Metasurface unit and metasurface system

Abstract

The invention discloses a metasurface unit and a metasurface system in the field of artificial electromagnetic materials, the metasurface unit comprises an active metasurface unit and a solar cell panel, and the active metasurface unit comprises a bias circuit and an adjustable element. The adjustable element responds to different bias voltages applied through the bias circuit so as to change the electromagnetic response characteristic of the active metasurface unit; the surface of the solar cell panel is covered with a light-transmitting electrode so that energy collection and electromagnetic wave regulation and control can be achieved at the same time. The active metasurface unit and the solar cell panel are arranged in a stacked mode. The surface of the solar cell panel is covered with a light-transmitting electrode, solar energy can be effectively collected, and the light-transmitting electrode can serve as a carrier with an electromagnetic function. The active metasurface unit and the solar cell panel with the surface covered with the light-transmitting electrode are arranged in a stacked mode, space is saved, the integration level of the system is improved, dynamic regulation and control over the electromagnetic environment can be achieved while the energy collection efficiency is guaranteed, and the solar energy collection system is suitable for various scenes.

Description

Technical Field

[0001] The present invention relates to the field of artificial electromagnetic materials, and in particular to a supersurface unit and a supersurface system. Background Art

[0002] With the rapid development of cutting-edge technologies such as artificial intelligence, edge computing, and smart cities, it has become an urgent need to build an information communication network that is interconnected, interactive in real time, and secure and reliable. However, as the communication frequency band continues to increase, the coverage of a single network has gradually narrowed, and the number of network infrastructure such as base stations and APs has increased significantly, resulting in a sharp increase in network deployment costs and energy consumption. In particular, after the adoption of new technologies such as ultra-large-scale antennas and MIMO, the power consumption of base stations has increased significantly, further pushing up the operating costs of the network. This makes it particularly important to find an information communication solution that is both convenient and economical.

[0003] In this context, RIS (Reconfigurable Intelligent Surface) technology has received widespread attention as a promising solution. RIS consists of a two-dimensional array of independently controlled microwave units on a large scale, which can flexibly control the amplitude, phase and polarization direction of the reflected electromagnetic waves, thereby realizing intelligent control of the electromagnetic environment. However, when the RIS system is deployed on a large scale, it still faces challenges such as system integration, energy efficiency optimization, material selection and power supply. Therefore, how to improve the electromagnetic wave reflection capability of the metasurface system while optimizing its power supply solution and reducing the structural complexity has become an urgent problem to be solved by existing technologies. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a metasurface unit and a metasurface system, which not only realize the self-sufficient power supply function, but also ensure the efficient regulation of electromagnetic waves, have a simple structure and are easy to migrate, while improving the efficiency of photovoltaic power generation.

[0005] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0006] In a first aspect, the present invention provides a metasurface unit, comprising:

[0007] An active metasurface unit, the active metasurface unit comprising a bias circuit and an adjustable element, the adjustable element responding to different bias voltages applied through the bias circuit to change the electromagnetic response characteristics of the active metasurface unit;

[0008] A solar cell panel, the surface of which is covered with a light-transmitting electrode to simultaneously achieve energy collection and electromagnetic wave regulation;

[0009] The active metasurface unit and the solar cell panel are stacked.

[0010] Furthermore, the metasurface unit also includes a substrate and a dielectric layer for isolating and protecting the solar cell panel. The active metasurface unit, the substrate, the dielectric layer and the solar cell panel are stacked in sequence, and the substrate and the dielectric layer are both made of light-transmitting materials.

[0011] Furthermore, the active metasurface unit also includes a first convex electrode and a second convex electrode, one end of the first convex electrode and the second convex electrode are connected through the adjustable element, and the other ends of the first convex electrode and the second convex electrode are respectively connected to the bias circuit; different bias voltages applied by the bias circuit form a voltage difference acting between the first convex electrode and the second convex electrode, and the circuit characteristics of the adjustable element are adjusted based on the voltage difference, thereby changing the electromagnetic response characteristics of the active metasurface unit.

[0012] Furthermore, the first convex electrode, the second convex electrode and the light-transmitting electrode are made of any one of transparent conductive materials and light-transmitting metal grids or a combination of the two.

[0013] Furthermore, the bias circuit includes a first bias circuit, a second bias circuit and a fan-shaped bias, the first bias circuit is connected to the first convex electrode, the second bias circuit is connected to the second convex electrode, and the fan-shaped bias is connected at the connection between the second bias circuit and the second convex electrode.

[0014] In the second aspect, the present invention provides a metasurface system, including a photovoltaic circuit, a power conversion device, an FPGA control system and a plurality of the above-mentioned metasurface units, wherein the photovoltaic circuit is connected to the solar panels of the plurality of the metasurface units, and the plurality of the solar panels are connected in series to form a set of battery packs; the battery packs are connected to the power conversion device through the photovoltaic circuit to provide a DC power supply for the FPGA control system; the FPGA control system is connected to the bias circuits in the plurality of the metasurface units to apply a bias voltage to each metasurface unit, thereby dynamically managing and controlling the electromagnetic response characteristics of the metasurface units.

