High-isolation dual-polarization independent reconfigurable metasurface and electromagnetic wave regulation method

Abstract

The application discloses a high-isolation dual-polarization independent reconfigurable metasurface and an electromagnetic wave regulation and control method, and relates to the technical field of electromagnetic metamaterials and artificial electromagnetic surfaces.The application comprises a metasurface unit array and a programmable control module;each metasurface unit in the metasurface unit array is independently electrically connected with the programmable control module;the programmable control module generates an x-direction bias signal and a y-direction bias signal according to a preset coding pattern;the metasurface unit array generates x-polarized reflected waves and y-polarized reflected waves in response to a single linearly polarized incident wave according to the x-direction bias signal and the y-direction bias signal.The application provides a high-isolation dual-polarization independent reconfigurable metasurface, realizes simultaneous, independent, continuous and high-precision wavefront control of orthogonal dual-polarized electromagnetic waves, and can simultaneously generate vortex beams with different polarizations and different OAM modes.

Description

Technical Field

[0001] This invention relates to the fields of electromagnetic metamaterials and artificial electromagnetic surfaces, and in particular to a high-isolation dual-polarization independent reconfigurable metasurface and an electromagnetic wave modulation method. Background Technology

[0002] A metasurface is a novel type of artificial electromagnetic material composed of subwavelength-scale (typically smaller than the operating wavelength) artificial structural units arranged in a specific manner on a two-dimensional plane. It can precisely control the phase, amplitude, polarization, and other properties of light or electromagnetic waves with extremely high degrees of freedom. Reconfigurable metasurfaces, by introducing active devices such as PIN diodes and varactor diodes, can also dynamically control the wavefront (the surface formed by connecting points with the same vibration phase during the propagation of a light wave) in real time, demonstrating enormous potential in fields such as wireless communication, computational imaging, and adaptive stealth.

[0003] Orbital Angular Momentum (OAM) multiplexing technology can theoretically provide an infinite number of mutually orthogonal channels, thus offering significant advantages in improving communication capacity and spectral efficiency. Currently, generating multimode OAM beams using reconfigurable metasurfaces has become a research hotspot. However, most existing programmable metasurfaces are limited to generating multimode OAM beams in a single polarization state, failing to fully utilize the information processing capabilities offered by dual-polarization channels.

[0004] In the existing technology, there has been research on dual-polarized programmable metasurfaces, but the metasurfaces still have the following main problems: (1) Insufficient isolation: The isolation between dual-polarized control channels is insufficient, which means that the functions under different polarizations cannot be realized simultaneously and independently, but can only work in time-sharing mode; (2) Limited phase modulation capability: Some schemes can only provide 1-bit phase modulation, which results in the generated beam having problems such as large grating lobes and poor directionality; (3) Insufficient control continuity: How to achieve simultaneous, independent and continuous fine control of dual-polarized electromagnetic waves is still a major challenge.

[0005] Therefore, there is an urgent need for a new metasurface structure design scheme that can solve the above problems. Summary of the Invention

[0006] In view of this, the present invention provides a high-isolation dual-polarized independent reconfigurable metasurface and an electromagnetic wave manipulation method. The dual-polarized reconfigurable metasurface enables simultaneous, independent, continuous and high-precision wavefront manipulation of two orthogonally dual-polarized electromagnetic waves, especially for simultaneously generating vortex beams with different polarizations and different OAM modes.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A highly isolated, dual-polarized, independently reconfigurable metasurface includes: a metasurface unit array and a programmable control module; the metasurface unit array includes multiple metasurface units, and each metasurface unit is independently electrically connected to the programmable control module. The programmable control module is used to generate x-direction offset signals and y-direction offset signals according to a preset coding pattern; Metasurface unit arrays are used to generate x-polarized reflected waves and y-polarized reflected waves in response to a single linearly polarized incident wave based on x-direction and y-direction bias signals.

[0008] Optionally, any metasurface unit in the metasurface unit array is a multilayer composite structure, and the metasurface unit includes a metal pattern layer; The metal pattern layer is set on the top layer of the metasurface unit and has a central rotational symmetry structure. It consists of four identical patches distributed around the center in a rotational symmetry manner, namely two patches in the x-direction and two patches in the y-direction. The patches in the x-direction are used to generate x-polarized reflected waves in response to a single linearly polarized incident wave, and the patches in the y-direction are used to generate y-polarized reflected waves in response to a single linearly polarized incident wave.

