Metasurface design methods, devices, equipment, and media based on impedance matching

Abstract

The present invention provides a metasurface design method, apparatus, device, and medium based on impedance matching, including constructing an initial metasurface unit; constructing an equivalent multiport model of the initial metasurface unit; and based on the first and second operating states of the metasurface unit... K The invention involves obtaining the reference impedance of the adjustable device during operation; optimizing the lumped capacitance value of the internal ports to obtain an optimized metasurface unit; acquiring the adjustable device parameters corresponding to a preset phase state and constructing the corresponding metasurface unit; obtaining the array code for the preset beam pointing based on the generalized Snell's law of reflection; and adjusting the operating state of the adjustable devices in each intelligent metasurface unit in the array using the array code to obtain an impedance-matched metasurface. By obtaining the reference impedance of the adjustable device and transforming it into a rigid constraint condition for the optimization model, this invention strictly limits the optimization variables within the feasible region of the adjustable device during design, thereby improving the feasibility of the design.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic metasurface technology, and in particular to a metasurface design method, apparatus, device and medium based on impedance matching. Background Technology

[0002] Metasurfaces are a new type of device based on artificial electromagnetic structures. They can dynamically control the phase, amplitude, and polarization characteristics of electromagnetic waves through subwavelength unit structures, and have important application value in many fields.

[0003] Traditional metasurface design heavily relies on full-wave electromagnetic simulation to iteratively evaluate the geometric parameters of the unit structure. Each parameter adjustment requires resimulation to obtain reflection characteristics, resulting in long design cycles and enormous computational resource consumption. Methods based on multi-port network models utilize mathematical iterations of optimization algorithms but fail to consider the performance limits of tunable devices, limiting their performance analysis and parameter design capabilities. While multi-port network models are introduced, their optimization strategies also have limitations. Directly optimizing the lumped parameters or load impedance values ​​between network ports, using mathematical optimization algorithms to iteratively solve for a set of optimal values, ensures the entire network meets the target reflection coefficient parameters at a specific frequency or band. However, such optimization processes often treat tunable devices as ideal components. The "optimal" lumped parameter values ​​obtained through free iteration in mathematical space may exceed the physical performance limits achievable by actual tunable devices under the current bias state. This leads to mathematically "optimal" results that are physically unattainable, or even if achievable, performance degradation due to device operation in non-ideal conditions. Existing methods lack the ability to incorporate the port impedance characteristics of the adjustable device itself as a core constraint into the optimization framework. Therefore, they cannot ensure that the design results achieve truly optimal performance under the constraints of actual devices. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention provides a metasurface design method, device, equipment and medium based on impedance matching.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] On one hand, this invention provides a metasurface design method based on impedance matching, comprising the following steps:

[0007] An initial metasurface unit is constructed, comprising a metal patch layer, a dielectric layer, and a metal ground layer. The metal patches are connected by internal ports, which include internal active ports and internal passive ports.

[0008] Construct an equivalent multi-port model of the initial metasurface unit;

[0009] The first and second working states based on metasurface unitsK In operation, obtain the reference impedance of the adjustable device, which is equivalent to an internal active port;

[0010] By optimizing the lumped capacitance value of the internal ports, the impedance of the internal passive ports is made to be in impedance matching state with the reference impedance of the adjustable device, thus obtaining an optimized metasurface unit.

[0011] Based on optimized metasurface units, tunable device parameters corresponding to preset phase states are obtained, and corresponding metasurface units are constructed.

[0012] The metasurface units are arranged into an array with a preset size. The array code with a preset beam direction is obtained based on the generalized Snell reflection law. The working state of the adjustable devices in each metasurface unit in the array is adjusted with the array code to obtain an impedance-matched metasurface.

[0013] Furthermore, the reference impedance of the adjustable device is obtained according to the following formula:

[0014] ;

[0015] in, This is the reference impedance for the adjustable device; This represents the real part of the impedance parameter under the first operating condition; This represents the real part of the impedance parameter under the second operating condition; This represents the imaginary part of the impedance parameter under the first operating condition; This represents the imaginary part of the impedance parameter under the second operating condition. It is the imaginary unit.

