminal of the radio frequency switch 15 is connected to the slotted square ring patch 3.

[0032] The top surface mount 1 is connected to the DC bias layer via three first metallized vias 13, providing DC bias voltages to the three RF switches 15, 16, and 17 respectively. For example... Figure 2As shown in (a) and (c), one of the metalized through holes 13 has its top end connected to the extended branch 2, and the other two have their top ends connected to the upper and lower parts of the split square loop patch 3, respectively; three first metalized through holes 13 pass through the first dielectric substrate 6, and their bottom ends are connected to the center of the sector capacitor 8 loaded on the DC bias line 7. The sector capacitor 8 serves as a filter capacitor to achieve RF energy isolation between the DC bias line 7 and the metalized through hole 13. The second metalized through hole 14 passes through each stack layer, and its top end is connected to the square patch 5, and its bottom end is connected to the feed layer, achieving RF energy transmission from the feed layer to the top layer patch 1. The feed layer simultaneously serves as a DC ground, and the negative poles of the RF switches 16 and 17 connected to the square patch maintain DC connection.

[0033] As shown in (a) and (d), a circular groove 18 is provided at the center of the metal floor 10, and the radius of the circular groove 18 is slightly larger than the radius of the metalized through hole 14, so that the second metalized through hole 14 can pass through the metal floor 10 in a non-contact manner, avoiding RF energy leakage and ensuring RF energy transmission effect. Figure 2 As shown in (e), the feed layer includes a feed transmission line 12 composed of a bent transmission line and a straight transmission line connected to the second metalized through hole 14.

[0034] Figure 2 As shown in (e), the feed layer includes a feed transmission line 12 composed of a bent transmission line and a straight transmission line connected to the second metalized through hole 14.

[0035] The RF switch in the specific embodiment of the present application is preferably a low-power CMOS process RF switch of model ARW3172. By applying different DC bias voltages to each RF switch 4, the on / off state of the RF switch 4 is switched to change the equivalent current path of the top layer patch 1, thereby changing the electromagnetic response state of the metasurface antenna unit. In the embodiment of the present application, the RF switch 4 is coded as "1" when it is in the on state, and as "0" when it is in the off state. By configuring the on / off combination of the RF switch 4, four different coding states can be obtained, corresponding to the radiation phases of 0°, 90°, 180° and 270° of the metasurface antenna unit, respectively, to realize 2-bit phase control.

[0036] Figure 3 is the unit electric field distribution diagram of the metasurface antenna unit in the four coding states in the embodiment of the present application, and the specific frequency point is 5.9 GHz. The electric field distribution of the top layer patch 1 shows significant differences under different codes, and the electric field distribution difference directly affects the effective current path of the top layer patch 1, thereby corresponding to different radiation phases. Specifically, by combining the 180° phase control and 90° phase control of the unit, 2-bit phase control is realized. Figure 3 ​In (a) and (c), the 180° phase control is shown, in the coding "110" and "101", the radio frequency switch 15 remains in the on state, and the radio frequency switch 16 and the radio frequency switch 17 are in the opposite on / off state. When the state of the radio frequency switch 16 and the radio frequency switch 17 is reversed, the electric field of the slotted square ring nested structure presents a mirror distribution, and the current direction is reversed, thereby causing the radiation phase difference of the two coding combinations to be 180°. Similarly, in the coding "001" and "010" shown in (b) and (d), the radio frequency switch 15 remains in the off state, and the on / off state of the radio frequency switch 16 and the radio frequency switch 17 is exchanged to achieve 180° phase reversal. Further, the working mechanism of 90° phase control is: the extension branch along the x-axis direction is connected with the upper half of the slotted square ring patch 3 through the radio frequency switch 15, and by controlling the working state of the radio frequency switch 15, the effective current path can be further adjusted, thereby introducing a phase difference of 90° on the basis of 180° phase control, and realizing more precise phase control. As shown in (a) and (b), in the coding "110" and "001", due to the switching of the working state of the radio frequency switch 15, the electric field distribution at the radio frequency switch 15 changes, breaking the phase reversal between "110" and "101", so that the radiation phase difference corresponding to the two encodings is adjusted to 90°. As described above, by reasonably arranging the on / off state of the three groups of radio frequency switches, the 2-bit radiation phase (0°, 90°, 180°, 270°) control of the unit is successfully realized. In the design scheme, the unit only loads three radio frequency switches in the top patch structure, compared with other 2-bit beam scanning antennas, this phase control scheme has lower manufacturing cost and is easy to integrate with the system. Figure 3 Figure 3 In (a) and (b), in the coding "110" and "001", due to the switching of the working state of the radio frequency switch 15, the electric field distribution at the radio frequency switch 15 changes, breaking the phase reversal between "110" and "101", so that the radiation phase difference corresponding to the two encodings is adjusted to 90°. As described above, by reasonably arranging the on / off state of the three groups of radio frequency switches, the 2-bit radiation phase (0°, 90°, 180°, 270°) control of the unit is successfully realized. In the design scheme, the unit only loads three radio frequency switches in the top patch structure, compared with other 2-bit beam scanning antennas, this phase control scheme has lower manufacturing cost and is easy to integrate with the system.