[0015] Furthermore, the power conversion device includes a DC / DC device, an MPPT device, a voltage stabilizing circuit and a power distribution unit; the input end of the DC / DC device is connected to the battery pack, and is used to convert the direct current output of the battery pack into a required voltage level; the input end of the MPPT device is connected to the battery pack, and is used to measure the voltage and current values ​​of the battery pack in real time; the control end of the MPPT device is connected to the DC / DC device, and is used to generate a control signal according to the measured voltage and current values ​​of the battery pack, and dynamically adjust the equivalent resistance of the DC / DC device to match it with the internal resistance of the battery pack to achieve the maximum power output of the battery pack; the output end of the DC / DC device is connected to the voltage stabilizing circuit, and the voltage stabilizing circuit is connected to the power distribution unit, and is used to provide a voltage-stable power supply for the FPGA control system.

[0016] Furthermore, the FPGA control system includes a communication sensing unit and an FPGA control host, wherein the communication sensing unit is used to collect incident beam information and target beam information of the main communication base station; the FPGA control host is connected to the bias circuit of the metasurface unit through a bias circuit extension line, and the first bias circuit in the bias circuit connects the first convex electrodes of the same row of metasurface units in series and is connected to the power ground line of the FPGA control host; the second bias circuit in the bias circuit is respectively connected to the second convex electrode of each metasurface unit, and the second bias circuits of each metasurface unit are not connected to each other, and are finally connected to the FPGA control host to ensure that the FPGA control host independently adjusts the bias voltage of each metasurface unit, and dynamically manages and controls the electromagnetic response characteristics of the metasurface unit according to the beam information provided by the communication sensing unit.

[0017] Furthermore, the metasurface system further includes an energy storage system, the energy storage system includes an energy storage battery and a power monitoring unit, and the power conversion device further includes a charging / discharging unit.

[0018] The input end of the charging unit is connected to the output end of the DC / DC device for receiving the electric energy provided by the DC / DC device; the output end of the charging unit is connected to the energy storage system for transmitting the electric energy to the energy storage system and charging the energy storage battery;

[0019] The input end of the discharge unit is connected to the energy storage system, and is used to output the electric energy of the energy storage battery in the energy storage system to the DC / DC device; the output end of the discharge unit is connected to the input end of the DC / DC device, the output end of the DC / DC device is connected to the voltage stabilizing circuit, and the voltage stabilizing circuit is connected to the power distribution unit, and is used to provide a stable power supply for the FPGA control system;

[0020] In response to the power supply voltage of the power conversion device not meeting the power supply requirement of the FPGA control system, the power conversion device switches to the energy storage battery to provide power for the FPGA control system; the power monitoring unit monitors the power level and working status of the energy storage battery in real time, thereby ensuring that the energy storage battery can provide power for the FPGA control system when needed.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] 1. The metasurface unit provided in the embodiment of the present invention realizes the dual functions of energy collection and electromagnetic wave regulation by combining the active metasurface unit with the solar panel. First, the surface of the solar panel is covered with a transparent electrode, which can not only effectively collect solar energy, but also serve as a carrier of electromagnetic functions. Secondly, the active metasurface unit adjusts its electromagnetic response characteristics through the bias voltage, so as to flexibly control the reflection, transmission or absorption characteristics of the electromagnetic wave. Stacking the two not only saves space and improves the integration of the system, but also can realize dynamic regulation of the electromagnetic environment while ensuring the energy collection efficiency, which is suitable for a variety of scenarios.

[0023] 2. The metasurface unit provided in the embodiment of the present invention provides support for the active metasurface unit and the solar panel through the substrate, ensuring the stability and durability of the entire structure. At the same time, the light-transmitting dielectric layer provides effective isolation and protection for the solar panel, enhances the environmental adaptability of the system, and prevents damage to the battery by external factors. In addition, the transparent conductive material or the light-transmitting metal grid further improves the light transmittance while ensuring the conductivity of the electrode, ensuring the balance between the energy collection efficiency of the solar cell and the electromagnetic wave regulation function of the metasurface.

[0024] 3. The metasurface system provided by the embodiment of the present invention realizes self-power supply through the battery pack formed by the solar panel, does not require an external power supply, has a high degree of self-sufficiency, and is particularly suitable for application in remote environments or environments that are difficult to access the power grid. The solar panel can not only provide a stable power supply for the FPGA control system, but also has the function of an electromagnetic reflection layer, participating in the electromagnetic wave regulation of the metasurface unit. Through the synergistic effect of the photovoltaic line and the power conversion device, the electric energy of the solar cell can be efficiently supplied to the FPGA control system, and the control system flexibly manages and adjusts the working state of the metasurface unit. At the same time, the active metasurface in the metasurface unit has low power consumption, which not only prolongs the working time of the metasurface system, but also further optimizes the energy utilization efficiency, so that the metasurface system can operate stably for a long time, and has good environmental adaptability and energy self-sufficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic structural diagram of a metasurface unit provided in Embodiment 1 of the present invention;

[0026] Figure 2 is a top view of a metasurface unit provided in Embodiment 1 of the present invention;

[0027] Figure 3 is a schematic diagram of the layered structure of a super surface unit provided in the first embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of the reflection amplitude distribution of the 2-bit state of the 1.8 GHz metasurface unit;

[0029] Figure 5 It is a schematic diagram of the reflection phase distribution of a 1.8GHz metasurface unit in the range of incident angle theta from 0 to 70°;

[0030] Figure 6 This is a schematic diagram of the 1.8GHz metasurface unit array distribution of a 3*2 array;

[0031] Figure 7 This is a schematic diagram of the 1.8GHz metasurface unit array distribution of a 9*16 array;

