Metasurface compatible with polarization conversion and amplitude control

Abstract

The invention belongs to the technical field of metasurfaces, and relates to a metasurface compatible with polarization conversion and amplitude control, which comprises a receiving layer, a first dielectric layer, a floor layer, a second dielectric layer and a radiation layer which are sequentially stacked from top to bottom, the receiving layer is connected with the radiation layer; the receiving layer comprises a first patch, a first amplifier and a first control line which are connected in sequence; the radiation layer comprises a second patch, a second amplifier and a second control line which are connected in sequence; changing the state of the first amplifier and / or the second amplifier to realize polarization conversion; and the bias voltage of the first amplifier is adjusted through the first control line and / or the bias voltage of the second amplifier is adjusted through the second control line, so that independent amplitude control is realized. According to the invention, polarization conversion and amplitude control can be realized.

Description

Technical Field

[0001] The present application relates to the technical field of metasurfaces, and particularly to a metasurface compatible with polarization conversion and amplitude control. Background Art

[0002] With the rapid development of high-frequency electromagnetic systems such as communication, radar, and imaging, metasurfaces with reconfigurable capabilities have become an important technical means for realizing intelligent electromagnetic wave regulation.

[0003] In the prior art, reconfigurable metasurfaces achieve flexible control of electromagnetic waves in parameters such as phase, polarization, and amplitude through artificial periodic structures, and have been widely applied in fields such as beamforming, polarization conversion, and electromagnetic stealth.

[0004] However, there are still many limitations in the dynamic reconfigurability, control freedom, structural integration, and engineering adaptability of existing reconfigurable metasurfaces, making it difficult to meet the requirements of future multi-functional and high-performance electromagnetic systems. Specifically: First of all, traditional passive metasurfaces rely on fixed structural parameters or mechanical rotation, sliding, etc. to achieve function switching, with a slow response speed, making it difficult to achieve fast dynamic regulation, and usually only supporting static polarization or phase modulation, lacking the ability to adjust the amplitude of the transmitted wave in real time, and having poor adaptability in complex electromagnetic environments.

[0005] Secondly, some existing active metasurfaces introduce tuning devices such as PIN diodes and varactor diodes to achieve reconfigurable functions, but most of them focus on achieving single-dimensional control, such as choosing one between polarization state switching or amplitude switch modulation, and cannot achieve two-degree-of-freedom and independent regulation of polarization state and transmitted amplitude; moreover, the introduction of such active devices not only increases the complexity of the feeding network, but also significantly increases the insertion loss, resulting in limited overall gain and making it difficult to meet the requirements of efficient transmission in scenarios such as far-field communication and radar imaging.

[0006] In addition, to achieve multi-polarization output capabilities, many designs need to use multi-layer structure stacking or introduce multiple control channels to independently drive the units, resulting in a large system structure, complex processes, difficult-to-unify control logic, and insufficient reliability and integration. Summary of the Invention

[0007] Based on this, it is necessary to provide a metasurface compatible with polarization conversion and amplitude control for the above technical problems, which can achieve polarization conversion and amplitude control.

[0008] A metasurface compatible with polarization conversion and amplitude control includes, from top to bottom in sequence: a receiving layer, a first dielectric layer, a floor layer, a second dielectric layer, and a radiation layer; The receiving layer is connected to the radiation layer; the receiving layer includes, connected in sequence: a first patch, a first amplifier, and a first control line, and the radiation layer includes, connected in sequence: a second patch, a second amplifier, and a second control line; Changing the state of the first amplifier and / or the second amplifier to achieve polarization conversion; adjusting the bias voltage of the first amplifier through the first control line and / or adjusting the bias voltage of the second amplifier through the second control line to achieve independent amplitude control.

[0009] In one embodiment, changing the state of the first amplifier and / or the second amplifier to achieve polarization conversion includes: Both the first amplifier and the second amplifier are in the cut-off state, and the metasurface exhibits an absorption state; The first amplifier is in the on state and the second amplifier is in the cut-off state, and the metasurface exhibits x-polarized transmission; The first amplifier is in the cut-off state and the second amplifier is in the on state, and the metasurface exhibits y-polarized transmission; Both the first amplifier and the second amplifier are in the on state, and the metasurface exhibits circularly polarized transmission.

