A smart electromagnetic metasurface controlled by speech recognition

Abstract

The present invention discloses an intelligent electromagnetic metasurface controlled by voice recognition, comprising: a digital programmable metasurface and a voice control system, wherein the voice control system comprises: a voice recognition module, a computer and a digital-to-analog conversion circuit; wherein the voice recognition module obtains a recognition voice instruction, processes the recognition voice instruction to form corresponding serial port data, and then sends the serial port data to the computer, the computer receives and converts the serial port data, converts the serial port data into a format that can be processed by a digital-to-analog conversion circuit, and then sends the serial port data to the digital-to-analog conversion circuit, and the digital-to-analog conversion circuit generates a corresponding voltage sequence to control the digital programmable metasurface; the present invention utilizes voice signals to regulate the functions of the digital programmable metasurface in real time, can effectively realize functions such as wide beam, RCS reduction, vortex wave and beam splitting, and simultaneously realizes non-contact intelligent regulation, and will have broad application prospects in acoustic and electromagnetic fusion communications.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent electromagnetic metasurfaces, and in particular to an intelligent electromagnetic metasurface controlled by voice recognition. Background Art

[0002] In the past decade, metasurfaces have attracted extensive attention due to their powerful ability to control electromagnetic waves. Metasurfaces are two-dimensional artificial structures composed of periodic or non-periodic subwavelength units. Compared with traditional metamaterials, metasurfaces have the advantages of ultra-thinness, low loss, and easy integration. However, for passive metasurfaces, once processed, their functions are immutable, and people are gradually aware of the limitations of passive metasurfaces in practical applications, namely, limited working bandwidth and fixed functions. Recently, research on active metasurfaces has increased. Active metasurfaces can achieve dynamic regulation of electromagnetic wave frequency, amplitude, phase, polarization and other parameters, providing new degrees of freedom for the design of metasurfaces. Among them, adjustable metasurfaces can expand bandwidth and achieve fine-tuning of similar functions; reconfigurable metasurfaces can achieve switching of several completely different functions.

[0003] In order to achieve real-time control and switching of more different functions, Professor Cui Tiejun and others introduced digital coding representation and field programmable logic gate arrays into active metasurface design in 2014, and proposed digital coding and programmable metasurfaces. This method represents metasurfaces from a digital perspective and establishes a connection between metasurfaces and information science. By designing the coding sequences of "0" and "1", programmable metasurfaces with independently adjustable units can realize more advanced and practical functional devices. Recently, people have tried to control digital and programmable metasurfaces by utilizing electrical, optical, temperature and mechanical methods. The rapid development of information technology has promoted the integration of multiple disciplines, and relevant literature has combined vision and motion with the control of metasurfaces. In fact, hearing also has the ability to transmit information.

[0004] In summary, if voice signals can be combined with metasurfaces, it will greatly expand the current technical field and application prospects of metasurfaces. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a voice recognition-controlled intelligent electromagnetic metasurface, so as to connect voice signals and electromagnetic signals together by integrating a voice recognition module into a programmable metasurface.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A voice recognition controlled intelligent electromagnetic metasurface, the intelligent electromagnetic metasurface comprising:

[0008] A digital programmable metasurface (1) is composed of m×n super subunits (11), each of which comprises: p×q active units (111), a positive voltage bias line (112), a negative voltage bias line (113), a positive metal through hole (114), and a negative metal through hole (115), wherein all active units in the same super subunit share the same reverse bias voltage and have the same reflection coefficient;

[0009] A voice control system (2), comprising: a voice recognition module (21), a computer (22) and a digital-to-analog conversion circuit (23);

[0010] The speech recognition module (21) obtains the recognized speech instruction, processes the recognized speech instruction to form corresponding serial port data, and then sends the serial port data to the computer (22). The computer (22) receives and converts the serial port data, converts it into a format that can be processed by the digital-to-analog conversion circuit (23), and then sends it to the digital-to-analog conversion circuit (23). The digital-to-analog conversion circuit (23) generates a corresponding voltage sequence to control the digital programmable metasurface (1).