[0032] Figure 8 is a schematic diagram of the architecture of a metasurface system provided in Embodiment 2 of the present invention;

[0033] Fig. 9 This is a schematic diagram of the continuous phase distribution of a 1.8GHz metasurface system with an 18*44 array when the reflection angle theta is 45° and phi is 45°;

[0034] Fig.10 This is a schematic diagram of the 2-bit discrete phase distribution of a 1.8 GHz metasurface system with an 18*44 array when the reflection angle theta is 45° and phi is 45°;

[0035] Fig.11 It is a schematic diagram of the gain of the 1.8GHz metasurface system in the x-axis direction of the 18*44 array when the reflection angle phi is 0°;

[0036] Fig.12 It is a schematic diagram of the gain in the y-axis direction of the 1.8GHz metasurface system of the 18*44 array when the reflection angle phi is 90°;

[0037] Fig.13 This is a schematic diagram of the three-dimensional effect of the beam of a 1.8GHz metasurface system with an 18*44 array when the reflection angle theta is 45° and phi is 45°.

[0038] The meanings of the reference numerals in the figures are as follows:

[0039] 1. First convex electrode; 2. Second convex electrode; 3. Adjustable element; 4. Fan-shaped bias; 5. Second bias circuit; 6. First bias circuit; 7. Substrate; 8. Dielectric layer; 9. Solar cell panel. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0041] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of this disclosure / application, unless otherwise specified, "plurality" means two or more.

[0042] Embodiment 1:

[0043] This embodiment provides a metasurface unit, including an active metasurface unit and a solar cell panel 9, wherein the active metasurface unit and the solar cell panel 9 are stacked.

[0044] The active metasurface unit includes a bias circuit and an adjustable element 3, wherein the adjustable element 3 responds to different bias voltages applied through the bias circuit to change the electromagnetic response characteristics of the active metasurface unit.

[0045] The active metasurface unit integrates an adjustable element 3, such as a diode, a varactor diode, a MEMS (Micro-Electro-Mechanical Systems) device, a liquid crystal, a phase change material or graphene. These adjustable elements 3 can respond to external control signals such as voltage, temperature, and light, and change the electromagnetic response characteristics of the metasurface unit to adapt it to different operating conditions or task requirements. For example, by controlling the phase of each metasurface unit, dynamic beamforming and direction control can be achieved. In one embodiment of the present invention, the adjustable element 3 uses a varactor diode, the varactor diode model is SMV1405, and its equivalent RLC circuit includes a resistance of 0.8Ω, an inductance of 0.7nH and an equivalent capacitor. When a reverse voltage of 10V is applied, the equivalent capacitance value of the diode is 0.95pF.

[0046] In active metasurface designs, bias circuits are used to provide voltages to control the electromagnetic properties of the metasurface's tuning elements. By applying different bias voltages, the device's electrical properties can be adjusted, such as changing the capacitance of a varactor diode. This adjustment can change the electromagnetic response of the metasurface, thereby optimizing signal processing and reflection properties.

[0047] The surface of the solar cell panel 9 is covered with a light-transmitting electrode to achieve energy collection and electromagnetic wave regulation at the same time. By covering the surface of the solar cell panel 9 with a light-transmitting electrode, it is ensured that the surface of the solar cell panel 9 has good conductivity, so that the solar cell panel 9 also acts as an electromagnetic reflection layer.

[0048] The electromagnetic reflection layer is usually made of a highly conductive material, such as a metal film or other conductive material. By adding an electromagnetic reflection layer to the surface of the solar cell panel 9, the loss of electromagnetic waves inside the structure can be effectively avoided, thereby improving the overall efficiency of the metasurface. Using solar cells as electromagnetic reflection layers can simultaneously achieve the dual functions of energy collection and electromagnetic wave reflection regulation.

[0049] As an embodiment of the present invention, the metasurface unit also includes a substrate 7 and a dielectric layer 8 for isolating and protecting the solar cell panel 9. The active metasurface unit, the substrate 7, the dielectric layer 8 and the solar cell panel 9 are stacked in sequence, and the substrate 7 and the dielectric layer 8 are both made of light-transmitting materials.

[0050] The back side of the active metasurface unit in the metasurface unit is constructed on a substrate 7, and the substrate 7 provides support for the active metasurface unit. In one embodiment of the present invention, the substrate 7 can be made of PET (Polyethylene Terephthalate), such as Figure 3 As shown, the thickness h1 of the substrate 7 is 0.15 mm, the relative dielectric constant is 2.9, and the loss tangent is 0.06. PET has good transparency. The high transparency of PET allows most sunlight to penetrate through it and reach the solar panel 9 below, so as not to significantly affect the light absorption efficiency of the solar panel 9; and the PET material is UV-resistant and can maintain long-term performance stability during outdoor use. At the same time, as the substrate 7, PET has good mechanical strength, which can provide additional support for the entire structure and ensure the stability of the component.