[0010] In one embodiment, adjusting the bias voltage of the first amplifier through the first control line and / or adjusting the bias voltage of the second amplifier through the second control line to achieve independent amplitude control includes: Increasing the bias voltage of the first amplifier through the first control line and / or increasing the bias voltage of the second amplifier through the second control line to improve the far-field gain of the x-polarized wave / y-polarized wave and achieve independent amplitude control.

[0011] In one embodiment, the receiving layer further includes: a power divider; The input end of the power divider is connected to the first patch, and the output end of the power divider is divided into two paths. One path is directly connected to the second patch, and the other path is connected to the second patch through the first amplifier to achieve equal-power splitting of the signal and ensure power balance between the two paths.

[0012] In one embodiment, the receiving layer further includes: a first coupling structure; Both ends of the first coupling structure are respectively connected to the first patch and the power divider to simultaneously achieve radio frequency signal coupling and DC isolation; The radiation layer further includes: two second coupling structures; One end of a second coupling structure is connected to one side of the second patch, and the other end is directly connected to the first patch; the other end of the other second coupling structure is connected to the other side of the second patch, and the other end is connected to the first patch through the second amplifier. In one embodiment, the receiving layer further includes: two first DC isolation capacitors; The two first DC isolation capacitors are respectively arranged on two paths of the power divider; The radiation layer further includes: two second DC isolation capacitors; The two second DC isolation capacitors are respectively connected to the output ends of a second coupling structure.

[0013] In one embodiment, the receiving layer further includes: a first power supply bypass capacitor; Two ends of the first power supply bypass capacitor are respectively connected to the output end of the first amplifier and the first control line; The radiation layer further includes: a second power supply bypass capacitor; Two ends of the second power supply bypass capacitor are respectively connected to the output end of the second amplifier and the second control line.

[0014] In one embodiment, the receiving layer further includes: a first choke inductor; One end of the first choke inductor is connected to the output end of the first amplifier, and the other end is connected to the first control line; The radiation layer further includes: a second choke inductor; One end of the second choke inductor is connected to the input end of the second amplifier, and the other end is connected to the second control line.

[0015] In one embodiment, the receiving layer further includes: a first resistor; One end of the first resistor is simultaneously connected to the first power supply bypass capacitor and the first choke inductor, and the other end is connected to the first control line; The radiation layer further includes: a second resistor; One end of the second resistor is simultaneously connected to the second power supply bypass capacitor and the second choke inductor, and the other end is connected to the second control line.

[0016] In one embodiment, it further includes: two coaxial-like structures to ensure the shielding and stability of the signal transmission path; Two ends of the coaxial-like structure are respectively connected to the first patch and the second patch, and are isolated from the floor layer.

[0017] The above-mentioned metasurface compatible with polarization conversion and amplitude control is designed with a receiving layer, a first dielectric layer, a ground plane layer, a second dielectric layer, and a radiation layer stacked on top of each other in sequence from top to bottom. The receiving layer is used to receive incident y-polarized electromagnetic waves, the radiation layer is used to radiate the amplified signal into a transmitted wave of the required polarization form to achieve x-polarized, y-polarized, or circularly polarized output. The ground plane layer is used for radio frequency signal shielding and stable reference potential support, and at the same time serves as the grounding end of the amplifier module. A coaxial-like structure is also provided to connect the receiving layer and the radiation layer to achieve radio frequency signal conduction and electromagnetic coupling transmission of the receiving-amplifying-radiating path, and the co-management of radio frequency and direct current signal paths is realized through a structure-embedded layout. Description of the Drawings

