Metasurface array antenna with independently adjustable amplitude and phase

Abstract

The invention discloses a metasurface array antenna with independently adjustable amplitude and phase. Aiming at the problems of serious amplitude and phase regulation coupling and low precision of the existing metasurface antenna, the invention provides an amplitude and phase independent adjustable unit formed by cascading a reflective attenuator, a reflective phase shifter and a 1-bit reconfigurable radiation structure. The attenuator adopts a PIN diode, continuous amplitude regulation and control from-1.5 dB to-25dB are realized, and the phase fluctuation is less than + / -5 degrees; the phase shifter adopts a variable capacitance diode to realize 4-bit (16-state) phase regulation and control, and is cascaded with the 1-bit phase of the radiation structure to form 5-bit (32-state) phase regulation and control, the coverage is 0-360 degrees, and the stepping is 11.25 degrees. Amplitude and phase are regulated independently and do not interfere with each other. A 1 * 8 array and a one-to-eight Wilkinson power divider are integrated, the overall profile is only 0.03 lambda 0, and the antenna has the advantages of being high in precision, wide in range, low in profile, low in cost and the like and is suitable for 5G / 6G communication, radar detection and beam forming systems.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication and antenna technology, specifically relating to an amplitude and phase independently tunable array antenna based on a reconfigurable metasurface. Background Technology

[0002] With the rapid development of technologies such as 5G / 6G communication, radar detection, and satellite communication, higher demands are being placed on antenna performance. Traditional phased array antennas rely on T / R components to achieve beam control, which suffers from problems such as high cost, high power consumption, and large size.

[0003] In recent years, reconfigurable metasurface technology has attracted widespread attention due to its advantages such as low profile, low cost, and low power consumption. Existing technologies mainly fall into two categories:

[0004] 1. Pure phase-reconfigurable metasurface: Dynamic control of unit phase is achieved through PIN diodes or varactor diodes, enabling beam scanning. However, the amplitude cannot be independently controlled, resulting in high sidelobe levels (typically only around -13dB) and limited beamforming capability.

[0005] 2. Amplitude and phase combined control scheme: A few studies have attempted to control amplitude and phase simultaneously, but there are problems such as high control complexity, severe amplitude and phase coupling, and difficulty in independent control, which cannot achieve precise beamforming.

[0006] Therefore, there is an urgent need for a high-performance antenna array hardware structure that can achieve independent, precise, and continuous amplitude and phase control.

[0007] Purpose of the invention

[0008] The present invention aims to provide a design method for a metasurface array antenna with independent amplitude and phase control, in order to solve the technical problems of severe amplitude and phase coupling, insufficient control accuracy, and difficulty in achieving complex beamforming in the prior art.

[0009] Technical solution

[0010] 1. Overall Structure

[0011] An amplitude- and phase-independently tunable metasurface array antenna, comprising:

[0012] Multiple antenna elements are arranged in an array according to a certain pattern (e.g., 1×8, with the element spacing set to half a wavelength).

[0013] A feed network, connected to each antenna element, is used to distribute radio frequency signals; the preferred feed network uses a 1-to-8 Wilkinson power divider to provide equal-amplitude and in-phase excitation to the eight antenna elements.

[0014] A DC bias network is connected to each antenna element and is used to independently control the operating state of each element.

[0015] Its characteristic is that each antenna element has the following structure: Figure 13 As shown, it includes:

[0016] Radiation structure, used to convert guided waves into space waves;

[0017] A reflective phase shifter, connected to the radiating structure, is used to independently adjust the phase of the signal;

[0018] A reflective attenuator is connected between the feed network and the reflective phase shifter to independently control the amplitude of the signal.

[0019] A reflective attenuator and a reflective phase shifter are cascaded together to achieve independent control of amplitude and phase.

[0020] 2. Specific structure of the reflective attenuator

[0021] The reflective attenuator, such as Figure 11 As shown, it includes:

[0022] A 3dB directional coupler with an input port (Port1), an output port (Port2), a through port (Port3), and a coupling port (Port4).