[0051] The dielectric layer 8 plays an electrical insulating role, preventing unnecessary electrical contact between the active metasurface unit and the solar panel 9 and providing protection for the solar panel 9. In one embodiment of the present invention, PC (Polycarbonate) material is selected as the dielectric layer 8, such as Figure 3As shown, the thickness h2 of the dielectric plate made of PC material is 2 mm, the relative dielectric constant is 2.9, and the loss tangent value is 0.001. PC, as an insulating material, can isolate the active metasurface unit and the solar panel 9, prevent electrical short circuit or other electrical interference, and ensure the safety and stability of the entire system. Since the active metasurface unit, substrate 7, dielectric layer 8 and solar panel 9 in this embodiment are stacked in sequence, in order to reduce the thickness, thin-film solar cells such as OPV (Organic Photovoltaics) or perovskite solar cells can be used. Thin-film solar cells are usually thinner and more flexible than traditional silicon-based solar cells, and are therefore more susceptible to mechanical damage. Therefore, PC material is introduced as the dielectric layer 8, and the high strength and impact resistance of PC material can provide effective protection for thin-film solar cells to prevent scratches, bending or cracking; on the other hand, PC material has a high transparency close to glass, and the light transmittance is usually between 85% and 90%. The higher light transmittance enables thin-film solar cells to better absorb light energy. Optionally, if a higher light transmittance is sought, such as a light transmittance of more than 90%, ultra-transparent glass can be selected to replace PC material.

[0052] As an embodiment of the present invention, the active metasurface unit also includes a first convex electrode 1 and a second convex electrode 2, one end of the first convex electrode 1 and the second convex electrode 2 are connected through an adjustable element 3, and the other ends of the first convex electrode 1 and the second convex electrode 2 are respectively connected to the bias circuit; different bias voltages are applied through the bias circuit to form a voltage difference between the first convex electrode 1 and the second convex electrode 2, and the circuit characteristics of the adjustable element 3 are adjusted based on the voltage difference, thereby changing the electromagnetic response characteristics of the active metasurface unit.

[0053] like Figure 1 As shown, the first convex electrode 1 and the second convex electrode 2 are symmetrically connected at both ends of the adjustable element 3. The symmetrical design can reduce the stray electromagnetic wave interference caused by asymmetry, ensure that the electromagnetic wave will not produce undesired scattering or polarization effects when passing through the unit, and ensure that the electromagnetic response of the metasurface unit is uniform and stable. The electrode shape is designed to be convex to enhance the electric field concentration effect, especially at both ends of the varactor diode. This design helps to improve the control efficiency of the adjustable element 3, ensuring that a small change in bias voltage / element capacitance can bring about a significant change in the electromagnetic resonance frequency, thereby affecting the control ability of the electromagnetic wave.

[0054] As an embodiment of the present invention, the first convex electrode 1, the second convex electrode 2 and the light-transmitting electrode are made of any one of transparent conductive materials and light-transmitting metal grids or a combination of the two. More specifically, the electrode can be made of TCO material. The transparent electrode will not block sunlight from irradiating the light absorption layer, allowing more light to enter the battery to increase the photoelectric conversion efficiency of the solar cell, and can also effectively conduct current.

[0055] Optionally, the electrode can also adopt a light-transmitting metal grid, and the design of the light-transmitting metal grid is mainly to take into account the electrical conductivity and light transmittance to ensure the efficiency of the solar cell panel 9. The light-transmitting metal grid is composed of a wide and sparse main grid line and a fine and large number of secondary grid lines, and the main grid line and the secondary grid line are vertically arranged to form a grid structure. The main grid line mainly undertakes the task of collecting and transmitting current. The wide main grid line can effectively reduce resistance and reduce voltage drop, thereby improving electrical conductivity; and the main grid line is designed to be sparse to reduce its shielding of incident light, ensuring that more light can enter the light absorption layer of the battery. The fine secondary grid line covers a larger surface area, which helps to collect the photocurrent on the main grid line, and the large number of secondary grid lines can ensure that the current is evenly collected. Although the secondary grid line is relatively fine, its smaller width reduces the shielding of light.

[0056] Optionally, the electrode may also be a composite electrode made of a TCO material and a metal grid. Specifically, the electrode is a composite electrode made of a TCO and a copper wire grid, such as Figure 2 As shown, the TCO square resistance is 6Ω / sq, the thickness is t1 is 300nm, the copper wire width dl is 0.1mm, the copper wire spacing ds is 2mm, the thickness t2 is 0.01mm, the convex electrode parameters l1 are 18mm, l2 is 40mm, d1 is 17mm, d2 is 14mm, and the spacing w between the electrodes is 1mm. The electrode layer can be made by FPC (Flexible Printed Circuit) technology. FPC technology deposits conductive materials (i.e., TCO and copper) on the substrate 7, and then forms the required electrode pattern through an etching process. Screen printing technology can also be used to print conductive materials directly onto the substrate 7 through a screen to form an electrode pattern. Screen printing technology can print a fine metal grid, thereby achieving good conductivity and light transmittance.

[0057] As an embodiment of the present invention, the bias circuit includes a first bias circuit 6, a second bias circuit 5 and a fan-shaped bias 4, the first bias circuit 6 is connected to the first convex electrode 1, the second bias circuit 5 is connected to the second convex electrode 2, and the fan-shaped bias 4 is connected to the connection between the second bias circuit 5 and the second convex electrode 2.