[0018] Figure 1 It is a schematic diagram of the overall structure of a metasurface compatible with polarization conversion and amplitude control in an embodiment; Figure 2 It is a top view of a metasurface compatible with polarization conversion and amplitude control in an embodiment; Figure 3 It is a bottom view of a metasurface compatible with polarization conversion and amplitude control in an embodiment; Figure 4 It is a schematic diagram of the ground plane layer of a metasurface compatible with polarization conversion and amplitude control in an embodiment; Figure 5 It is a top view dimension diagram of a metasurface compatible with polarization conversion and amplitude control in a specific embodiment; Figure 6 It is a bottom view dimension diagram of a metasurface compatible with polarization conversion and amplitude control in a specific embodiment; Figure 7 It is a dimension diagram of the ground plane layer of a metasurface compatible with polarization conversion and amplitude control in a specific embodiment; Figure 8 It is a simulation curve diagram of S parameters when a metasurface compatible with polarization conversion and amplitude control works in the 00 state in an embodiment; Figure 9 It is a simulation curve diagram of S parameters when a metasurface compatible with polarization conversion and amplitude control works in the 01 state in an embodiment; Figure 10 It is a simulation curve diagram of S parameters when a metasurface compatible with polarization conversion and amplitude control works in the 10 state in an embodiment; Figure 11 It is a simulation curve diagram of S parameters when a metasurface compatible with polarization conversion and amplitude control works in the 11 state in an embodiment.

[0019] Reference Signs: Receiving layer 1, first patch 11, first coupling structure 12, first DC isolation capacitor 13, first amplifier 14, first power supply bypass capacitor 15, first choke inductor 16, first resistor 17, first control line 18, power divider 19; First dielectric layer 2; Ground layer 3; Second dielectric layer 4; Radiating layer 5, second patch 51, second coupling structure 52, second DC isolation capacitor 53, second amplifier 54, second power supply bypass capacitor 55, second choke inductor 56, second resistor 57, second control line 58. Detailed implementation manners

[0020] In order to make the objectives, technical solutions and advantages of this application clearer, the following further describes this application in detail with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the protection scope of this application.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0022] In addition, the descriptions such as "first" and "second" in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this application, the meaning of "multiple groups" is at least two groups, such as two groups, three groups, etc., unless otherwise specifically defined.

[0023] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, a physical connection or a wireless communication connection; it may be directly connected or indirectly connected through an intermediate medium, and may be the internal connection of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

[0024] In addition, the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present application.

[0025] The present application provides a metasurface that is compatible with polarization conversion and amplitude control. As Figures 1 to 4 shown, in one embodiment, it includes: a receiving layer, a first dielectric layer, a floor layer, a second dielectric layer, a radiation layer, and two coaxial-like structures; wherein, the receiving layer, the first dielectric layer, the floor layer, the second dielectric layer, and the radiation layer are stacked in sequence from top to bottom. The first dielectric layer, the floor layer, and the second dielectric layer are rectangular with equal sizes and their four sides correspond respectively. The receiving layer is connected to the radiation layer. 1. Receiving layer The receiving layer 1 includes: a first patch 11, a first coupling structure 12, a power divider 19, two first DC isolation capacitors 13, a first amplifier 14, a first power supply bypass capacitor 15, a first choke inductor 16, a first resistor 17, and a first control line 18.

[0026] The first patch 11 is a rectangular structure, and one side is connected to the first coupling structure 12.

[0027] One end of the first coupling structure 12 is connected to the first patch 11, and the other end is connected to the power divider 19 to simultaneously achieve RF signal coupling and DC isolation.

[0028] The input end of the power divider 19 is connected to the first coupling structure 12; the output end of the power divider 19 is divided into two paths. One path is connected to the second patch 51 through a first DC isolation capacitor 13, and the other path is connected to the second patch 51 through another first DC isolation capacitor 13 and the first amplifier 14 in sequence; the setting of the power divider can achieve equal-power splitting of the signal and ensure power balance between the two paths.

[0029] There are two first DC isolation capacitors 13; one end of a first DC isolation capacitor 13 is connected to one path of the power divider 19, and the other end is connected to the second patch 51; one end of the other first DC isolation capacitor 13 is connected to the other path of the power divider 19, and the other end is connected to the first amplifier 14.

[0030] The input end of the first amplifier 14 is connected to the other end of the other first DC isolation capacitor 13, that is, to the other path of the power divider 19; the output end of the first amplifier 14 has three output ends. One output end is connected to the first resistor 17 through the first power supply bypass capacitor 15, another output end is connected to the first resistor 17 through the first choke inductor 16, and the other output end is connected to the second patch 51.