[0009] Optionally, each patch of the metal pattern layer contains two elongated strip structures bridged by varactor diodes.

[0010] Optionally, the metasurface unit may further include a first active device, a second active device, a first feed network, and a second feed network; The first active device and the first power supply network are electrically connected, and the second active device and the second power supply network are electrically connected. The first active device and the second active device are integrated on the metal pattern layer. The first power supply network and the second power supply network are integrated on the same plane and disposed below the metal pattern layer, and both are independently electrically connected to the programmable control module. The first active device is used to regulate the electromagnetic response of the patch in the x-direction to a single linearly polarized incident wave, and the second active device is used to regulate the electromagnetic response of the patch in the y-direction to a single linearly polarized incident wave; the first feed network is used to provide a feed path for the first active device, and the second feed network is used to provide a feed path for the second active device.

[0011] Optionally, the positive and negative electrodes of the power supply paths provided by the first power supply network and the second power supply network are independent of each other, and the negative electrodes are respectively connected to the ground plane through independent distributed metallized vias.

[0012] Optionally, the metasurface unit array further includes a bias network layer, which is disposed on the bottom layer of the metasurface unit, and the first feed network and the second feed network are integrated on the bias network layer. The bias network layer is provided with multiple bias lines that correspond one-to-one with the metasurface units, and is connected to the corresponding metasurface units through the bias lines; The bias network layer also has an RF choke structure at the connection between each bias line and the corresponding metasurface unit to isolate the RF signal from the DC bias signal.

[0013] Optionally, the programmable control module is a field-programmable gate array, which includes multiple output channels that correspond one-to-one with the metasurface unit.

[0014] Optionally, the field-programmable gate array is used to apply independent bias voltages to the corresponding first and second active devices through the first and second feed networks of the metasurface units, so that multiple metasurface units can simultaneously modulate the phase of the x-polarized reflected wave and the y-polarized reflected wave under the same single linearly polarized incident wave.

[0015] Optionally, the programmable control module is also used to enable the metasurface unit to achieve continuous phase modulation of x-polarized and y-polarized reflected waves within a set frequency band by adjusting the reverse bias voltage of the varactor diode.

[0016] An electromagnetic wave manipulation method based on a high-isolation, dual-polarized, independently reconfigurable metasurface, for electromagnetic wave manipulation according to any one of claims 1-9, comprising: S1 emission steps: A single linearly polarized incident wave is emitted into the metasurface unit array. The single linearly polarized incident wave generates electric field components in the x-direction and y-direction directions of each metasurface unit. S2 control steps: The programmable control module independently controls the bias signal acting on the corresponding metasurface unit through the first active device and the second active device according to the preset coding pattern, and the preset phase distribution in the x direction and the preset phase distribution in the y direction are formed on the aperture surface of the metasurface unit array respectively. S3 Reflection Steps: The electric field component in the x-direction is reflected by the preset phase distribution in the x-direction of the aperture surface of the metasurface unit array to form the x-target beam, and the electric field component in the y-direction is reflected by the preset phase distribution in the y-direction of the aperture surface of the metasurface unit array to form the y-target beam.