[0037] In the specific embodiments of the present application, in order to ensure that the electromagnetic response of the metasurface antenna unit meets the design expectation, the three-dimensional electromagnetic simulation software CST Microwave Studio (CST) is used to optimize the design of the proposed metasurface antenna unit. Figure 4 The simulation results of the unit are shown, from Figure 4 In (a) and (b), in the coding "110" and "001", due to the switching of the working state of the radio frequency switch 15, the electric field distribution at the radio frequency switch 15 changes, breaking the phase reversal between "110" and "101", so that the radiation phase difference corresponding to the two encodings is adjusted to 90°. As described above, by reasonably arranging the on / off state of the three groups of radio frequency switches, the 2-bit radiation phase (0°, 90°, 180°, 270°) control of the unit is successfully realized. In the design scheme, the unit only loads three radio frequency switches in the top patch structure, compared with other 2-bit beam scanning antennas, this phase control scheme has lower manufacturing cost and is easy to integrate with the system. Figure 4 ​The reflection amplitude curve in the middle (b) can be seen, taking the reflection less than -10 dB as the standard, the impedance bandwidth of the unit covers 5.5 GHz to 6.5 GHz. This shows that the metasurface antenna unit proposed in the embodiment of the application can maintain a low reflection loss in the 2-bit phase control operating frequency band, ensuring that it has good radiation efficiency and stability in actual application. In summary, the designed metasurface antenna unit has stable impedance matching capability in the 5.5~6.5 GHz frequency band, and realizes accurate 2-bit radiation phase control in the 5.8~6.0 GHz range, laying a key foundation for the beam scanning function.

[0038] Figure 5 The beam scanning antenna structure based on the programmable metasurface in the embodiment of the application is shown, and the metasurface antenna is composed of 2x10 units. In order to simplify the voltage driving circuit, the metasurface antenna in the embodiment of the application adopts column control mode, that is, each column of units is connected in parallel and controlled by the same voltage control signal. It should be noted that the direct current bias line 7 described in the application is not limited to the column parallel connection mode. The direct current bias line 7 is changed to be independently connected with each metasurface antenna unit, which can provide mutually isolated bias voltage for the corresponding metasurface antenna unit, thereby realizing independent control of the electromagnetic response phase of each metasurface antenna unit. For a programmable metasurface array adopting column control mode, each column of units maintains the same state, which can be regarded as a uniform 10-element linear array. Assuming that each unit is an ideal point source, if the relative phase difference between adjacent units is equal and is denoted as When each unit is arranged at equal intervals , the antenna array beam pointing direction is , the spatial wave path difference between adjacent units in the direction is , and is:

[0039] (1)

[0040] wherein, is the phase constant of the wave in free space, is the wavelength of the electromagnetic wave in free space. Then, the phase of the th unit can be represented as :

[0041] (2)

[0042] wherein, is the reference phase of the starting unit of the array, is the linear phase distribution of the traveling wave on the transmission line at the th unit due to series sequential feeding, and then the phase of the Phase compensation required for each unit for:

[0043] (3)

[0044] To map the theoretical phase compensation value to the 2-bit encoding of the unit, it is necessary to... The quantification process is performed, as shown in equation (4):

[0045] (4)

[0046] in, This is a phase encoding matrix, where 0 corresponds to 0° phase, 1 corresponds to 90°, 2 corresponds to 180°, and 3 corresponds to 270°.