[0031] One end of the first power supply bypass capacitor 15 is connected to an output terminal of the first amplifier 14, and the other end is connected to the first resistor 17.

[0032] One end of the first choke inductor 16 is connected to another output terminal of the first amplifier 14, and the other end is connected to the first resistor 17.

[0033] One end of the first resistor 17 is simultaneously connected to the first power supply bypass capacitor 15 and the first choke inductor 16, and the other end is connected to the first control line 18.

[0034] The first control line 18 is connected to the first amplifier 14 to control the DC bias voltage of the first amplifier. A high level turns it on, and a low level turns it off.

[0035] 2. Radiation layer The radiation layer 5 includes: a second patch 51, two second coupling structures 52, two second DC isolation capacitors 53, a second amplifier 54, a second power supply bypass capacitor 55, a second choke inductor 56, a second resistor 57, and a second control line 58.

[0036] The second patch 51 is a rectangular structure. One side is connected to one second coupling structure 52, and the other side is connected to the other second coupling structure 52, and the two sides connected to the second coupling structure are adjacent sides.

[0037] There are two second coupling structures 52. One end of one second coupling structure 52 is connected to one side of the second patch 51, and the other end is connected to one second DC isolation capacitor 53. One end of the other second coupling structure 52 is connected to the other side of the second patch 51, and the other end is connected to the other second DC isolation capacitor 53.

[0038] There are two second DC isolation capacitors 53. One end of one second DC isolation capacitor 53 is connected to the output terminal of one second coupling structure 52, and the other end is connected to the first patch 11, specifically connected to the first patch 11 through another output terminal of the first amplifier 14. One end of the other second DC isolation capacitor 53 is connected to the output terminal of the other second coupling structure 52, and the other end is connected to the second amplifier 54.

[0039] The input terminal of the second amplifier 54 is connected to the other end of the other second DC isolation capacitor 53. The output terminal of the second amplifier 54 has three. One output terminal is connected to the second resistor 57 through the second power supply bypass capacitor 55, another output terminal is connected to the second resistor 57 through the second choke inductor 56, and another output terminal is connected to the first patch 11.

[0040] One end of the second power supply bypass capacitor 55 is connected to an output terminal of the second amplifier 54, and the other end is connected to the second resistor 57.

[0041] One end of the second choke inductor 56 is connected to another output end of the second amplifier 54 and is also connected to the input end of the second amplifier 54, and the other end is connected to the second resistor 57.

[0042] One end of the second resistor 57 is simultaneously connected to the second power supply bypass capacitor 55 and the second choke inductor 56, and the other end is connected to the second control line 58.

[0043] The second control line 58 is connected to the second amplifier 54 to control the DC bias voltage of the second amplifier. When the level is high, it is turned on, and when the level is low, it is turned off.

[0044] 3. The first dielectric layer The first dielectric layer 2 is a supporting component to provide a bearing space for the receiving layer.

[0045] 4. The second dielectric layer The second dielectric layer 4 is a supporting component to provide a bearing space for the radiation layer.

[0046] 5. The floor layer The floor layer 3 is a grounding component.

[0047] 6. The quasi-coaxial structure There are two quasi-coaxial structures. One end of one quasi-coaxial structure is connected to one end of a first DC isolation capacitor, and the other end is connected to another output end of the second amplifier; one end of the other quasi-coaxial structure is connected to another output end of the first amplifier, and the other end is connected to the other end of a second DC isolation capacitor; that is to say, the quasi-coaxial structure includes an inner layer and an outer layer. The two ends of the inner layer of the quasi-coaxial structure are connected to the first patch and the second patch, and the two ends of the outer layer of the quasi-coaxial structure are connected to the first dielectric layer and the second dielectric layer and are isolated from the floor layer; the two quasi-coaxial structures are arranged and connected to the middle microstrip signal line segment through copper posts to form a closed quasi-coaxial transmission channel, which can not only ensure efficient electromagnetic coupling but also ensure good shielding and mechanical stability of the signal transmission path.