[0017] As can be seen from the above technical solution, compared with the prior art, the present invention provides a high-isolation dual-polarization independent reconfigurable metasurface and an electromagnetic wave control method, which has the following beneficial effects: (1) High isolation and independent control: Through the innovative rotational symmetric top-level structure and the independent dual-fed via structure design, the cross-polarization isolation within the metasurface unit and the same polarization isolation between units are greatly improved, and the simultaneous, parallel and decoupled control of dual-polarized electromagnetic waves is realized for the first time. (2) Wideband, wide-range continuous phase modulation: By optimizing the metasurface unit structure and selecting varactor diodes with large capacitance and wide adjustment range, a continuous phase modulation range of more than 320° was achieved in a wideband (e.g., 9.9 GHz to 10.9 GHz), providing a foundation for high-precision wavefront shaping; (3) High precision and digital control: Combined with a specially designed field programmable gate array, pixel-level and digital precision control of each metasurface unit can be achieved, providing a hardware platform for real-time and dynamic generation of complex electromagnetic functions (such as multi-mode OAM multiplexing under different polarizations); (4) Expanded OAM communication capabilities: Based on the metasurface of the present invention, it is possible to generate x-polarized and y-polarized OAM vortex beams carrying different modes directly under a single 45° linear polarization wave irradiation, which greatly improves the channel capacity and spectrum efficiency of the OAM wireless communication system and has broad application prospects in polarization-assisted secure communication, multi-channel information transmission and other fields. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a high-isolation dual-polarization independent reconfigurable metasurface disclosed in this invention; Figure 2 This is a spatial perspective view and performance diagram of any metasurface unit in the metasurface unit array of the present invention. Figure 2 (a) shows the detailed geometry of the high-isolation metasurface unit and the layout of the underlying bias lines. Figure 2 (b) shows the simulation results of the reflection amplitude of the metasurface unit under different capacitance values. Figure 2 (c) represents the simulation results of the reflection phase of the metasurface unit under different capacitance values; Figure 3 This is a schematic diagram illustrating the polarization insensitivity of the reconfigurable metasurface disclosed in an embodiment of the present invention. Figure 3 (a) shows the simulated surface current distribution of the metasurface unit under x-polarized wave incident conditions with capacitance configurations of Cx and Cy, respectively. Figure 3 (b) shows the simulated surface current distribution under y-polarized wave incident; Figure 4 The graphs show the cross-polarization isolation performance and simulation results of the reconfigurable metasurface disclosed in this invention. Figure 4(a) shows a schematic diagram of the simulation model used to analyze cross-polarization isolation. Figure 4 (b) shows the cross-polarization isolation performance curve obtained from the simulation; Figure 5 The simulation results of this invention, which generates x-polarized and y-polarized vortex beams carrying different OAM modes under 45° linearly polarized wave incidence, are shown in the figure. Figure 5 (a) shows the simulated amplitude and phase distribution at 10.5 GHz, with x-polarization carrying odd mode +1 and y-polarization carrying even mode +2. Figure 5 (b) shows the simulated amplitude and phase distribution at 10.5 GHz, with x-polarization carrying odd-mode +3 and y-polarization carrying even-mode +4. Figure 5 (c) shows the simulated amplitude and phase distribution at 10.5 GHz, with x-polarization carrying odd-mode +5 and y-polarization carrying even-mode +6. Figure 5 (d) shows the simulated amplitude and phase distribution of x-polarization carrying odd mode +7 and y-polarization carrying even mode +8 at 10.5 GHz; Figure 6 This is a schematic diagram of the spatial columnar analysis of the OAM purity of the simulation results disclosed in the embodiments of the present invention. Figure 6 (a) represents the mode purity spectrum of the OAM beam generated by the x-polarized reflected wave. Figure 6 (b) represents the mode purity spectrum of the OAM beam generated by the y-polarized reflected wave. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0022] This invention discloses a high-isolation dual-polarization independent reconfigurable metasurface, comprising: a metasurface unit array and a programmable control module; the metasurface unit array includes multiple metasurface units, and each metasurface unit is independently electrically connected to the programmable control module; The programmable control module is used to generate x-direction offset signals and y-direction offset signals according to a preset coding pattern; Metasurface unit arrays are used to generate x-polarized reflected waves and y-polarized reflected waves in response to a single linearly polarized incident wave based on x-direction and y-direction bias signals.

[0023] Furthermore, by loading different preset phase coding patterns that can realize x-polarization and y-polarization of reflected waves onto the metasurface unit array through a programmable control module, the metasurface unit array can simultaneously carry vortex beams with different orbital angular momentum (OAM) modes in the generated x-polarized reflected waves and y-polarized reflected waves after a single linearly polarized incident wave.

[0024] For example, the programmable control module loads preset x-polarization phase distribution codes and y-polarization phase distribution codes, and the metasurface unit array is used to simultaneously generate vortex beams carrying different OAM modes in the x-polarized reflected wave and y-polarized reflected wave under a single 45° linearly polarized wave incident.

[0025] Optional, refer to Figure 1 and Figure 2 (a) Any metasurface unit in the metasurface unit array is a multilayer composite structure, and the metasurface unit includes a metal pattern layer; The metal pattern layer is set on the top layer of the metasurface unit and has a central rotational symmetry structure. It consists of four identical patches distributed around the center in a rotational symmetry manner, namely two patches in the x-direction and two patches in the y-direction. The patches in the x-direction are used to generate x-polarized reflected waves in response to a single linearly polarized incident wave, and the patches in the y-direction are used to generate y-polarized reflected waves in response to a single linearly polarized incident wave.