[0023] Two PIN diodes are respectively loaded at the through port and the coupling port as reflective loads;

[0024] A DC bias circuit, connected to the PIN diode, is used to independently control its bias voltage;

[0025] By adjusting the bias voltage of the PIN diode, its equivalent resistance value is changed, thereby adjusting the amplitude of the reflection coefficient and achieving continuous control of the radio frequency signal amplitude.

[0026] Under different bias voltage conditions, the insertion loss of the attenuator can be continuously adjusted from -1.5dB to -25dB, exhibiting a wide attenuation range. Furthermore, the transmission phase change is less than ±5° under different attenuation states, demonstrating good phase stability and achieving decoupled control of amplitude and phase.

[0027] 3. Specific structure of a reflective phase shifter

[0028] The reflective phase shifter, such as Figure 5 As shown, it includes:

[0029] A 3dB directional coupler with an input port (Port1), an output port (Port2), a through port (Port3), and a coupling port (Port4).

[0030] Two varactor diodes are respectively loaded at the through port and the coupling port as reflective loads;

[0031] A DC bias circuit, connected to the varactor diode, is used to independently control its bias voltage;

[0032] By adjusting the bias voltage of the varactor diode, its equivalent capacitance value is changed, thereby adjusting the phase of the reflection coefficient and achieving precise control of the radio frequency signal phase.

[0033] The phase shifter implements 4-bit phase quantization, with a total of 16 phase states, a phase step of 11.25°, and a phase shift range of 0° to 168.75°. Simultaneously, the insertion loss in all states is below -2dB, indicating that the phase shifter maintains good transmission performance while achieving a wide phase shift range.

[0034] 4. Specific implementation of the radial structure

[0035] The radiation structure is a 1-bit reconfigurable antenna element, such as... Figure 1 As shown, it includes:

[0036] A center-fed patch;

[0037] Two large symmetrically placed radiating patches are located on either side of the central patch;

[0038] Two PIN diodes are connected between the center patch and the two large patches on either side, respectively;

[0039] Two rows of grounding metal vias connect to the large patch panels on both sides;

[0040] PIN diodes exhibit low impedance when forward biased, equivalent to a conducting state; while they exhibit high impedance when reverse biased, equivalent to an off state. By adjusting the forward and reverse bias voltages of the PIN diodes, the antenna's frequency, radiation direction, and radiation mode can be flexibly controlled. By controlling the on / off states of the two PIN diodes, the current path direction can be changed, achieving two radiation phase states: 0° and 180°.

[0041] Implementation of 5.5-bit phase modulation

[0042] The reflective phase shifter (4-bit) and the radiating structure (1-bit) are cascaded together to achieve 5-bit phase control, i.e., 32 phase states, covering the full phase range of 0° to 360°, with a phase step of 11.25°.

[0043] 6. Realization of independent amplitude and phase control

[0044] The reflective attenuator (amplitude control) is cascaded with the 5-bit phase control unit (phase control) to achieve independent and continuous control of amplitude and phase.

[0045] Amplitude control: Continuous adjustment is achieved by changing the bias voltage of the PIN diode in the attenuator;

[0046] Phase control: 5-bit precise control is achieved by changing the bias voltage of the varactor diode in the phase shifter;

[0047] The two do not affect each other, achieving orthogonal amplitude and phase control.

[0048] 7. Unit size

[0049] Each antenna element has an overall size of 60mm×30mm×1.827mm, corresponding to 1λ0×0.5λ0×0.03λ0 at 5GHz, with a profile height of only 0.03λ0, exhibiting low profile characteristics.

[0050] Beneficial effects

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] 1. By cascading a reflective attenuator and a phase shifter, orthogonal control of amplitude and phase is achieved. When adjusting the amplitude, the phase remains basically unchanged, and when adjusting the phase, the amplitude remains basically unchanged, and the degree of control freedom is greatly improved.