[0058] The first bias circuit 6 and the second bias circuit 5 are used to provide a bias voltage for the varactor diode to control its capacitance. The fan-shaped bias 4 is set to better distribute the current, reduce resistance and electromagnetic interference. The fan-shaped structure can effectively reduce the local current density and avoid local heating or unstable performance caused by excessive current concentration. In addition, the fan-shaped bias 4-wire design acts as a high-frequency bypass capacitor, which helps to improve the distribution of the electromagnetic field and further optimize the control effect of the electromagnetic wave. More specifically, Figure 3 As shown, the first bias circuit 6, the second bias circuit 5 and the fan-shaped bias 4 are made of TCO material and attached to the substrate 7. The bias line width dp is 0.1mm, the spacing dw between adjacent bias lines is 0.3mm, the arc θ of the fan-shaped bias 4 is 90°, the radius R is 2mm, and the thickness t2 of both is 300nm. The first convex electrode 1 is connected to one side of the super surface unit through the first bias circuit 6, and the second convex electrode 2 is connected to the other side of the super surface through the second bias circuit 5 and the fan-shaped bias 4. In this embodiment, the first convex electrode 1 is a negative electrode, and the second convex electrode 2 is a positive electrode.

[0059] Embodiment 2:

[0060] The present embodiment provides a metasurface system, including a photovoltaic circuit, a power conversion device, an FPGA control system and a plurality of metasurface units as described in the first embodiment, wherein the photovoltaic circuit is connected to the solar panels 9 of the plurality of metasurface units, and the plurality of solar panels 9 are connected in series to form a set of battery packs; the battery packs are connected to the power conversion device through the photovoltaic circuit to provide a DC power supply for the FPGA control system; the FPGA control system is connected to the bias circuits in the plurality of metasurface units to apply a bias voltage to each metasurface unit, thereby dynamically managing and controlling the electromagnetic response characteristics of the metasurface units.

[0061] like Figure 8 As shown, the system forms a battery pack by connecting multiple solar panels 9, and these panels are connected in series through photovoltaic lines, so as to transmit the generated electric energy to the power conversion device. The power conversion device converts the DC voltage provided by the battery pack into a stable power supply required by the FPGA control system. The FPGA control system is connected to the bias circuits in multiple metasurface units, and a bias voltage is applied to each metasurface unit, so as to dynamically manage and control the electromagnetic response characteristics of the metasurface unit.

[0062] As an embodiment of the present invention, the power conversion device includes a DC / DC device, an MPPT device, a voltage stabilizing circuit and a distribution unit; the input end of the DC / DC device is connected to the battery pack, and is used to convert the direct current output of the battery pack into a required voltage level; the input end of the MPPT device is connected to the battery pack, and is used to measure the voltage and current values ​​of the battery pack in real time; the control end of the MPPT device is connected to the DC / DC device, and is used to generate a control signal according to the measured voltage and current values ​​of the battery pack, and dynamically adjust the equivalent resistance of the DC / DC device to match it with the internal resistance of the battery pack to achieve the maximum power output of the battery pack; the output end of the DC / DC device is connected to the voltage stabilizing circuit, and the voltage stabilizing circuit is connected to the distribution unit, and is used to provide a voltage-stable power supply for the FPGA control system.

[0063] like Figure 8 As shown, the power conversion device is composed of multiple components, including a DC / DC device, an MPPT device, a voltage stabilizing circuit and a power distribution unit. These components work together to ensure that the metasurface system can stably and efficiently manage the power supply. The DC / DC device (Direct Current to Direct Current Converter) is responsible for converting the DC voltage obtained from the solar panel 9 into different DC voltages suitable for the requirements of the FPGA control system to ensure that the output voltage meets the requirements of the FPGA control system. The MPPT device (Maximum Power Point Tracking) is responsible for maximizing the output power of the battery pack composed of the solar panel. According to the measured voltage and current of the battery pack, a control signal is generated and sent to the DC / DC device to dynamically adjust the operation of the DC / DC device, that is, to adjust the equivalent resistance of the DC / DC device to match the internal resistance of the battery pack composed of the solar panel. Resistance matching allows the solar panel to work at the optimal point under current conditions and output maximum power. The voltage stabilizing circuit is responsible for maintaining the stability of the output voltage. Even if the input voltage fluctuates or the load changes, the voltage stabilizing circuit can effectively suppress these fluctuations to ensure that the output voltage remains within a predetermined range to avoid negative impacts on the FPGA control system. The power distribution unit is responsible for distributing stable power supply voltage to the FPGA control system of the metasurface system, ensuring the effective transmission and distribution of electrical energy and supporting its normal operation.

[0064] As an embodiment of the present invention, the FPGA control system includes two main components:

[0065] Communication sensing unit and FPGA control host. The function of the communication sensing unit is to collect beam information from the main base station and target beam information. Through this information, the FPGA control system can understand the propagation status of electromagnetic waves and the changes in the target beam in real time.

[0066] The FPGA control host is responsible for managing and regulating all the metasurface units of the metasurface system. It is connected to the bias circuit of each metasurface unit through a bias circuit extension line. The first bias circuit in the bias circuit connects the first convex electrodes of the same row of metasurface units in series and connects to the power ground of the FPGA control host. In this embodiment, the first convex electrodes (i.e., negative electrodes) are connected in series and connected to the ground of the FPGA to provide a fixed reference potential for the second convex electrode (i.e., positive electrode), which ensures that the current loop of each metasurface unit is complete and maintains the normal operation of the circuit; and the series operation avoids separate wiring for the negative electrode of each metasurface unit, reducing the complexity of the circuit.

[0067] The second bias circuit in the bias circuit is respectively connected to the second convex electrode of each metasurface unit, and the second bias circuits of each metasurface unit are not connected to each other, and are finally connected to the FPGA control host. By connecting the positive electrode separately to the FPGA control host, the positive electrode of each metasurface unit is independently controlled, and different precise control voltages are applied to produce different electromagnetic effects. Based on the beam information provided by the communication sensing unit, the FPGA control host can independently adjust the voltage of each metasurface unit. This independent adjustment function enables the metasurface system to accurately control the shape and direction of the electromagnetic beam to optimize the electromagnetic wave regulation performance of the system.