[0048] In this embodiment, the states of the first amplifier and / or the second amplifier are changed to achieve polarization conversion; specifically: when both the first amplifier and the second amplifier are in the cut-off state, the metasurface shows an absorption state, the signal path is interrupted, and the energy is absorbed; when the first amplifier is in the on state and the second amplifier is in the cut-off state, the metasurface shows x-polarized transmission; when the first amplifier is in the cut-off state and the second amplifier is in the on state, the metasurface shows y-polarized transmission; when both the first amplifier and the second amplifier are in the on state, the metasurface shows circularly polarized transmission.

[0049] Adjust the bias voltage of the first amplifier through the first control line and / or adjust the bias voltage of the second amplifier through the second control line to achieve independent amplitude control; specifically: increase the bias voltage of the first amplifier through the first control line and / or increase the bias voltage of the second amplifier through the second control line to increase the far-field gain of the x-polarized wave / y-polarized wave and achieve independent amplitude control.

[0050] The above-mentioned reconfigurable polarization and amplitude-controlled metasurface (RPAM) is designed with a receiving layer, a first dielectric layer, a ground plane layer, a second dielectric layer, and a radiation layer stacked in sequence from top to bottom. The receiving layer serves as a receiving antenna unit for receiving incident y-polarized electromagnetic waves. The radiation layer is used to radiate the amplified signal into a transmitted wave of the desired polarization form to achieve x-polarized, y-polarized, or circularly polarized output. The ground plane layer is used for radio frequency signal shielding and stable reference potential support, and at the same time serves as the ground terminal of the amplifier module. A coaxial-like structure is also set up to connect the receiving layer and the radiation layer to achieve radio frequency signal conduction and electromagnetic coupling transmission of the receive-amplify-radiate path, and realize the coordinated management of radio frequency and DC signal paths through an in-structure embedded layout.

[0051] The metasurface of the present application can achieve polarization conversion. Specifically: by cooperating the switch control with the bias circuit, the conduction states of the first amplifier and the second amplifier are respectively controlled to achieve four switchable working modes, so as to complete the free switching between multiple polarization states in real time without changing the physical structure and meet the dynamic requirements for polarization selection in different scenarios.

[0052] The metasurface of the present application can achieve amplitude control. Specifically: in each amplifier channel, by adjusting the DC bias voltage of the amplifier (control range 5–7V), the gain can be precisely regulated to achieve independent adjustment of the signal gains in the two channels; when the bias voltage increases, the amplifier gain increases correspondingly, and the amplitude of the transmitted wave increases accordingly, achieving independent amplitude control.

[0053] In addition, to reduce the insertion loss and improve the overall efficiency of the system, the present application also adopts the following optimization means in the structural design: use a Wilkinson power divider to complete equal-power splitting of the signal to ensure power balance in the two channels; each coupling structure is a T-shaped microstrip line, which realizes radio frequency signal coupling and DC isolation at the same time, omits additional circuit devices, and improves the reliability of the system; the upper and lower layer patches are connected through a coaxial-like structure, effectively ensuring the shielding and stability of the signal transmission path and reducing the volume at the same time.

[0054] In summary, aiming at multiple technical bottlenecks existing in the existing metasurfaces in terms of functional integration, regulation freedom, and engineering adaptability, especially the following technical problems: it is difficult for the existing metasurface structures to achieve dual-degree-of-freedom and independent dynamic regulation of polarization state and amplitude response in a single device, which greatly limits their application potential in multi-functional and intelligent electromagnetic systems; traditional active metasurfaces rely on complex feeding networks or distributed control units, resulting in redundant structures and significantly increased insertion losses, thus leading to limited overall gain and difficulty in meeting the requirements for efficient transmission in scenarios such as far-field communication and radar imaging; the polarization switching and amplitude adjustment functions are mostly achieved by stacking multiple layers of structures or adding multi-channel controls, with large device volumes, low integration levels, and unsatisfactory response speeds and system reliabilities. In this application, the regulation of two dimensions of polarization control and amplitude modulation is integrated in a compact structure to achieve a higher-degree-of-freedom dynamic control of the propagation characteristics of electromagnetic waves. Specifically: by controlling the switching states of two amplifiers, four working states of absorption, x-polarization transmission, y-polarization transmission, and right-handed circular polarization can be achieved under the condition of y-polarization incidence; at the same time, by adjusting the bias voltage, the transmission gains of different polarization channels can be controlled respectively, with a maximum increase of up to 9 dB. This application is an active reconfigurable metasurface with a compact structure, fast response, high control freedom, and high-gain output, which can achieve dynamic, independent, and efficient control of the polarization state and amplitude of electromagnetic waves, has the capabilities of dynamic polarization switching and real-time amplitude regulation, can be regulated in multiple dimensions, and has the advantages of high integration, fast response, high control precision, and low loss, breaking through the limitations of the existing technology and meeting the performance requirements of intelligent electromagnetic regulation components for the new generation of communication and radar systems, especially suitable for the application requirements of flexibly regulating electromagnetic waves in the fields of communication, radar, and intelligent antennas.