[0016] Furthermore, the lumped capacitance value of the internal ports is optimized according to the following formula:

[0017] ;

[0018] in, The optimized lumped capacitance value for the internal ports; The value of the lumped capacitance at the internal ports ranges from 1pF to 10pF. This represents the real part of the port impedance parameter given the current lumped capacitance value of the internal ports. This represents the real part of the reference impedance parameter for the adjustable device. This represents the imaginary part of the port impedance parameter under the current internal port lumped capacitance value. This represents the imaginary part of the reference impedance parameter for the adjustable device.

[0019] Furthermore, based on the optimized metasurface unit, tunable device parameters corresponding to a preset phase state are obtained, and the corresponding metasurface unit is constructed, including:

[0020] Maintain the optimized topological parameters of the metasurface unit;

[0021] Obtain the preset phase state;

[0022] The adjustable device parameters corresponding to a preset phase state are obtained using an optimization algorithm, which is based on the following formula:

[0023] ;

[0024] ;

[0025] in, For the first i Each phase state; K Maximum operating state; These are the adjustable device parameters for the first operating state. These are the adjustable device parameters corresponding to the phase state; For metasurface units in The reflection coefficient phase below; For adjustable device parameters;

[0026] The corresponding metasurface unit is constructed based on the adjustable device parameters corresponding to the preset phase state.

[0027] Furthermore, based on the generalized Snell's law of reflection, an array code for a preset beam direction is obtained. This array code is then used to adjust the operating state of the tunable devices in each metasurface unit of the array, including:

[0028] Set the desired angle of the main reflected beam, and calculate the phase difference between two adjacent columns of cells in the metasurface array using the generalized Snell reflection law;

[0029] Array coding is obtained based on the phase difference between two adjacent columns of cells;

[0030] The control parameters of the adjustable devices in each metasurface unit of the array are configured according to the array code.

[0031] Furthermore, the phase difference between two adjacent columns of cells in the metasurface array is calculated according to the following formula:

[0032] ;

[0033] in, The angle at which the main beam is reflected; The wavelength for metasurface operation; This represents the phase difference between two adjacent columns of cells in a metasurface array. is the distance between two adjacent columns of cells in the metasurface array.

[0034] On the other hand, the present invention provides a metasurface design device based on impedance matching, comprising:

[0035] The first module is used to construct the initial metasurface unit, including a metal patch layer, a dielectric layer and a metal ground layer. The metal patches are connected by internal ports, which include internal active ports and internal passive ports.

[0036] The second module is used to construct the equivalent multi-port model of the initial metasurface unit;

[0037] The third module is used for the first and second working states based on metasurface units. K In operation, obtain the reference impedance of the adjustable device, which is equivalent to an internal active port;

[0038] The fourth module is used to optimize the lumped capacitance value of the internal ports so that the impedance of the internal passive ports is in impedance matching state with the reference impedance of the adjustable device, thereby obtaining an optimized metasurface unit.

[0039] The fifth module is used to obtain the adjustable device parameters corresponding to the preset phase state based on the optimized metasurface unit, and to construct the corresponding metasurface unit.

[0040] The sixth module is used to assemble metasurface units into an array with a preset size, obtain the array code of the preset beam direction based on the generalized Snell reflection law, and adjust the working state of the adjustable devices of each metasurface unit in the array with the array code to obtain an impedance-matched metasurface.

[0041] On the other hand, the present invention provides a computer device including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of a metasurface design method based on impedance matching.

[0042] On the other hand, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of a metasurface design method based on impedance matching.

[0043] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0044] The present invention provides a metasurface design method, apparatus, device, and dielectric based on impedance matching. By employing multi-port network modeling technology, the metasurface unit is equivalent to a multi-port network model, thus avoiding the need for full-wave simulation after parameter modification. By obtaining the reference impedance of the tunable device and converting it into a rigid constraint condition for the optimization model, the optimization variables are strictly limited to the feasible region of the tunable device in subsequent design, improving the feasibility of the design. The array code for the preset beam direction is obtained through the generalized Snell's law of reflection. The operating state of the tunable devices in each metasurface unit of the array is adjusted using the array code, enabling the resulting impedance-matched metasurface to obtain the desired electromagnetic wave beam. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0046] Figure 1 A flowchart of a metasurface design method based on impedance matching is provided for one embodiment;

[0047] Figure 2 A schematic diagram of an initial metasurface unit provided in one embodiment;