[0053] 2. By cascading a 1-bit radiation unit with a 4-bit phase shifter, high-precision 5-bit (32 states) phase control is achieved, with a phase step of 11.25°, covering the full phase range of 0° to 360°.

[0054] 3. The reflective attenuator achieves continuous amplitude control from -1.5dB to -25dB, with an adjustable range exceeding 20dB, and exhibits good phase stability.

[0055] 4. Integrated using multi-layer PCB technology, the overall size of the unit is... (exist Place Therefore, the antenna unit as a whole has a low profile. It does not require expensive T / R components, has low power consumption, and is suitable for large-scale deployment. Attached Figure Description

[0056] Figure 1 : Schematic diagram of a 1-bit reconfigurable antenna element structure, including (a) exploded view; (b) top view; (c) bottom view; Figure 2 : Surface current and equivalent magnetic current distribution of a 1-bit antenna element under different states, where (a) "#0" state; (b) "#1" state;

[0057] Figure 3 The reflection coefficient of a 1-bit reconfigurable antenna element; Figure 4 : Far-field electric field phase of a 1-bit reconfigurable antenna element; Figure 5 Schematic diagram of a 4-bit reflective phase shifter;

[0058] Figure 6 4-bit reflective phase shifter reflection coefficient S 11；

[0059] Figure 7 : Transmission characteristics of a 4-bit reflective phase shifter, where (a) transmission phase; (b) transmission amplitude; Figure 8 Schematic diagram of a 1-to-8 Wilkinson power divider; Figure 9 Simulation results of S-parameters of a 1-to-8 Wilkinson power divider;

[0060] Figure 10 : Schematic diagram of an amplitude-phase independently adjustable array structure, wherein (a) is a radiating patch layer; and (b) is a feed network layer; Figure 11 Schematic diagram of a reflective attenuator;

[0061] Figure 12 Simulation results of a reflective attenuator, where (a) the reflection coefficient S 11 (b) Transmission amplitude S 21 (dB); (c) Transmission phase S 21 (Deg.);

[0062] Figure 13 : Schematic diagram of a 5-bit amplitude and phase independently adjustable unit structure, wherein (a) top view; (b) bottom view; (c) exploded view;

[0063] Figure 14 Amplitude and phase modulator prototype;

[0064] Figure 15 : Amplitude attenuation performance test results, of which (a) reflection coefficient S 11 (b) Transmission characteristics S 21 ;

[0065] Figure 16 : Test results of the amplitude-phase adjustable unit, including (a) reflection coefficient; (b) transmission amplitude (dB); (c) transmission phase (Deg.).

[0066] Figure 17 Amplitude and phase state division diagram of amplitude-phase modulator. Detailed Implementation

[0067] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Embodiment: 1×8 Amplitude-Phase Adjustable Antenna Array

[0068] 1.1-bit reconfigurable antenna element design:

[0069] The designed 1-bit reconfigurable antenna element combines a PIN diode with the antenna's radiating structure, and controls the antenna's operating state by adjusting the current direction through the PIN diode. In terms of structural layout, the PIN diode and the radiating patch are located on the same plane, resulting in a compact overall structure that is beneficial for miniaturization and large-scale array integration design.

[0070] The overall structure of the designed 1-bit reconfigurable antenna element is as follows: Figure 1 As shown, this unit consists of four layers: a top dielectric layer (Substrate1), a ground plane (GND), a bonding layer (BondingLayer), and a bottom dielectric layer (Substrate2).

[0071] The dielectric substrate is Rogers 4003C with a relative permittivity of 3.55 and a loss tangent tanδ = 0.0027; the adhesive layer is h b =0.1mm thick prepreg Rogers 4450F ( (tanδ=0.004). The thicknesses of the top and bottom dielectric substrates are h1=1.524mm and h2=0.203mm, respectively. The overall unit size is 30×30×1.827mm. 3 (0.5λ0×0.5λ0×0.03λ0) 3 (λ0 is the wavelength in free space corresponding to 5 GHz), other detailed structural parameters are shown in Table 1.