[0055] In a specific embodiment, as Figures 5 to 7 shown (the dimensions of W1, W2, W5, W6, L3, d2, and d3 in the figure are defined according to the existing technology), both the receiving layer and the radiation layer are squares with a side length p = 17 mm and are made of copper; the thicknesses of the first dielectric layer and the second dielectric layer are both h1 = 1 mm and are made of F4B dielectric substrates with a dielectric constant of 2.65 and a loss tangent of approximately 0.001; the grounding layer is formed by copper foil lamination with a side length a of 40 mm and a thickness of h2 = 0.035 mm.

[0056] The power divider adopts a Wilkinson power divider structure with an input port impedance of 50 Ω, and the output ends are respectively connected to two radio frequency paths; there is a λ / 4 difference in the lengths of the two output lines, corresponding to a working frequency of 5 GHz, thereby introducing a 90° fixed phase difference to provide conditions for generating right-handed circular polarization (RHCP) waves; the output ends of the power divider are directly connected to the first amplifier path and the second amplifier path respectively to form an x-polarization path and a y-polarization path.

[0057] The coupling structure adopts a T-shaped coupling structure with a line width W4 of 2.64 mm, a length L2 of 0.3 mm, a coupling slot length L1 of 0.2 mm, and a coupling slot width W3 of 9.65 mm. This structure is used for DC isolation between the RF path and the DC control path on the one hand and provides an impedance matching function on the other hand. Simulation verification shows that the T-shaped coupling structure can effectively ensure the signal energy transmission efficiency within the operating frequency band.

[0058] Both the first amplifier and the second amplifier are commercial RF broadband devices Mini-Circuits Gali-2+ with an operating frequency band covering DC–8 GHz and input / output impedances of 50 Ω. The first amplifier and the second amplifier are respectively used to control the x-polarized and y-polarized paths. The amplifier power supply part is configured with 1 μH choke inductors (the first choke inductor 16 and the second choke inductor 56) and 100 nF power supply bypass capacitors (the first power supply bypass capacitor 15 and the second power supply bypass capacitor 55) to filter out power supply ripple noise. A 100 pF DC isolation capacitor (the first DC isolation capacitor 13 and the second DC isolation capacitor 53) is set at the signal end to prevent the bias voltage from entering the RF path.

[0059] Under the condition of y-polarized electromagnetic wave incidence, by respectively controlling the conduction and cutoff of the first amplifier and the second amplifier (cooperating with the switch control and the bias circuit), the following switchable operating states are available to achieve polarization reconfigurability: Encoding 00, both the first amplifier and the second amplifier are in the cutoff state (OFF state), the signal path is interrupted and cannot transmit, the energy is absorbed, and the metasurface exhibits an absorption state; Encoding 01, the first amplifier is in the conduction state (ON state) and the second amplifier is in the cutoff state (OFF state), the signal only passes through the y-polarized path, and the metasurface exhibits y-polarized transmission; Encoding 10, the first amplifier is in the cutoff state (OFF state) and the second amplifier is in the conduction state (ON state), the signal only passes through the x-polarized path, and the metasurface exhibits x-polarized transmission; Encoding 11, both the first amplifier and the second amplifier are in the conduction state (ON state), both channels are conducting, the signals are superimposed through the two paths, and there is a 90° phase difference between the paths, and the metasurface forms a right-handed circular polarization transmission.