[0026] Combination Figure 4 (a) Each patch of the metal patterned layer of any metasurface unit in the metasurface unit array contains two elongated strip structures bridged by varactor diodes.

[0027] Furthermore, the metal patterned layer on the top layer of the metasurface unit is a simplification of the 2x2 joint unit structure. This rotationally symmetric structure can effectively suppress the angular correlation scattering effect, thereby reducing the co-polarization coupling between adjacent metasurface units and enhancing the stability of phase modulation.

[0028] Optionally, the metasurface unit further includes a first active device, a second active device, a first power supply network, and a second power supply network; the first active device and the first power supply network are electrically connected, the second active device and the second power supply network are electrically connected, and the first active device and the second active device are integrated on the metal pattern layer; the first power supply network and the second power supply network are integrated on the same plane and disposed below the metal pattern layer, and both are independently electrically connected to the programmable control module.

[0029] The first active device is used to regulate the electromagnetic response of the patch in the x-direction to a single linearly polarized incident wave, and the second active device is used to regulate the electromagnetic response of the patch in the y-direction to a single linearly polarized incident wave; the first feed network is used to provide a feed path for the first active device, and the second feed network is used to provide a feed path for the second active device.

[0030] Specifically, the first active device and the second active device are integrated onto the metal pattern layer via X-direction and Y-direction patches, respectively; the elongated strip structure of the X-direction patch is used to power the first active device, and the elongated strip structure of the Y-direction patch is used to power the second active device.

[0031] Correspondingly, the varactor diodes on each patch, used to connect the elongated strip structure, are part of the corresponding active devices. After the programmable control module provides a bias signal, it acts on the corresponding active devices through the first and second feed networks respectively. Under the influence of the bias signal, the elongated strip structure generates different bias currents, which affect the varactor diodes, causing them to be in different states. Finally, the metasurface unit where the patch is located responds to the single linearly polarized incident wave according to the state of the varactor diode, generating x-polarized and y-polarized reflected waves carrying vortex beams with different OAM modes.

[0032] Optionally, the positive and negative electrodes of the power supply paths provided by the first power supply network and the second power supply network are independent of each other, and the negative electrodes are respectively connected to the ground plane through independent distributed metallized vias.

[0033] Furthermore, the metasurface unit also includes a first metallized via system and a second metallized via system; the first metallized via system is used to provide positive and negative electrode feeding paths for active devices in the x direction; the second metallized via system is used to provide positive and negative electrode feeding paths for active devices in the y direction.

[0034] refer to Figure 4(a) Taking the x-direction patch as an example, due to the structural design of the metasurface unit, the intermediate layer structure outside its metal pattern layer cannot be directly wired to the positive and negative terminals of the programmable logic controller (PLC) control circuit board. Therefore, vias are required to enable dedicated wiring for other layers under the metal pattern layer of the metasurface unit. To facilitate connection with the control circuit board, the first metallized via near the center of any x-direction patch of the metasurface unit provides a connection channel through a fan-shaped microstrip line to the underlying bias line, serving as an independent positive electrode for the x-direction patch. The two second metallized vias located on the outside of the patch are used to directly connect the x-direction patch to the ground plane, serving as independent negative electrodes for the x-direction patch. That is, the metallized via system provides an independent connection channel for the feed network corresponding to the patch to be electrically connected to the PLC, without interference between them.

[0035] The modulation of reflected waves by the patch of the metal pattern layer of the metasurface unit is the response of the positive and negative electrodes of the corresponding patch to the bias signal through metallized vias. The positive electrode, the first active device, and the first feed network of the patch are electrically connected in sequence, and the negative electrode is connected to the ground plane. The positive and negative electrodes are designed to be independent of each other through metallized vias. Then, under the action of the bias signal sent by the programmable control module received by the positive electrode through the connection path, the patch realizes the electromagnetic response to the incident wave. The incident wave generates an x-polarized reflected wave under the reflection of the patch in the x-direction, and the same applies to the patch in the y-direction.

[0036] In a high-isolation dual-polarization independent reconfigurable metasurface disclosed in this invention, the first metallized via system and the second metallized via system are independent of each other and do not share grounding vias. This design aims to avoid the crossing of induced current loops, thereby improving the cross-polarization isolation between the x and y directions within the metasurface unit. In this embodiment, the metasurface unit provides independent connection paths for the positive and negative electrodes of the metal pattern layer patches. This avoids the crossing of induced current loops and allows the patches to respond electromagnetically to incident waves without interference, generating reflected waves that are less affected, have pure and stable waveforms, and have less interference, thus improving the cross-polarization isolation within the metasurface unit.