[0072] The radiating structure at the top of the unit includes a pair of symmetrical large metal radiating patches and a small metal patch in the center. Two rows of grounding metal vias on the outer sides act as metal walls to achieve good grounding. Two MADP-000907-14020W type PIN diodes are connected to the large and small metal patches. By controlling the switching state of the PIN diodes, currents are generated in opposite directions, thereby affecting the phase of the far field.

[0073] This structure is equivalent to a magnetic dipole, forming a loop current between the feed pillar, the radiating patch, the metal via, and the ground plane, and radiating into space perpendicular to the patch. A 50-ohm microstrip line is placed at the bottom of the unit, which feeds the front patch through the metal pillar under impedance matching conditions.

[0074] Assume that encoding state "#0" corresponds to PIN 1 being on and PIN 2 being off; state "#1" corresponds to PIN 1 being off and PIN 2 being on. Table 2 shows the operating states, bias voltages, and relative phases of the radiation fields of the two PIN diodes under different encoding states. It can be seen that by adjusting the bias voltage of the PIN diodes, their switching states can be switched, thus achieving two phase responses: 0° and 180°. Figure 2 As shown, the directions of the surface current and equivalent magnetic current in state "#0" are opposite to those in state "#1", further verifying that the unit has the ability to achieve 1-bit phase modulation.

[0075] The simulation results of the 1-bit reconfigurable antenna element are analyzed below. Figure 3 The reflection coefficient of the antenna element in state "#0" and state "#1" As can be seen, the antenna exhibits good impedance matching characteristics in the 4.5GHz~5.2GHz range. Furthermore, the curves in the two states show a high degree of similarity, further verifying the symmetry of the antenna structure.

[0076] To verify the phase modulation capability of the 1-bit antenna, an electric field probe was added to the far field during the simulation. Figure 4 The far-field phase of the electric field is shown in two states, "#0" and "#1". It can be seen that the phase maintains a stable difference of about 180° over a wide frequency band.

[0077] 2. Phase shifter design:

[0078] Design a reflective phase shifter operating in the C-band, with the following structure: Figure 5 As shown. The dielectric substrate uses Rogers 4003C (ε) r =3.55, tanδ=0.0027), with a thickness of 0.203mm. Its specific geometric parameters are shown in Table 3. The entire phase shifter's input and output ports are matched to 50Ω to ensure impedance compatibility with other components. Furthermore, the phase shifter utilizes curved microstrip lines, better meeting miniaturization design requirements.

[0079] A MAVR-000120-1411 varactor diode was selected as the reflective load, whose capacitance value can be continuously varied between 0.14 pF and 1.1 pF with voltage. Specifically, two varactor diodes (Var1 and Var2) were connected to the load terminal and connected in series with a grounded microstrip line to introduce an inductive component, which together constitutes the impedance of the adjustable reflective load. By adjusting the bias voltage applied to the varactor diode, its equivalent capacitance value can be controlled, thereby obtaining 16 discrete phase states, achieving 4-bit phase quantization, and covering a phase shift range of approximately 168.75°.

[0080] In addition, a circuit was designed to reduce mutual interference between radio frequency signals and DC signals to ensure circuit stability. Two capacitors (C1 and C2) are connected in series at the input and output ports of the phase shifter to isolate the DC signal. The DC bias line consists of a high-frequency bypass capacitor C3 and a quarter-wavelength high-impedance line. The capacitance of all three capacitors, C1, C2, and C3, is 100pF.

[0081] The performance of a 4-bit reflective phase shifter was modeled and simulated in CST, such as... Figure 6 The figure shows the reflection coefficient S of the phase shifter. 11 For ease of illustration, only six states are shown in the figure. It can be seen that the impedance matching bandwidth of the overlapping portion is 4.4GHz to 5.2GHz, corresponding to a relative bandwidth of approximately 16%.