[0068] Through such a configuration, the FPGA control system can achieve fine control of the metasurface unit based on real-time perception of the electromagnetic wave environment, thereby improving the flexibility and efficiency of the overall metasurface system in electromagnetic beam adjustment.

[0069] As an embodiment of the present invention, the metasurface system further includes an energy storage system, the energy storage system includes an energy storage battery and a power monitoring unit, and the power conversion device further includes a charging / discharging unit.

[0070] The input end of the charging unit is connected to the output end of the DC / DC device to receive the electric energy provided by the DC / DC device; the output end of the charging unit is connected to the energy storage system to transmit the electric energy to the energy storage system and charge the energy storage battery;

[0071] The input end of the discharge unit is connected to the energy storage system, and is used to output the electric energy of the energy storage battery in the energy storage system to the DC / DC device; the output end of the discharge unit is connected to the input end of the DC / DC device, the output end of the DC / DC device is connected to the voltage stabilizing circuit, and the voltage stabilizing circuit is connected to the power distribution unit, and is used to provide a stable power supply for the FPGA control system;

[0072] In response to the power supply voltage of the power conversion device not meeting the power supply requirement of the FPGA control system, the power conversion device switches to the energy storage battery to provide power for the FPGA control system; the power monitoring unit monitors the power level and working status of the energy storage battery in real time, thereby ensuring that the energy storage battery can provide power for the FPGA control system when needed.

[0073] The energy storage battery is charged through a DC / DC device and a charging unit. When the voltage provided by the power conversion device is insufficient to meet the power supply requirements of the FPGA control system, the metasurface system will automatically switch to the energy storage system to power the FPGA control system to ensure that the FPGA control system can continue to obtain a stable power supply. In addition, the function of the power monitoring unit is to monitor the power of the energy storage battery and its working status in real time, so as to ensure that the energy storage system can provide power in time when needed, and effectively manage the use and maintenance of the battery. This design scheme can improve the reliability and stability of the metasurface system, ensuring that the FPGA control system can still operate normally under power fluctuations or other unstable conditions.

[0074] In this embodiment, the discharge unit monitors the output voltage of the DC / DC device in real time through a voltage monitor. When the voltage monitor detects that the output voltage of the DC / DC device does not meet the power supply requirements of the FPGA control system, the energy storage battery discharges, that is, switches to the energy storage battery to provide power for the FPGA control system. As an embodiment of the present application, the discharge unit can be implemented by the following scheme, which at least includes a voltage sensor, a voltage comparator and a power switching switch. If necessary, a microcontroller can also be configured to increase the reliability and flexibility of the system and ensure that more complex situations can be handled in actual operation. The input end of the voltage sensor is connected to the output end of the DC / DC device to detect the real-time voltage value; the output end of the voltage sensor is connected to the voltage comparator, and the detected real-time voltage value is transmitted to the voltage comparator; the voltage comparator compares the received real-time voltage value with the preset FPGA control system power supply voltage threshold to determine whether the real-time voltage value meets the requirements of the FPGA control system. If the real-time voltage is lower than the preset value, the voltage comparator can directly generate a control signal for power switching. After the power switching switch receives the power switching signal, the power switches the power to the energy storage battery. The energy storage battery provides a stable power supply for the FPGA control system through the discharge unit, the DC / DC device, the voltage stabilizing circuit and the power distribution unit.

[0075] If necessary, a microcontroller is added between the voltage comparator and the power switch. The controller receives the signals from the voltage comparator and decides whether to switch the power supply based on these signals. The introduction of the controller can provide more processing power and flexibility, especially in the face of instantaneous voltage fluctuations or signal noise, to avoid frequent power switching due to misjudgment. At the same time, the controller can filter or de-jitter the signal of the voltage comparator to ensure that the power switching is triggered only when the voltage output by the DC / DC device is continuously lower than the preset threshold. Through the coordination of the controller, the system can perform a series of condition checks before the power switching to ensure the safety and effectiveness of the power switching. This can not only improve the reliability of the entire power management system, but also extend the life of the energy storage battery through appropriate power management strategies.

[0076] In specific applications, taking a 1.8 GHz metasurface system as an example, the metasurface system is composed of a photovoltaic circuit, a power conversion device, an energy storage system, an FPGA control system, and a plurality of metasurface units as shown in Example 1.

[0077] like Figure 2 As shown, the 1.8 GHz metasurface unit used in this embodiment has an active metasurface unit with a width px of 50 mm and a length py of 70 mm. The solar panel 9 has 18 main grid lines and 60 auxiliary grid lines. The main grid lines have a width of 0.1 mm and a thickness of 0.03 mm. The auxiliary grid lines have a width of 0.09 mm and a thickness of 0.03 mm. The thickness of the TCO material is 80 nm. In general, Figure 1 As shown, the active metasurface unit is the same size as the solar panel 9, and only one active metasurface unit is configured on one solar panel 9 to form the metasurface unit. Optionally, if the size of the solar panel 9 is larger, multiple active metasurface units can be configured on one solar panel 9. Figure 6 As shown, when a HJT heterojunction solar cell with a specification of 210 mm × 105 mm is used, 3 × 2 active metasurface units with a specification of 70 mm × 50 mm can be configured on a HJT heterojunction solar cell panel 9.