[0037] Optionally, the programmable control module is a field-programmable gate array, including multiple output channels that correspond one-to-one with the metasurface units. The number of output channels matches the number of the metasurface units and the total number of polarization channels that each metasurface unit needs to control.

[0038] Specifically, because the metasurface unit can independently control and adjust the x-polarization and y-polarization of the reflected wave, a metasurface unit requires two voltages for power supply, instead of just one voltage (grounding is not counted as one in this invention; only the number of positive voltages needed for polarization control is considered). Each two output channels of the programmable gate array correspond to one metasurface unit, providing different independent voltages for the metasurface unit to independently control and adjust the x-polarization and y-polarization of the reflected wave.

[0039] This invention uses a field-programmable gate array (FPGA) as a programmable control module to perform signal modulation on the metasurface unit array. This is because the output voltage range of the FPGA covers the modulation voltage range of the selected varactor diode, and it can achieve fine and independent voltage output modulation of each metasurface unit in the x and y directions.

[0040] Optionally, the field-programmable gate array is used to apply independent bias voltages to the corresponding first and second active devices through the first and second feed networks of the metasurface units, so that multiple metasurface units can simultaneously and independently control the phase of the x-polarized reflected wave and the y-polarized reflected wave under the same single linearly polarized incident wave.

[0041] Optionally, the metasurface unit array further includes a bias network layer, which is disposed on the bottom layer of the metasurface unit, and the first feed network and the second feed network are integrated on the bias network layer. The bias network layer is provided with bias lines that correspond one-to-one with multiple metasurface units, and is connected to the corresponding metasurface units through the bias lines; The bias network layer also has an RF choke structure at the connection between each bias line and the corresponding metasurface unit to isolate the RF signal from the DC bias signal.

[0042] Optionally, the programmable control module is also used to enable the metasurface unit to adjust the reverse bias voltage of the varactor diode through the bias signal of the programmable control module, so as to realize continuous phase modulation of x-polarized reflected waves and y-polarized reflected waves within a set frequency band range; the set frequency band range is 9.9GHz-10.9GHz.

[0043] like Figure 1 As shown, the reconfigurable metasurface disclosed in this embodiment of the invention can be precisely programmed at the unit level using a specially designed FPGA, enabling real-time control of x-polarized and y-polarized reflected waves. By loading different polarization coding patterns, the emitted bias signal, under the action of the metasurface unit array, can cause each metasurface unit to simultaneously generate two orthogonally polarized vortex beams carrying different OAM modes.

[0044] Specifically, in combination Figure 1 The high-isolation dual-polarization independent reconfigurable metasurface disclosed in this invention consists of a top-layer 20×20 metasurface unit array, a middle ground layer and dielectric layer, a bottom-layer pixel-level bias network, and an external FPGA control system.

[0045] The top layer of metasurface unit array is used to respond to electromagnetic waves incident in space; the middle layer of ground and dielectric layer is used to improve the reflection efficiency of electromagnetic waves; the bottom layer of pixel-level bias network provides an independent DC bias signal path for each metasurface unit, and provides an independent bias line connection for each metasurface unit in the 20×20 metasurface unit array; the FPGA control system is used to generate and output control signals.

[0046] Figure 1 The high-isolation dual-polarization independent reconfigurable metasurface shown can receive independent digital codes for x-polarization and y-polarization respectively. By precisely controlling the bias voltage of the varactor diode on each metasurface unit through FPGA, the phase distribution required for x-polarization and y-polarization reflected waves can be realized on the two-dimensional aperture surface, thereby simultaneously generating specific beams of different polarizations (such as OAM vortex beams of different modes).

[0047] Figure 2 middle, Figure 2 (a) shows the detailed geometry of the high-isolation metasurface unit and the layout of the underlying bias lines. Figure 2 (a) shows a metasurface unit employing a multilayer composite structure consisting of three metal layers, two dielectric layers, and one prepreg layer. Its geometric parameters have been optimized, for example, the unit period p = 22 mm. The top metal pattern (i.e., the metal pattern layer) is the core of the design, composed of four identical patches arranged rotationally symmetrically around a center. Each patch contains two elongated strip structures bridged by a varactor diode. This rotationally symmetrical pattern simplifies the traditional 2x2 joint unit structure, effectively suppressing angular correlation scattering effects, thereby reducing the co-polarization coupling between adjacent metasurface units and enhancing the stability of phase modulation.