[0082] When the capacitance changes from 0.15pF to 0.59pF, the corresponding transmission phase and amplitude of the phase shifter are as follows: Figure 7 As shown.

[0083] Within the 5GHz center band, the phase shift of the phase shifter can be stabilized at 168.75°, meeting the design requirements of 4-bit phase quantization. Meanwhile, the insertion loss is below -2dB in all states, indicating that the phase shifter maintains good transmission performance while achieving a wide phase shift range.

[0084] Table 4 details the 16 coded states of the 4-bit reflective phase shifter, along with the corresponding varactor diode control voltage, capacitance value, and relative phase shift for each state. By adjusting the bias voltage of the varactor diode (0V~7.69V), its capacitance value can vary from 0.15pF to 0.59pF, thereby achieving a phase coverage of 0°~168.75° with a phase step of 11.25°.

[0085] 3. Power supply network:

[0086] To achieve uniform feeding of the 8-element antenna array, a design was developed. Figure 8 The 1-to-8 Wilkinson power divider with equal power distribution shown has the same material and thickness of the dielectric substrate as the feed network layer. Its specific structural parameters can be found in Table 5. Simulation results of the power divider are as follows: Figure 9 As shown, its reflection coefficient S 11 The insertion loss is below -10dB in the 4GHz to 6GHz range, indicating a wide operating bandwidth. At the center frequency of 5GHz, its insertion loss S... 21 The isolation level is -9.6dB, which meets the design requirements. Meanwhile, the isolation S between adjacent ports is... 32 At 5 GHz, it is -41 dB, demonstrating excellent port isolation performance.

[0087] The power divider is used as the feed network for the array antenna, providing equal-amplitude and in-phase excitation to each element. The antenna elements are then assembled into a 1×8 antenna array, the structure of which is as follows: Figure 10 As shown, the element spacing is set to half a wavelength, and the interlayer structure of the amplitude-phase independently adjustable units is continued. The thickness of the entire array is only 1.827 mm (0.03λ0), with a low profile, and the array area is expanded to 240 × 60 mm. 2 .

[0088] 4. Attenuator Design:

[0089] The designed attenuator uses a MADP-000907-14020W PIN diode at the end of a 3dB directional coupler as an adjustable device to control the amplitude of the reflection coefficient, thereby achieving the purpose of adjusting the amplitude of the radio frequency signal.

[0090] The structure of the attenuator is as follows Figure 11 As shown, the specific parameters are shown in Table 6. Two capacitors (C1 and C2) are connected in series at the input and output ports to isolate DC signals. The DC bias line consists of a grounded capacitor C3 and a high-impedance line representing one-quarter of the isolation wavelength. All three capacitors (C1, C2, and C3) are 100pF.

[0091] Figure 12 Simulation results show that the attenuator performs well in all operating states at 5 GHz, with a bandwidth of approximately 0.9 GHz. Under different bias voltage conditions, the insertion loss of the attenuator can be continuously adjusted from -1.5 dB to -25 dB, exhibiting a wide attenuation range. Meanwhile, the transmission phase change is small (less than ±5°) in all states, demonstrating good phase stability.

[0092] 5. Amplitude and phase independently adjustable array design:

[0093] By cascading an attenuator and a phase shifter, independent adjustment of amplitude and phase can be achieved. The overall unit structure is as follows: Figure 13 As shown, the overall dimensions of each antenna element are 60c × 30 × 1.827 mm. 3 (1λ0×0.5λ0×0.03λ0 at 5GHz), thus the antenna element has a low overall profile. The element consists of three layers: a radiating layer (Substrate1), a ground layer (GND), and a feed network layer (Substrate2). The dielectric substrate used is Rogers 4003C (ε... r =3.55, tanδ=0.0027), the layers are connected by Rogers 4450F (ε r=3.7, tanδ=0.004) are bonded together. The dimensions of the phase shifter and attenuator have been given above and will not be repeated here. Other dimensions are shown in Table 7.