[0047] As can be seen from equation (2), the element spacing of a metasurface antenna affects the spatial energy distribution of the radiated beam. If the design is improper, a grating lobe with the same intensity as the main lobe may appear outside the expected main lobe direction, resulting in a waste of spatial energy distribution. To address this, if the antenna's scanning range needs to cover [−90°, 90°], the condition to avoid grating lobe formation is that the spacing d between adjacent antenna elements is less than half of the shortest operating wavelength.

[0048] like Figure 5 The metasurface antenna in the embodiment of the present invention shown employs a series-feed network with bent transmission lines. The bent portion 18 of the transmission line is equivalent to a phase delay line, and its main function is to compensate for the phase delay from the feed port to each element during traveling wave propagation. This design ensures that the excitation phase of each element in the array is consistent, thereby improving the beam control accuracy of the antenna array. Specifically, it is assumed that the reference phase of the first element is... Then the first Excitation phase of each unit for:

[0049] (5)

[0050] in, The length of the bent transmission line between adjacent unit feed points. Let be the phase constant on the transmission line. Let be the relative permittivity of the dielectric substrate. The compensation target can be calculated using equation (5): , required , where d is the interval between adjacent units and L is the length of the bend in the transmission line 18.

[0051] In the embodiment of the present application, in order to realize multi-angle beam scanning, first, the phase compensation matrix required for a certain beam pointing is calculated according to formulas (1)-(3), then the quantization processing is performed by using formula (4) and corresponding to 2-bit coding, and finally the phase coding matrix required for the super surface antenna beam pointing to the angle is obtained. Figure 6 The simulation results of the normalized far-field pattern of the 2x10 super surface antenna proposed in the embodiment show that, at 5.9 GHz, the simulation and the theoretical expectation are basically consistent within the scanning range of ±45°, and the scanning angle error is within ±2°. In addition, within the scanning angle range of 0° to ±30°, the sidelobe level is less than -10 dB, and the sidelobe level at other angles is maintained below -8 dB, which preliminarily verifies the single-beam scanning capability of the programmable super surface antenna in the embodiment.

[0052] Figure 7 The beam scanning effects before and after the bending of the feed transmission line of the super surface antenna in the embodiment of the present application are compared. In the legend,'straight' represents that the transmission line remains linear, and 'bent' represents that the transmission line is bent. Figure 7 The simulation results in Figs. 16(a)-16(c) show that, compared with the straight feed transmission line, after bending, the sidelobe level is reduced by more than 3 dB at three typical angles of 0°, 15° and 30°, and the beam pointing angle deviation is reduced by about 2° at the direction of 15°. This comparison result proves the effectiveness of the feed transmission line bending design, which can compensate for the phase delay caused by the traveling wave on the transmission line, thereby optimizing the beam scanning performance of the antenna.

[0053] Figure 8 The physical diagram of the programmable super surface antenna designed according to the foregoing in the embodiment of the present application and the voltage driving module schematic diagram are shown in Figs. 18(a) and 18(b). The super surface sample is made of a planar printed circuit board technology, and the overall size of the finally prepared sample is 80 mm x 350 mm. Figure 8 In Fig. 18(a), the front view and the back view of the super surface sample are shown. At the welding position of the radio frequency coaxial connector, a groove processing is performed to improve the radio frequency grounding effect. The direct current bias lines 7 of each column of units extend to the bottom end of the array and are connected to the FPC socket on the back of the array through metal through holes. At the same time, since the feed transmission line 12 also serves as a direct current ground, the two direct current bias lines 20 connect the transmission lines at both ends to the FPC socket, and a sector capacitor 21 is used as a filter capacitor, so as to isolate the radio frequency signal and the direct current signal. Figure 8 As shown in Fig. 18(b), the voltage driving module 22 used in the embodiment of the present application has a total of 30 effective output pins, and every three pin pairs correspond to the positive electrode of three groups of radio frequency switches of one column of units, so that 10 columns of units can be independently controlled.

[0054] Figure 9 The far-field beam scanning test results of the programmable super surface antenna in the embodiment of the present application are shown in Figs. 19(a)-19(c). Figure 9The middle (a) shows the radiation patterns of the metasurface antenna in the range of ±45°, with beam scanning at intervals of 15°. The test results are basically consistent with the simulation and theoretical calculation, with an error of within ±2°, and the sidelobe level is always less than -8 dB, verifying the single-beam scanning capability of the metasurface antenna. Figure 9 The middle (b) shows the measured gain curve and the simulation gain curve, and the trends are consistent. Although the measured radiation gain is attenuated compared with the simulation result, the maximum difference is less than 2 dB. The measured in-band peak gain is 13.7 dBi, and the minimum gain is 12.6 dBi, corresponding to the aperture efficiencies of 30% and 23.5%, respectively. Overall, the far-field test results in the microwave anechoic chamber prove that the programmable metasurface antenna in the embodiment has good performance in terms of beam scanning and gain stability.