[0048] The key design feature of the high-isolation dual-polarization independent reconfigurable metasurface disclosed in this invention lies in the design of the feeding network. Specifically, the first and second feeding networks within the metasurface unit are the crucial innovations enabling independent electromagnetic responses to incident waves in the x and y directions. Taking the patch in the x direction as an example, the metallized vias near the center are connected to the underlying bias line via fan-shaped microstrip lines, serving as independent positive electrodes. Two metallized vias located on the outer side of this patch are directly connected to the ground plane, serving as negative electrodes. Importantly, the varactor diode feeding systems in the x and y directions are completely independent and do not share a central ground via. This independent positive electrode introduction and distributed negative electrode grounding design completely avoids the cross-current loops caused by shared grounding loops, thereby significantly improving the cross-polarization isolation between the x and y directions within the metasurface unit.

[0049] Figure 2 (b) and Figure 2 (c) The simulation results of the reflection amplitude and unfolding phase of the metasurface unit under different capacitance values ​​are presented respectively. Figure 2 (a) In the disclosed high-isolation dual-polarization independent reconfigurable metasurface embodiment, a MACOM MAVR-000120-14110P varactor diode is used, with a capacitance adjustment range of 0.14 pF to 1.15 pF. By changing the reverse bias voltage (0-14V) of the varactor diode to adjust its capacitance value, the reflection phase of the metasurface unit in this embodiment can achieve a continuously adjustable range of over 320° within a wide frequency band of 10-11 GHz, meeting the requirements for high-precision phase quantization (e.g., 2-bit and above).

[0050] Under the premise of realizing the design of a high-isolation dual-polarization independent reconfigurable metasurface, the polarization insensitivity of the high-isolation dual-polarization independent reconfigurable metasurface is analyzed to further verify the feasibility of various structural designs such as the dual-metallized via system and the one-to-one correspondence connection of metasurface units in the above embodiments of the present invention.

[0051] like Figure 3 As shown, where, Figure 3 (a) is the simulated surface current distribution of the metasurface unit under different capacitance configurations of Cx and Cy under x-polarized wave incident; Figure 3(b) shows the simulated surface current distribution under y-polarized wave incidence. As illustrated, it is clear that when an x-polarized wave is incident, the electromagnetic energy only excites a strong surface current at the location of the varactor diode in the x-direction, while the current response in the y-direction is extremely weak; conversely, the same applies when a y-polarized wave is incident. This indicates that changing the capacitor configuration in one polarization direction has minimal impact on the electromagnetic response in the other orthogonal polarization direction. Analysis of the polarization insensitivity of the high-isolation dual-polarized independent reconfigurable metasurface fully demonstrates the feasibility of the present invention, proving that its unique design can simultaneously generate x-polarized and y-polarized reflected vortex beams carrying different OAM modes after reflecting a single-polarity incident wave.

[0052] After completing the polarization insensitivity analysis, the cross-polarization isolation performance was simultaneously verified. For example... Figure 4 As shown, where, Figure 4 (a) is a schematic diagram of the simulation model used to analyze cross-polarization isolation. Figure 4 (b) shows the cross-polarization isolation performance curve obtained from the simulation. According to the structure shown in the figure, the simulation results confirm that the present invention has successfully achieved high cross-polarization isolation between the x-polarization and y-polarization channels through the innovative independent feed network design. This is a key prerequisite for realizing simultaneous and independent control of dual-polarization reflected waves.