[0094] 6. Test Results:

[0095] To verify the performance of the designed amplitude-phase independent modulation unit, an amplitude-phase modulation device (such as a phase shifter and an attenuator cascaded together) was fabricated. Figure 14 As shown in the figure, multiple sets of amplitude and phase adjustable performance tests were conducted. The reflection coefficient and transmission characteristics of the unit were tested using a Keysight N5230C vector network analyzer.

[0096] First, the performance of adjusting the unit amplitude under a fixed phase was verified. For example... Figure 15 As shown in (a), the overall matching performance of the unit is good under different voltage conditions, and its reflection coefficient remains below -10dB in a wide frequency band from 4.5GHz to 5.8GHz. Meanwhile, the transmission characteristics ( Figure 15 As can be seen in (b), the attenuation amplitude of the attenuator can be continuously adjusted within the range of -6.5dB to -27.1dB, with an adjustable range greater than 20dB. Since additional attenuation is introduced when the phase shifter and attenuator are cascaded, the overall attenuation amplitude of the cascaded structure is slightly increased compared to a single attenuator unit.

[0097] Subsequently, under a fixed amplitude condition, the phase shift variation under different control voltages was tested. For ease of demonstration, only the test results for some states are presented here. Figure 16 As shown in (a), when different bias voltages are applied to the varactor tubes in the phase shifter, the overlap of the bandwidth is approximately 4.8 GHz to 5.3 GHz. Figure 16 As shown in (b), the insertion loss of the entire unit is within -7dB, and the insertion loss changes little with the phase shifter voltage state. When the voltage controlling the varactor diode changes from 0V to 9V, the insertion loss is... Figure 16 As can be seen in (c), the phase shifter can produce a phase shift of approximately 176°.

[0098] To comprehensively evaluate the amplitude and phase modulation capabilities of the unit, a systematic test was conducted on the modulator's performance at 5 GHz. The experiment selected 16 phase states and 10 amplitude states, forming a total of 160 amplitude-phase combination states. For ease of demonstration, the phase and amplitude states were normalized: the phase was normalized to the 0°~180° range; the amplitude was normalized to a value of 1 with -6 dB as the normalization value, so -27 dB corresponds to 0.09. The test results are as follows: Figure 4-13As shown. Experimental results show that: with the adjustment of the varactor diode voltage, the phase can cover from 0° to 168.75°; with the change of the PIN diode bias voltage, the unit amplitude can be almost continuously adjusted within the normalized amplitude range of [0.09, 1]. Therefore, by selecting... Figure 17 The discrete point states that have already been measured are used to quantize the phase and amplitude.

[0099] Furthermore, it can be observed from the figure that the attenuator exhibits relatively small phase fluctuations under different amplitude states; similarly, the phase shifter shows relatively small amplitude fluctuations under different phase states. This verifies that the amplitude and phase controls have good independence.

[0100] Furthermore, by combining the amplitude-phase modulator with a 1-bit radiating patch antenna, the overall phase control range of the unit is expanded. Ultimately, its phase and normalized amplitude states can almost cover the entire region in the two-dimensional coordinate plane with the horizontal axis [-180°, 180°] and the vertical axis [0.09, 1]. Thus, the proposed hardware design achieves approximately continuous adjustable amplitude and phase, enabling the unit to flexibly adjust the radiated wavefront in different operating modes, providing ample design space and an experimental platform for subsequent optimization algorithms for array pattern synthesis.