[0055] Figure 10 The test experiment scene of the power consumption of the metasurface antenna in the embodiment is shown. In the test process, a direct-current stabilized power supply is used to provide a direct-current bias voltage for the radio frequency switch, and the direct-current stabilized power supply is used to monitor and display the output voltage and current parameters in real time. The test results show that when only one radio frequency switch is in the on state, the corresponding power consumption of the metasurface antenna is 1.12 mW. For the metasurface antenna proposed in the embodiment, the number of radio frequency switches in the on state is at most 2x20 in the normal working state, and accordingly the maximum power consumption of the antenna is about 45.3 mW. It can be seen that the metasurface antenna proposed in the embodiment keeps the overall power consumption at a low level while realizing the beam scanning function.

Claims

1. A low-power integrated beam scanning antenna based on a programmable metasurface, characterized in that, The antenna comprises m×n programmable metasurface antenna elements. Each element includes: a top layer patch (1), a first dielectric substrate (6), a DC bias layer, a PP layer (9), a metal ground plane (10), a second dielectric substrate (11), and a feed layer stacked from top to bottom. The top layer patch adopts a slotted square ring nested structure, including an extension branch (2), a slotted square ring patch (3), and an internally nested square patch (5). The extension branch is located on one side of the non-slotted edge of the slotted square ring patch. The extension branch and the slotted square ring patch are connected by an RF switch, and the square patch and the slotted square ring patch are connected by two RF switches. The DC bias layer is connected to the extended stub and the slotted square ring patch through a first metallized via (13) to provide DC bias voltage to the RF switch (4); the feed layer is connected to the square patch (5) through a second metallized via (14) to realize RF energy transmission.

2. The antenna according to claim 1, characterized in that, The center of the slit square ring patch (3) has a slit extending along the x-axis, which divides the slit square ring patch (3) into two symmetrical upper and lower parts; the extension branch (2) is located on one side of the slit square ring and is parallel to the direction of the slit.

3. The antenna according to claim 2, characterized in that, The two radio frequency switches connected between the upper and lower parts of the slotted square ring patch (3) and the square patch (5) are in reverse connection state. The negative terminal of the switch is connected to the square patch (5), and the positive terminal of the switch is connected to the slotted square ring (3).

4. The antenna according to claim 1, characterized in that, The DC bias layer includes three DC bias lines (7), each DC bias line is loaded with a fan-shaped capacitor (8), and there are three first metallized vias (13), one of which is connected to an extension branch (2) at its top end, and the other two are connected to the upper and lower parts of the slotted square ring patch (3) at their top ends respectively; the three first metallized vias (13) penetrate the first dielectric substrate (6), and their bottom ends are all connected to the center of the fan-shaped capacitor (8).

5. The antenna according to claim 1, characterized in that, The metal floor (10) has a circular groove (18) at its center. The radius of the circular groove is larger than the radius of the second metallized through hole (14). The second metallized through hole (14) passes through this groove.

6. The antenna according to claim 1, characterized in that, The feed layer includes a feed transmission line (12), which is composed of a bent transmission line and a straight transmission line connected to the metallized via (14); the feed transmission line (12) also serves as DC ground and maintains DC connection with the negative terminals of the two RF switches connected to the square patch (5).

7. The antenna according to claim 1, characterized in that, The extended branch (2) is connected to the positive terminal of the radio frequency switch, and the negative terminal of the radio frequency switch is connected to the slotted square ring patch (3).

8. The antenna according to claim 1, characterized in that, By controlling the on / off combination of the three radio frequency switches (4), the metasurface antenna element has four radiation phase states: 0°, 90°, 180°, and 270°.

9. The antenna according to claim 1, characterized in that, The first dielectric substrate (6) and the second dielectric substrate (11) are both F4BTM350 high-frequency boards, and the PP layer (9) is a WL-PP350 prepreg.

10. The antenna according to claim 1, characterized in that, The antenna is manufactured using planar printing technology.

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