[0048] Figure 3 A schematic diagram of a multi-port model provided in one embodiment;

[0049] Figure 4 This is a simulation result diagram of a metasurface unit provided in one embodiment. Figure 4 (a) shows the simulation results of the reflection phase of the metasurface unit. Figure 4 (b) is a simulation result of the reflection amplitude of the metasurface unit;

[0050] Figure 5 A schematic diagram of a metasurface array provided in one embodiment;

[0051] Figure 6 The reflection phase curve of a metasurface array provided in one embodiment;

[0052] Figure 7 This is a comparison chart of simulation results and theoretical calculation results for the far-field scattering pattern of a metasurface array provided in one embodiment;

[0053] Figure 8 The far-field pattern of a metasurface array is provided in one embodiment. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] Reference Figure 1 One embodiment provides a metasurface design method based on impedance matching, including the following steps:

[0056] An initial metasurface unit is constructed, comprising a metal patch layer, a dielectric layer, and a metal ground layer. The metal patches are connected by internal ports, which include internal active ports and internal passive ports.

[0057] Construct an equivalent multi-port model of the initial metasurface unit;

[0058] The first and second working states based on metasurface units K In operation, obtain the reference impedance of the adjustable device, which is equivalent to an internal active port;

[0059] By optimizing the lumped capacitance value of the internal ports, the impedance of the internal passive ports is made to be in impedance matching state with the reference impedance of the adjustable device, thus obtaining an optimized metasurface unit.

[0060] Based on optimized metasurface units, tunable device parameters corresponding to preset phase states are obtained, and corresponding metasurface units are constructed.

[0061] The metasurface units are arranged into an array with a preset size. The array code with a preset beam direction is obtained based on the generalized Snell reflection law. The working state of the adjustable devices of each smart metasurface unit in the array is adjusted with the array code to obtain an impedance-matched metasurface.

[0062] The reference impedance of the adjustable device is obtained according to the following formula:

[0063] ;

[0064] in, This is the reference impedance for the adjustable device; This represents the real part of the impedance parameter under the first operating condition; This represents the real part of the impedance parameter under the second operating condition; This represents the imaginary part of the impedance parameter under the first operating condition; This represents the imaginary part of the impedance parameter under the second operating condition. It is the imaginary unit.

[0065] like Figure 2As shown, in one embodiment, an initial metasurface unit is constructed, including a metal patch layer, a dielectric layer, and a metal ground layer. The metal patches are connected by internal ports, which include internal active ports and internal passive ports. Figure 2 The lumped capacitance in the model is equivalent to an internal passive port, the adjustable device is equivalent to an internal active port, and the incident electromagnetic wave is an external port. An equivalent multi-port model of the initial metasurface unit is constructed, such as... Figure 3 As shown, a reflection coefficient model of the metasurface unit is constructed using the impedance parameters of the internal and external ports. The relationship between the voltage and current signals of the external and internal ports is as follows:

[0066] ;

[0067] in, For frequency; This is the equivalent voltage at the external port; This is the equivalent current at the external port; This refers to the voltage at the internal port. For the current of the internal port; This is a matrix representation of the multi-port impedance parameters. for q Self-impedance between external ports for q external ports and N Mutual impedance between internal ports for N Internal ports and q Mutual impedance between external ports for N Mutual impedance between internal ports.

[0068] With angle matrix To describe the reflection coefficient between internal ports:

[0069] ;

[0070] in, For the load of internal passive ports or internal active ports; This is the impedance matrix for the internal ports; M This represents the number of internal ports.

[0071] The relationship between the voltage and current at the internal ports is as follows:

[0072] ;

[0073] The impedance matrix of the external ports is calculated based on the reflection coefficients between the internal ports. :

[0074] ;

[0075] The reflection coefficient of the metasurface unit was further calculated. :

[0076] ;

[0077] in, This is the free-space wave impedance.

[0078] By establishing a model relating the load on the internal ports to the reflection coefficient of the metasurface unit, rapid metasurface parameter analysis and electromagnetic property prediction can be achieved.

[0079] In one embodiment, by optimizing the lumped capacitance value of the internal ports, the impedance of the internal passive ports is made impedance-matched with the reference impedance of the adjustable device, resulting in an optimized metasurface unit. By making the impedance of the internal passive ports impedance-matched with the reference impedance of the adjustable device, the adjustable device operates at its performance limit.