[0060] As Figure 8As shown, the S-parameter curve of the metasurface in this example operating in the 00 state is presented. At this time, both the first amplifier and the second amplifier are in the OFF operating state. The transmission coefficients S21 in the x-polarization and y-polarization directions are both lower than -20 dB, indicating that most of the electromagnetic waves are absorbed by the structure; the reflection coefficient S11 < -10 dB, showing that the incident wave is effectively coupled without reflection.

[0061] As Figure 9 shown, the S-parameter curve of the metasurface in this example operating in the 01 state is presented. At this time, the first amplifier is in the ON state and the second amplifier is in the OFF state. The transmission coefficient of the y-polarization transmission state in the y-polarization is significantly enhanced in the range of 4.8 - 5.1 GHz, with a peak reaching 7.27 dB; the x-polarization component is effectively suppressed, below -15 dB, indicating good polarization purity.

[0062] As Figure 10 shown, the S-parameter curve of the metasurface in this example operating in the 10 state is presented. At this time, the first amplifier is in the OFF state and the second amplifier is in the ON state. The transmission coefficient of the x-polarization transmission state in the x-polarization exceeds 0 dB within 4.8 - 5.1 GHz, with a peak of 7.23 dB; the y-polarization transmission is suppressed below -15 dB, featuring good polarization selectivity.

[0063] As Figure 11 shown, the S-parameter curve of the metasurface in this example operating in the 11 state is presented. At this time, both the first amplifier and the second amplifier are in the ON operating state. In the circular polarization transmission state, the x- and y-polarization channels are simultaneously turned on, and the transmission coefficients are both greater than 0 dB; due to a 90° phase difference introduced in the two channels, the synthesized wave has the characteristics of right-handed circular polarization; the measured axial ratio at the 5 GHz frequency point is AR < 3 dB, verifying the effectiveness of the circular polarization output.

[0064] In the experiment, by loading RPAM at the front end of the antenna, in the 01 state (y-polarization transmission), by adjusting the bias voltage, the far-field gain of the y-polarization wave can be increased from 11.3 dB to 18.7 dB; in the 10 state (x-polarization transmission), the gain of the x-polarization wave can be increased from 9.2 dB to 18.0 dB, with an increase of more than 9 dB, significantly superior to traditional passive metasurfaces. This amplitude regulation function is independent of the polarization state switching process and does not interfere with each other, achieving true two-degree-of-freedom regulation (or can also be controlled together). Since the bias can be set separately for the two channels, independent control of the amplitudes of the x / y-polarization transmitted waves can be achieved, and thus two-degree-of-freedom adjustment of the electromagnetic wave propagation characteristics can be realized.

[0065] The above simulation results show that the RPAM structure of the present application integrates a dual-channel radio frequency amplifier module, a Wilkinson power divider, and a DC bias control network. Without changing the physical structure, through an electrical control method (controlling the switching states of the two amplifiers), under the condition of y-polarized incidence, four polarization operating states (absorption, x-polarized transmission, y-polarized transmission, and right-handed circular polarization) can be dynamically switched. At the same time, by adjusting the bias voltage, the transmission gain of different polarization channels can be controlled respectively, with a maximum increase of up to 9 dB. In summary, through the receive-amplify-re-radiate mechanism, the present application realizes the dynamic and independent adjustment of the polarization state and amplitude of the incident electromagnetic wave, has good reconfigurable polarization conversion and independent amplitude control capabilities (such as amplitude amplification capabilities), and has the advantages of high integration, fast response, high control precision, and low loss, and is suitable for the application requirements of flexible regulation of electromagnetic waves in the fields of communication, radar, and intelligent antennas.

[0066] The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0067] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0068] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A metasurface compatible with polarization conversion and amplitude control, characterized in that It includes, stacked successively from top to bottom: a receiving layer, a first dielectric layer, a floor layer, a second dielectric layer, and a radiation layer; The receiving layer is connected to the radiation layer; the receiving layer includes, connected successively: a first patch, a first amplifier, and a first control line, and the radiation layer includes, connected successively: a second patch, a second amplifier, and a second control line; Changing the state of the first amplifier and / or the second amplifier to achieve polarization conversion; adjusting the bias voltage of the first amplifier through the first control line and / or adjusting the bias voltage of the second amplifier through the second control line to achieve independent amplitude control.