[0053] This invention also discloses an electromagnetic wave manipulation method based on a high-isolation dual-polarization independently reconfigurable metasurface, used to control electromagnetic waves according to, for example... Figure 1 The above describes a high-isolation, dual-polarized, independently reconfigurable metasurface for electromagnetic wave manipulation, comprising: S1 transmission steps: A single linearly polarized incident wave is transmitted to the metasurface unit array. The single linearly polarized incident wave generates an electric field component in the x-direction and an electric field component in the y-direction in the x-polarization control direction and the y-polarization control direction of each metasurface unit. The single linearly polarized incident wave is a linearly polarized incident wave whose polarization direction is at a non-zero angle with the orthogonal adjustable dimension. The electric field components in the x-direction and y-direction can be modulated independently. S2 control steps: The programmable control module independently controls the bias signal acting on the corresponding metasurface unit through the first active device and the second active device according to the preset coding pattern, and the preset phase distribution in the x direction and the preset phase distribution in the y direction are formed on the aperture surface of the metasurface unit array respectively. S3 Reflection Steps: The electric field component in the x-direction is reflected by the preset phase distribution in the x-direction of the aperture surface of the metasurface unit array to form the x-target beam, and the electric field component in the y-direction is reflected by the preset phase distribution in the y-direction of the aperture surface of the metasurface unit array to form the y-target beam.

[0054] Optionally, the x-target beam and y-target beam are orthogonal x-polarized waves and y-polarized waves, and the first target beam and the second target beam are orbital angular momentum (OAM) vortex beams carrying different topological charges.

[0055] like Figure 5 As shown, based on the above embodiments, the present invention also discloses a simulation process for simultaneously generating dual-polarized multimode OAM vortex beams. Specifically, Figure 5 (a) Figure 5 (b) Figure 5 (c) Figure 5 (d) shows the simulated amplitude and phase distribution of the x-polarized and y-polarized reflected electric fields at 10.5 GHz with different topological charge numbers. As can be seen from the figure, the electric field amplitude distribution of all vortex beams exhibits a central depression and a surrounding ring shape, while the electric field phase distribution shows a spiral variation along the azimuth direction, clearly demonstrating the characteristics of OAM beams carrying different topological charge numbers. Figure 5 (a) The x-polarization carries an odd-numbered mode +1. Figure 5 (b) is +3. Figure 5 (c) is +5. Figure 5 (d) is +7. Figure 5 (a) The y-polarization carries an even-numbered mode +2. Figure 5 (b) is +4. Figure 5 (c) is +6. Figure 5 (d) is +8. This indicates that, based on the excellent polarization independent control capability of the metasurface of this invention, by loading specific x-polarization and y-polarization spiral phase distribution codes onto the metasurface array using an FPGA, OAM vortex beams carrying different modes can be generated simultaneously and independently in the x-polarization reflected wave and the y-polarization reflected wave under a single 45° linearly polarized plane wave illumination.

[0056] The purity of the OAM mode in generating the dual-polarized multimode OAM vortex beam is further analyzed to verify the accuracy of the high-isolation dual-polarized independent reconfigurable metasurface and electromagnetic wave manipulation method of this invention in controlling the reflected wave generated in response to the incident wave. Figure 6 As shown, where, Figure 6 (a) shows the mode purity spectrum of the OAM beam generated by the x-polarized reflected wave. Figure 6 (b) The mode purity spectrum of the OAM beam generated by the y-polarized reflected wave is shown. The purity analysis results show that the generated OAM beam has the highest energy proportion in its designed main mode, while the energy of other parasitic modes is very low, proving that the metasurface of the present invention can generate high-quality, mode-pure OAM vortex beams.

[0057] In summary, this invention successfully designed and implemented a dual-polarization reconfigurable metasurface with high isolation and a wide range of continuously tunable phase. Through a unique rotationally symmetric unit structure and an independent dual-feed network design, the problem of insufficient isolation between channels in dual-polarization control is fundamentally solved, enabling simultaneous, independent, and continuous manipulation of x-polarized and y-polarized electromagnetic waves. Based on this platform, the ability to simultaneously generate dual-polarization, multi-mode OAM vortex beams with a single feed source has been successfully verified, providing an advanced antenna system solution for future polarization-multiplexed wireless communication, high-precision radar imaging, and holographic encryption.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0059] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-isolation, dual-polarization, independently reconfigurable metasurface, characterized in that, include: Metasurface unit array and programmable control module; The metasurface unit array includes multiple metasurface units, and each metasurface unit is independently electrically connected to the programmable control module. The programmable control module is used to generate x-direction offset signals and y-direction offset signals according to a preset coding pattern; Metasurface unit arrays are used to generate x-polarized reflected waves and y-polarized reflected waves in response to a single linearly polarized incident wave based on x-direction and y-direction bias signals.