[0080] The lumped capacitance value of the internal ports is optimized according to the following formula:

[0081] ;

[0082] in, The optimized lumped capacitance value for the internal ports; The value of the lumped capacitance at the internal ports ranges from 1pF to 10pF. This represents the real part of the port impedance parameter given the current lumped capacitance value of the internal ports. This represents the real part of the reference impedance parameter for the adjustable device. This represents the imaginary part of the port impedance parameter under the current internal port lumped capacitance value. This represents the imaginary part of the reference impedance parameter for the adjustable device.

[0083] In the optimization process, a heuristic optimization algorithm was employed, including but not limited to genetic algorithms. Optimization was performed using the reference impedance of the adjustable device to ensure the optimized performance was achievable, thus improving the feasibility of the design. The four lumped capacitance values ​​obtained were 1.25pF, 8.86pF, 1pF, and 1.24pF, respectively.

[0084] Based on optimized metasurface units, tunable device parameters corresponding to preset phase states are obtained, and corresponding metasurface units are constructed, including:

[0085] Maintain the optimized topological parameters of the metasurface unit;

[0086] Obtain the preset phase state;

[0087] The adjustable device parameters corresponding to a preset phase state are obtained using an optimization algorithm, which is based on the following formula:

[0088] ;

[0089] ;

[0090] in, For the first i Each phase state; K Maximum operating state; These are the adjustable device parameters for the first operating state. These are the adjustable device parameters corresponding to the phase state; For intelligent metasurface units in The reflection coefficient phase below; For adjustable device parameters;

[0091] The corresponding metasurface unit is constructed based on the adjustable device parameters corresponding to the preset phase state.

[0092] In one embodiment, through multi-port modeling and metasurface unit structure optimization, the eight equivalent capacitances obtained are 2.6pF, 1.65pF, 1.45pF, 1.35pF, 1.28pF, 1.2pF, 1.04pF, and 0.67pF. By adjusting the capacitance parameters of the adjustable device to be equal to the equivalent capacitances, corresponding phase control is achieved. Simulations of the metasurface units corresponding to each equivalent capacitance are shown below. Figure 4 As shown, Figure 4 (a) is a simulation result of the reflection phase of the metasurface unit. It can be seen that the metasurface unit obtained by the present invention can achieve 3-bit phase control. Figure 4 (b) is a simulation result of the reflection amplitude of the metasurface unit. It can be seen that the loss value of the metasurface unit obtained by the present invention is > -4, which meets the design requirements.

[0093] Reference Figure 5 In one embodiment, metasurface units are arranged into a 10×10 array to obtain a metasurface unit array. In each unit of the array, the capacitance value used for phase modulation is the same variable. A probe is added to perform a parameter scanning operation on the capacitance value, obtaining the reflection phase response curve of the constructed metasurface unit array, as shown below. Figure 6 As shown, from Figure 6 As can be seen, the constructed metasurface unit array achieves 3-bit phase control at 3.525 GHz.

[0094] In one embodiment, an array code for a preset beam direction is obtained based on the generalized Snell's law of reflection. The operating state of the tunable devices in each metasurface unit of the array is adjusted using the array code, including:

[0095] Set the desired angle of the main reflected beam, and calculate the phase difference between two adjacent columns of cells in the metasurface array using the generalized Snell reflection law;

[0096] Array coding is obtained based on the phase difference between two adjacent columns of cells;

[0097] The control parameters of the adjustable devices in each metasurface unit of the array are configured according to the array code.

[0098] Through the above processing, the desired electromagnetic wave beam is obtained.

[0099] The phase difference between two adjacent columns of cells in the metasurface array is calculated according to the following formula:

[0100] ;

[0101] in, The angle at which the main beam is reflected; The wavelength for metasurface operation; This represents the phase difference between two adjacent columns of cells in a metasurface array. is the distance between two adjacent columns of cells in the metasurface array.

[0102] The phase and amplitude of the corresponding metasurface are obtained from the array encoding (i.e., array phase encoding), and the far-field scattering pattern of the metasurface can then be calculated using the following formula: ;

[0103] in, This is a far-field scattering pattern of the metasurface. The phase of the reflection coefficient of the metasurface unit; The amplitude of the reflection coefficient of the metasurface unit; The number of rows in the metasurface array. v = 1, ..., V ; U The number of columns in the metasurface array. u = 1, ..., U ; Angle of elevation; It is the azimuth angle; For the far-field mode of the metasurface unit; k The wavenumber in free space; Space for each column; For each line of space.