2. The metasurface compatible with polarization conversion and amplitude control according to claim 1, characterized in that Changing the state of the first amplifier and / or the second amplifier to achieve polarization conversion includes: Both the first amplifier and the second amplifier are in the cut-off state, and the metasurface exhibits an absorption state; The first amplifier is in the on state and the second amplifier is in the cut-off state, and the metasurface exhibits x-polarized transmission; The first amplifier is in the cut-off state and the second amplifier is in the on state, and the metasurface exhibits y-polarized transmission; Both the first amplifier and the second amplifier are in the on state, and the metasurface exhibits circularly polarized transmission.

3. The metasurface compatible with polarization conversion and amplitude control according to claim 2, characterized in that Adjusting the bias voltage of the first amplifier through the first control line and / or adjusting the bias voltage of the second amplifier through the second control line to achieve independent amplitude control includes: Increasing the bias voltage of the first amplifier through the first control line and / or increasing the bias voltage of the second amplifier through the second control line to increase the far-field gain of the x-polarized wave / y-polarized wave and achieve independent amplitude control.

4. A metasurface compatible with polarization conversion and amplitude control according to any one of claims 1 to 3, characterized in that, The receiving layer further includes: a power splitter; The input end of the power splitter is connected to the first patch, and the output end of the power splitter is divided into two paths. One path is directly connected to the second patch, and the other path is connected to the second patch through the first amplifier to achieve equal-power splitting of the signal and ensure power balance between the two paths.

5. The metasurface compatible with polarization conversion and amplitude control according to claim 4, characterized in that, The receiving layer further includes: a first coupling structure; Both ends of the first coupling structure are respectively connected to the first patch and the power splitter to simultaneously achieve radio frequency signal coupling and DC isolation; The radiation layer further includes: two second coupling structures; One end of a second coupling structure is connected to one side of the second patch, and the other end is directly connected to the first patch; the other end of the other second coupling structure is connected to the other side of the second patch, and the other end is connected to the first patch through the second amplifier.

6. The metasurface compatible with polarization conversion and amplitude control according to claim 5, characterized in that, The receiving layer further includes: two first DC isolation capacitors; The two first DC isolation capacitors are respectively arranged on the two paths of the power splitter; The radiation layer further includes: two second DC isolation capacitors; The two second DC isolation capacitors are respectively connected to the output end of a second coupling structure.

7. A metasurface compatible with polarization conversion and amplitude control according to any one of claims 1 to 3, characterized in that The receiving layer further includes: a first power supply bypass capacitor; Both ends of the first power supply bypass capacitor are respectively connected to the output end of the first amplifier and the first control line; The radiation layer further includes: a second power supply bypass capacitor; Both ends of the second power supply bypass capacitor are respectively connected to the output end of the second amplifier and the second control line.

8. The metasurface compatible with polarization conversion and amplitude control according to claim 7, wherein The receiving layer further includes: a first choke inductor; One end of the first choke inductor is connected to the output end of the first amplifier, and the other end is connected to the first control line; The radiation layer further includes: a second choke inductor; One end of the second choke inductor is connected to the input end of the second amplifier, and the other end is connected to the second control line.

9. The metasurface compatible with polarization conversion and amplitude control according to claim 8, wherein, The receiving layer further includes: a first resistor; One end of the first resistor is connected to both the first power supply bypass capacitor and the first choke inductor, and the other end is connected to the first control line; The radiation layer further includes: a second resistor; One end of the second resistor is connected to both the second power supply bypass capacitor and the second choke inductor, and the other end is connected to the second control line.

10. A metasurface compatible with polarization conversion and amplitude control according to any one of claims 1 to 3, characterized in that, It further includes: Two quasi-coaxial structures to ensure the shielding and stability of the signal transmission path; Both ends of the quasi-coaxial structure are respectively connected to the first patch and the second patch, and are isolated from the floor layer.

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