[0078] by Figure 6 Taking the 1.8GHz metasurface unit shown in the figure as an example, the response characteristics of the metasurface unit under different electromagnetic wave modes are tested. The incident TM (Transverse Magnetic wave) has an electric field along the y-axis. Under 2-bit phase control of TE (S21) and TM (S22), the amplitude and phase of the reflected electromagnetic wave change. For specific amplitude and phase distribution, see Figure 4 and Figure 5The amplitude of the reflected wave polarization converted to TE (S21) field is very small (less than -25dB), which indicates that the reflected wave with TE polarization conversion has a low reflection efficiency relative to the incident wave and can be ignored. That is, most of the energy of the incident TM wave is still reflected back in the form of TM wave without obvious polarization conversion. As shown in the table below, the difference between adjacent reflection phases of the reflected TM wave is about 90°, and the amplitude is greater than 0.8, that is, the reflection efficiency is high.

[0079]

[0080] The amplitude and phase of the reflected electromagnetic wave of TM (S22) vary with the incident angle theta as shown in the following table and Figure 5 As shown in the figure, when the incident angle theta is in the range of 0-70°, the difference between adjacent reflection phases is around 90°, and the amplitudes are all greater than 0.77.

[0081]

[0082] like Figure 7 As shown in FIG. 1 , in a practical embodiment, the system uses 6×22 solar panels and is equipped with a total of 18×44 active metasurface units. These active metasurface units are evenly distributed on the 1.8 GHz metasurface, forming a planar array consisting of 18×44 metasurface units. In this system, Figure 6 As shown, the main grid lines of the solar panel are arranged parallel to the x-axis, while the secondary grid lines are arranged parallel to the y-axis. This design helps to optimize the electromagnetic performance.

[0083] The solar panels of each metasurface unit provide DC power to the power conversion device through the photovoltaic line, and the supply voltage under normal circumstances is about 60V. Under good sunshine conditions, the power conversion device provides stable and reliable power input for the FPGA control system; at night, on cloudy days, when photovoltaic power generation is insufficient, or when the photovoltaic system fails, the energy storage system continues to provide power to the FPGA control system to ensure the continuous operation of the system.

[0084] Taking the sunshine conditions in Jiangsu as an example, the solar panels in the system are deployed at an angle of 30 degrees to the horizontal plane. The maximum light receiving area of ​​the solar panels is , about 2.91 , annual radiation per unit area , the tilt angle gain of the solar panel The photoelectric conversion efficiency of solar cells is 8%. The efficiency of the power conversion device and circuit is 23%. The total average transmittance of the active metasurface unit, substrate and dielectric layer in the metasurface unit is 85%. The average power consumption of FPGA control system is 81%. for , the total average power consumption of all monitoring units in the metasurface system for , the longest failure time that the metasurface system can tolerate for , the operating voltage of the FPGA control system for .

[0085] According to the capacity of the energy storage battery The calculation formula is: in represents the maximum light-receiving area of ​​all solar cells that make up the metasurface unit, is the annual radiation per unit area in the region, is the tilt angle gain of the solar panel, is the photoelectric conversion efficiency of the solar cell, is the power conversion device and line efficiency, is the total transmittance of the active metasurface unit, substrate and dielectric layer in the metasurface unit, is the average power consumption of the FPGA control system, is the total average power consumption of all monitoring units in the metasurface system, is the longest solar cell failure time that the metasurface system can tolerate, is the operating voltage of the FPGA control system. It can be concluded that the metasurface system needs to be configured with at least one energy storage battery.

[0086] When specifically applied to weak coverage scenarios of power wireless private networks, the 1.8GHz metasurface system provided in this embodiment can enhance far-field communication signals. In far-field communication scenarios, the metasurface system is deployed far away from the base station, usually close to the terminal. Due to the long distance, it can be assumed that the base station signal reaching the metasurface is an equiphase surface, which means that the phase of the signal at each point on the metasurface is almost the same. The metasurface system can achieve directional spatial signal enhancement by adjusting the reflection phase of its different metasurface units. For example, adjust the phase of the metasurface unit to enhance the southeast direction. , Pitch angle 45° Direction signal.

[0087] like Fig. 9 The figure shows the phase distribution of an ideal continuous phase metasurface unit. Fig.10The phase distribution of the metasurface unit with 2-bit discrete phase is shown. Although ideal continuous phase control can provide more precise signal control, discrete phase is usually used in practical applications. 2-bit means that each metasurface unit can switch between four phase states. By adjusting the metasurface unit with 2-bit discrete phase distribution, different and The reflected beam gain is achieved under the value of . After fine phase control, such as Fig.11 and Fig.12 As shown, the metasurface system achieved a gain of 28dB in the x and y directions with smaller side lobes, which means higher signal concentration and less interference.

[0088] like Fig.13 As shown in the figure, after adjusting the phase distribution, the metasurface system is in the southeast direction. , Pitch angle 45° This beamforming technology can increase the signal strength by up to 28dB within a specified angle range.

[0089] The 1.8 GHz metasurface system provided in this embodiment can effectively enhance signals in a specific direction through fine phase control, thereby improving communication quality.