[0104] In one embodiment, the desired angle of the reflected main beam is set to 25°, and the array code is calculated as "0022446600". The reflection phase and amplitude of the metasurface unit are obtained based on the array code, thereby calculating the far-field scattering pattern corresponding to the metasurface array. The directivity coefficient of the metasurface array is then calculated based on the far-field scattering pattern, specifically according to the following formula:

[0105] ;

[0106] in, denoted as the directionality coefficient of the metasurface array.

[0107] To verify the accuracy of the obtained far-field pattern modeling, far-field scattering patterns encoded as "0022446600" were obtained using electromagnetic simulation and theoretical formulas, respectively, as follows: Figure 7 As shown, the electromagnetic simulation results are basically consistent with the theoretical calculation results in terms of the unknown main lobe and the number of lobes, indicating that the obtained far-field radiation pattern is basically consistent with the actual situation, and the far-field radiation pattern modeling obtained by this method has accuracy.

[0108] In one embodiment, an electromagnetic simulation was performed on a metasurface array with array code "0022446600" at a frequency of 3.525 GHz using a monitor. The results are as follows. Figure 8 As shown in the figure, the simulation results are basically consistent with the theoretical calculations, indicating that the method described in this invention has high accuracy.

[0109] One embodiment provides a metasurface design device based on impedance matching, comprising:

[0110] The first module is used to construct the initial metasurface unit, including a metal patch layer, a dielectric layer and a metal ground layer. The metal patches are connected by internal ports, which include internal active ports and internal passive ports.

[0111] The second module is used to construct the equivalent multi-port model of the initial metasurface unit;

[0112] The third module is used for the first and second working states based on metasurface units. K In operation, obtain the reference impedance of the adjustable device, which is equivalent to an internal active port;

[0113] The fourth module is used to optimize the lumped capacitance value of the internal ports so that the impedance of the internal passive ports is in impedance matching state with the reference impedance of the adjustable device, thereby obtaining an optimized metasurface unit.

[0114] The fifth module is used to obtain the adjustable device parameters corresponding to the preset phase state based on the optimized metasurface unit, and to construct the corresponding metasurface unit.

[0115] The sixth module is used to assemble metasurface units into an array with a preset size, obtain the array code of the preset beam direction based on the generalized Snell reflection law, and adjust the working state of the adjustable devices of each metasurface unit in the array with the array code to obtain an impedance-matched metasurface.

[0116] On the other hand, the present invention provides a computer device including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the impedance-matching-based metasurface design method provided in any of the above embodiments. The computer device may be a server. The computer device includes a processor, a memory, a network interface, and a database connected via a system bus. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the computer device is used to store sample data. The network interface of the computer device is used for communication with external terminals via a network connection.

[0117] On the other hand, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the impedance-matching-based metasurface design method provided in any of the above embodiments.

[0118] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0119] Matters not covered in this invention are common knowledge.

[0120] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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, they should be considered to be within the scope of this specification.

[0121] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

[0122] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A metasurface design method based on impedance matching, characterized in that, The method comprises the following steps: An initial metasurface unit is constructed, which comprises a metal patch layer, a dielectric layer and a metal ground layer, and the metal patches are connected by internal ports, the internal ports comprising internal active ports and internal passive ports; An equivalent multi-port model of the initial metasurface unit is constructed; Based on the first working state and the second working state of the metasurface unit k In the first working state, the reference impedance of the tunable device is obtained, and the tunable device is equivalent to an internal active port. The internal passive port impedance is matched with the reference impedance of the adjustable device by optimizing the internal port lumped capacitance value, and an optimized metasurface unit is obtained; Based on the optimized metasurface unit, adjustable device parameters corresponding to a preset phase state are obtained, and a corresponding metasurface unit is constructed; The metasurface units are arranged in an array with a preset size, and array encoding corresponding to a preset beam pointing direction is obtained based on the generalized Snell reflection law, and the working state of the adjustable device of each metasurface unit in the array is adjusted according to the array encoding, so that an impedance-matched metasurface is obtained.