2. The high-isolation dual-polarization independently reconfigurable metasurface according to claim 1, characterized in that, Each metasurface unit in the metasurface unit array is a multilayer composite structure, and the metasurface unit includes a metal pattern layer; The metal pattern layer is set on the top layer of the metasurface unit and has a central rotational symmetry structure. It consists of four identical patches distributed around the center in a rotational symmetry manner, namely two patches in the x-direction and two patches in the y-direction. The patches in the x-direction are used to generate x-polarized reflected waves in response to a single linearly polarized incident wave, and the patches in the y-direction are used to generate y-polarized reflected waves in response to a single linearly polarized incident wave.

3. The high-isolation dual-polarization independently reconfigurable metasurface according to claim 2, characterized in that, Each patch of the metal pattern layer contains two elongated strip structures bridged by varactor diodes.

4. The high-isolation dual-polarization independently reconfigurable metasurface according to claim 2, characterized in that, The metasurface unit also includes a first active device, a second active device, a first feed network, and a second feed network; The first active device and the first power supply network are electrically connected, and the second active device and the second power supply network are electrically connected. The first active device and the second active device are integrated on the metal pattern layer. The first power supply network and the second power supply network are integrated on the same plane and disposed below the metal pattern layer, and both are independently electrically connected to the programmable control module. The first active device is used to regulate the electromagnetic response of the patch in the x-direction to a single linearly polarized incident wave, and the second active device is used to regulate the electromagnetic response of the patch in the y-direction to a single linearly polarized incident wave; the first feed network is used to provide a feed path for the first active device, and the second feed network is used to provide a feed path for the second active device.

5. The high-isolation dual-polarization independently reconfigurable metasurface according to claim 4, characterized in that, The positive and negative electrodes of the power supply paths provided by the first and second power supply networks are independent of each other, and the negative electrodes are connected to the ground plane through independent distributed metallized vias.

6. The high-isolation dual-polarization independently reconfigurable metasurface according to claim 4, characterized in that, The metasurface unit array also includes a bias network layer, which is disposed on the bottom layer of the metasurface unit, and the first feed network and the second feed network are integrated on the bias network layer. The bias network layer is provided with multiple bias lines that correspond one-to-one with the metasurface units, and is connected to the corresponding metasurface units through the bias lines; The bias network layer also has an RF choke structure at the connection between each bias line and the corresponding metasurface unit to isolate the RF signal from the DC bias signal.

7. The high-isolation dual-polarization independently reconfigurable metasurface according to claim 2, characterized in that, The programmable control module is a field-programmable gate array, which includes multiple output channels that correspond one-to-one with the metasurface unit.

8. The high-isolation dual-polarization independently reconfigurable metasurface according to claim 7, characterized in that, Field-programmable gate arrays are used to apply independent bias voltages to corresponding first and second active devices through the first and second feed networks of metasurface units, so that multiple metasurface units can simultaneously modulate the phase of x-polarized reflected waves and y-polarized reflected waves under the same single linearly polarized incident wave.

9. A high-isolation dual-polarization independently reconfigurable metasurface according to claim 3, characterized in that, The programmable control module is also used to enable the metasurface unit to achieve continuous phase modulation of x-polarized and y-polarized reflected waves within a set frequency band by adjusting the reverse bias voltage of the varactor diode.

10. A method for electromagnetic wave manipulation based on a high-isolation, dual-polarized, independently reconfigurable metasurface, characterized in that, Electromagnetic wave manipulation using a high-isolation dual-polarized independently reconfigurable metasurface according to any one of claims 1-9, comprising: S1 transmission steps: A single linearly polarized incident wave is transmitted to the metasurface unit array. The single linearly polarized incident wave generates an electric field component in the x-direction and an electric field component in the y-direction in the x-polarization control direction and the y-polarization control direction of each metasurface unit. The single linearly polarized incident wave is a linearly polarized incident wave whose polarization direction is at a non-zero angle with the orthogonal adjustable dimension. The electric field components in the x-direction and y-direction can be modulated independently. S2 control steps: The programmable control module independently controls the bias signal acting on the corresponding metasurface unit through the first active device and the second active device according to the preset coding pattern, and the preset phase distribution in the x direction and the preset phase distribution in the y direction are formed on the aperture surface of the metasurface unit array respectively. S3 Reflection Steps: The electric field component in the x-direction is reflected by the preset phase distribution in the x-direction of the aperture surface of the metasurface unit array to form the x-target beam, and the electric field component in the y-direction is reflected by the preset phase distribution in the y-direction of the aperture surface of the metasurface unit array to form the y-target beam.

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