[0101] Table 1 Specific parameters of the 1-bit reconfigurable antenna element

[0102]

[0103] Table 2 Operating Status of 1-bit Antenna Element

[0104]

[0105] Table 3 Specific parameters of 4-bit reflective phase shifter

[0106]

[0107] Table 4. Status Coding Table for 4-bit Reflective Phase Shifters

[0108] Table 5 Structural parameters of Wilkinson power divider

[0109]

[0110] Table 6 Attenuator Specific Parameters

[0111]

[0112] Table 7 Structural parameters of the amplitude-phase independently adjustable unit

[0113]

Claims

1. An amplitude and phase independently steerable metasurface array antenna comprising a plurality of antenna elements, a feed network and a DC bias network, characterized in that, Each antenna element includes: a radiating structure for converting guided waves into space waves; a reflective phase shifter connected to the radiating structure for independently controlling the phase of the signal; and a reflective attenuator connected between the feed network and the reflective phase shifter for independently controlling the amplitude of the signal. The reflective attenuator and the reflective phase shifter are cascaded to achieve independent control of amplitude and phase.

2. The amplitude and phase independently steerable metasurface array antenna according to claim 1, characterized in that, The reflective attenuator includes: a 3dB directional coupler having an input port, an output port, a through port, and a coupling port; two PIN diodes, respectively loaded at the through port and the coupling port as reflective loads; and a DC bias circuit connected to the PIN diodes for independently controlling their bias voltage. By adjusting the bias voltage of the PIN diodes, their equivalent resistance value is changed, thereby achieving continuous modulation of the RF signal amplitude.

3. The amplitude and phase independently steerable metasurface array antenna of claim 2, wherein, The reflective attenuator has an insertion loss that is continuously adjustable from -25dB to -1.5dB under different bias voltage conditions, and the transmission phase change under different attenuation states is less than ±5°.

4. The amplitude and phase independently steerable metasurface array antenna of claim 1, wherein, The reflective phase shifter includes: a 3dB directional coupler having an input port, an output port, a through port, and a coupling port; two varactor diodes, respectively loaded on the through port and the coupling port as reflective loads; and a DC bias circuit connected to the varactor diodes for independently controlling their bias voltage. By adjusting the bias voltage of the varactor diodes, their equivalent capacitance value is changed, thereby achieving phase modulation of the radio frequency signal.

5. The amplitude and phase independently steerable metasurface array antenna according to claim 4, characterized in that, The reflective phase shifter achieves 4-bit phase quantization with a total of 16 phase states, a phase step of 11.25°, a phase shift range of 0° to 168.75°, and an insertion loss of less than -2dB in all states.

6. The amplitude-phase independently tunable metasurface array antenna according to claim 1, characterized in that, The radiating structure is a 1-bit reconfigurable antenna element, comprising: a center-fed patch; two symmetrically placed large radiating patches located on both sides of the center-fed patch; two PIN diodes connected between the center-fed patch and the large radiating patches on both sides; two rows of grounding metal vias connected to the large radiating patches on both sides; by controlling the on / off state of the two PIN diodes, the current path direction is changed to achieve two radiation phase states of 0° and 180°.

7. The amplitude-phase independently adjustable metasurface array antenna according to any one of claims 1, 4, 5, and 6, characterized in that, The reflective phase shifter is cascaded with the radiating structure to achieve 5-bit phase control, i.e., 32 phase states, covering the full phase range from 0° to 360°, with a phase step of 11.25°.

8. The amplitude-phase independently tunable metasurface array antenna according to claim 1, characterized in that, The feeding network is a 1-to-8 Wilkinson power divider, used to provide equal amplitude and in-phase excitation to eight antenna elements; the multiple antenna elements are arranged in a 1×8 array, and the element spacing is set to half a wavelength.

9. The amplitude-phase independently tunable metasurface array antenna according to claim 1, characterized in that, The overall dimensions of the antenna element are 60mm×30mm×1.827mm, corresponding to 1λ0×0.5λ0×0.03λ0 at 5GHz, with a cross-sectional height of 0.03λ0.

10. The amplitude-phase independently tunable metasurface array antenna according to claim 1, characterized in that, The amplitude control in the reflective attenuator and the phase control in the reflective phase shifter do not affect each other, and the transmission phase change under different attenuation states when adjusting the amplitude is less than ±5°.

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