2. The impedance matching based metasurface design method of claim 1, wherein, The reference impedance of the adjustable device is obtained according to the following formula: wherein is the reference impedance of the tunable device; is the real part of the impedance parameter in the first operating state; is the real part of the impedance parameter in the second operating state; is the imaginary part of the impedance parameter in the first operating state; is the imaginary part of the impedance parameter in the second operating state; is the imaginary unit.

3. The impedance matching based metasurface design method of claim 2, wherein, The internal port lumped capacitance value is optimized according to the following formula: wherein, is the optimized internal port lumped capacitance value; is the internal port lumped capacitance value, ranging between 1 pF - 10 pF; is the port impedance parameter real part at the current internal port lumped capacitance value; is the reference impedance parameter real part of the tunable device; is the port impedance parameter imaginary part at the current internal port lumped capacitance value; is the reference impedance parameter imaginary part of the tunable device.

4. The design method of impedance-matched metasurface according to claim 3, wherein, Based on the optimized metasurface unit, adjustable device parameters corresponding to a preset phase state are obtained, and a corresponding metasurface unit is constructed, comprising: The topological structure parameters of the optimized metasurface unit are maintained; A preset phase state is obtained; An optimization algorithm is used to obtain adjustable device parameters corresponding to a preset phase state, and the optimization algorithm is according to the following formula: wherein, is a first phase state; i is a maximum operating state; K is a first operating state; is an adjustable device parameter at the first operating state; is an adjustable device parameter corresponding to the phase state; is a reflection coefficient phase of the metasurface unit at is a reflection coefficient phase of the metasurface unit at is an adjustable device parameter; A corresponding metasurface unit is constructed based on the adjustable device parameters corresponding to the preset phase state.

5. The impedance matching based metasurface design method of claim 1, wherein, Based on the generalized Snell reflection law, array encoding corresponding to a preset beam pointing direction is obtained, and the working state of the adjustable device of each metasurface unit in the array is adjusted according to the array encoding, comprising: The angle of the desired reflection main beam is set, and the phase difference between adjacent two columns of units in the metasurface array is calculated by the generalized Snell reflection law; The array encoding is obtained based on the phase difference between adjacent two columns of units; The control parameters of the adjustable device of each metasurface unit in the array are configured according to the array encoding.

6. The impedance matching based metasurface design method of claim 5, wherein, The phase difference between adjacent two columns of units in the metasurface array is calculated according to the following formula: wherein, is an angle of the reflected main beam; is a wavelength at which the metasurface operates; is a phase difference between two adjacent columns of cells in the metasurface array; is a distance between two adjacent columns of cells in the metasurface array.

7. An impedance matching based metasurface design apparatus characterized by, Comprising: The first module is used for constructing an initial metasurface unit, which comprises a metal patch layer, a dielectric layer and a metal ground layer, and the metal patches are connected by internal ports, the internal ports comprising internal active ports and internal passive ports; The second module is used for constructing an equivalent multi-port model of the initial metasurface unit; The third module is configured to acquire the reference impedance of the tunable device based on the first working state and the second working state of the metasurface unit. k The third module is configured to acquire the reference impedance of the tunable device based on the first working state and the second working state of the metasurface unit. The fourth module is used for obtaining an optimized metasurface unit by optimizing the internal port lumped capacitance value, so that the impedance of the internal passive port is matched with the reference impedance of the adjustable device; The fifth module is used for obtaining adjustable device parameters corresponding to a preset phase state based on the optimized metasurface unit, and constructing a corresponding metasurface unit; The sixth module is used for arranging the metasurface units in an array with a preset size, obtaining array encoding corresponding to a preset beam pointing direction based on the generalized Snell reflection law, adjusting the working state of the adjustable device of each metasurface unit in the array according to the array encoding, and obtaining an impedance-matched metasurface.

8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that, The processor executes the computer program to implement the steps of the impedance-matched metasurface design method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, A computer program product comprising a computer readable medium having stored thereon the computer program, the computer program comprising instructions which, when executed by a processor, cause the processor to carry out the steps of the method according to any of claims 1 to 6. A computer program product comprising a computer readable medium having stored thereon the computer program, the computer program comprising instructions which, when executed by a processor, cause the processor to carry out the steps of the method according to any of claims

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