[0090] The present invention can also be extended to existing photovoltaic curtain walls and various monitoring photovoltaic panel scenarios. By sticking the active metasurface unit of the metasurface unit on the assembled photovoltaic module with glass or PC shell, it will not affect the normal power generation function of the photovoltaic module, but also give the photovoltaic module metasurface function, thereby realizing the control and regulation of electromagnetic waves.

[0091] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A metasurface unit, characterized in that: include: An active metasurface unit, the active metasurface unit comprising a bias circuit and an adjustable element, the adjustable element responding to different bias voltages applied through the bias circuit to change the electromagnetic response characteristics of the active metasurface unit; A solar cell panel, the surface of which is covered with a light-transmitting electrode to simultaneously achieve energy collection and electromagnetic wave regulation; The active metasurface unit and the solar cell panel are stacked.

2. The metasurface unit according to claim 1, characterized in that: It also includes a substrate and a dielectric layer for isolating and protecting the solar cell panel. The active metasurface unit, the substrate, the dielectric layer and the solar cell panel are stacked in sequence, and the substrate and the dielectric layer are both made of light-transmitting materials.

3. The metasurface unit according to claim 1, characterized in that: The active metasurface unit also includes a first convex electrode and a second convex electrode, one end of the first convex electrode and the second convex electrode are connected through the adjustable element, and the other ends of the first convex electrode and the second convex electrode are respectively connected to the bias circuit; different bias voltages applied by the bias circuit form a voltage difference acting between the first convex electrode and the second convex electrode, and the circuit characteristics of the adjustable element are adjusted based on the voltage difference, thereby changing the electromagnetic response characteristics of the active metasurface unit.

4. The metasurface unit according to claim 3, characterized in that: The first convex electrode, the second convex electrode and the light-transmitting electrode are made of any one of transparent conductive materials and light-transmitting metal grids or a combination of the two.

5. The metasurface unit according to claim 3, characterized in that: The bias circuit includes a first bias circuit, a second bias circuit and a fan-shaped bias, the first bias circuit is connected to the first convex electrode, the second bias circuit is connected to the second convex electrode, and the fan-shaped bias is connected at the connection between the second bias circuit and the second convex electrode.

6. A metasurface system, characterized in that: It comprises a photovoltaic circuit, a power conversion device, an FPGA control system and a plurality of metasurface units as described in any one of claims 1 to 5, wherein the photovoltaic circuit is connected to the solar panels of the plurality of metasurface units, and the plurality of solar panels are connected in series to form a set of battery packs; the battery packs are connected to the power conversion device through the photovoltaic circuit to provide a DC power supply for the FPGA control system; the FPGA control system is connected to the bias circuits in the plurality of metasurface units to apply a bias voltage to each metasurface unit, thereby dynamically managing and controlling the electromagnetic response characteristics of the metasurface units.

7. The metasurface system according to claim 6, characterized in that: The power conversion device includes a DC / DC device, an MPPT device, a voltage stabilizing circuit and a power distribution unit; the input end of the DC / DC device is connected to the battery pack, and is used to convert the direct current output of the battery pack into a required voltage level; the input end of the MPPT device is connected to the battery pack, and is used to measure the voltage and current values ​​of the battery pack in real time; the control end of the MPPT device is connected to the DC / DC device, and is used to generate a control signal according to the measured voltage and current values ​​of the battery pack, and dynamically adjust the equivalent resistance of the DC / DC device to match it with the internal resistance of the battery pack to achieve the maximum power output of the battery pack; the output end of the DC / DC device is connected to the voltage stabilizing circuit, and the voltage stabilizing circuit is connected to the power distribution unit, and is used to provide a voltage-stable power supply for the FPGA control system.

8. The metasurface system according to claim 6, characterized in that: The FPGA control system includes a communication sensing unit and an FPGA control host. The communication sensing unit is used to collect incident beam information and target beam information of the primary communication base station; The FPGA control host is connected to the bias circuit of the metasurface unit through a bias circuit extension line. The first bias circuit in the bias circuit connects the first convex electrodes of the same row of metasurface units in series and is connected to the power ground line of the FPGA control host; the second bias circuit in the bias circuit is respectively connected to the second convex electrode of each metasurface unit, and the second bias circuits of each metasurface unit are not connected to each other, and are finally connected to the FPGA control host to ensure that the FPGA control host independently adjusts the bias voltage of each metasurface unit, and dynamically manages and controls the electromagnetic response characteristics of the metasurface unit according to the beam information provided by the communication sensing unit.

9. The metasurface system according to claim 7, characterized in that: It also includes an energy storage system, which includes an energy storage battery and a power monitoring unit. The power conversion device also includes a charging / discharging unit. The input end of the charging unit is connected to the output end of the DC / DC device for receiving the electric energy provided by the DC / DC device; the output end of the charging unit is connected to the energy storage system for transmitting the electric energy to the energy storage system and charging the energy storage battery; The input end of the discharge unit is connected to the energy storage system, and is used to output the electric energy of the energy storage battery in the energy storage system to the DC / DC device; The output end of the discharge unit is connected to the input end of the DC / DC device, the output end of the DC / DC device is connected to the voltage stabilizing circuit, and the voltage stabilizing circuit is connected to the power distribution unit to provide a stable power supply for the FPGA control system; In response to the power supply voltage of the power conversion device not meeting the power supply requirement of the FPGA control system, the power conversion device switches to the energy storage battery to provide power for the FPGA control system; The power monitoring unit monitors the power level and working status of the energy storage battery in real time, thereby ensuring that the energy storage battery can provide power to the FPGA control system when needed.

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