[0011] Furthermore, the active unit (111) comprises:

[0012] metal ground(1111);

[0013] A dielectric substrate (1112) disposed on the upper surface of the metal ground (1111);

[0014] A first metal patch (1113) and a second metal patch (1114), which are arranged on the upper surface of the dielectric substrate (1112), a recessed portion is provided on one side of the first metal patch (1113), and both wings of the side have a protruding portion, a protruding portion is provided in the middle of one side of the second metal patch (1114), and the protruding portion of the second metal patch (1114) is embedded in the recessed portion of the first metal patch (1113), wherein a gap is provided between the top surface of the protruding portion of the second metal patch (1114) and the bottom surface of the recessed portion of the first metal patch (1113);

[0015] a variable capacitance diode (1115), which is arranged on the gap, and one end of which is arranged on the upper surface of the first metal patch (1113), and the other end of which is arranged on the upper surface of the second metal patch (1114);

[0016] Wherein, a first DC bias line (1116) is arranged on both wings of the first metal patch (1113) away from the second metal patch (1114), and a second DC bias line (1117) is arranged on both wings of the second metal patch (1114) away from the first metal patch (1113).

[0017] Furthermore, the period of the active unit (111) is L=12 mm, the height of the dielectric substrate (1112) is H=3 mm, the thickness of the metal ground (1111) is 0.018 mm, and the variable capacitance diode (1115) has an adjustable capacitance value in the range of 0.14 to 1.1 pF, and a corresponding reverse bias voltage of 10 to 0 V.

[0018] Furthermore, the positive voltage bias line (112) of the super subunit (11) is connected to the first DC bias line (1116) of each active unit (111), and then connected to the positive electrode of the digital-to-analog conversion circuit (23) through the positive metal through hole (114);

[0019] The negative voltage bias line (113) of the super sub-unit (11) is connected to the second DC bias line (1117) of each active unit (111), and then connected to the negative electrode of the digital-to-analog conversion circuit (23) through the negative metal through hole (115);

[0020] The positive and negative voltages of each super subunit (11) are independently controlled by a digital-to-analog conversion circuit (23).

[0021] Furthermore, the dielectric substrate (1112) is made of F4B, which has a dielectric constant of 2.65 and a loss tangent of 0.001.

[0022] Furthermore, the capacitance value of the variable capacitance diode (1115) is adjusted in real time by changing the reverse bias voltage at both ends thereof; as the capacitance value changes, the active unit (111) has a different reflection coefficient;

[0023] Four types of super subunits (11) with reflection phase differences of 90°, 180°, and 270° are represented by four coding states of "00", "01", "10", and "11".

[0024] Furthermore, it is characterized in that the digital programmable metasurface (1) generates different reflection beams according to different voice commands, each voice command corresponds to a function, each function corresponds to a coding sequence of the digital programmable metasurface (1), and each coding sequence corresponds to a voltage sequence;

[0025] The computer (22) stores voltage sequences required for different functions in advance, and the computer (22) selects the voltage sequence according to the serial port data and manipulates the digital-to-analog conversion circuit (23) to control the digital programmable metasurface (1).

[0026] Further, the functions include: wide beam, RCS reduction, vortex wave and two beams.

[0027] Furthermore, the coding sequence is obtained by optimizing through a genetic algorithm.

[0028] The beneficial effects of the present invention are:

[0029] 1. Traditional adjustable metasurfaces can only achieve fine-tuning between similar functions, while reconfigurable metasurfaces can achieve several completely different functions, but the number of functions is limited. The intelligent electromagnetic metasurface controlled by voice recognition proposed in this invention can independently control the reflection phase of each super subunit, and can achieve real-time switching of thousands of different functions, thus realizing programmable control of the metasurface;

[0030] 2. Existing methods of controlling metasurfaces include electrical control, optical control, temperature control, mechanical control, etc. These control methods require a large number of wires, external power supplies, and complex control circuits, and have problems such as complex operation, large size, high cost, and inability to automatically adjust. The intelligent electromagnetic metasurface controlled by voice recognition proposed in the present invention has low cost and simple structure. The metasurface can be controlled in real time through voice commands, and functions can be automatically switched according to ambient sounds without manual operation, thus realizing adaptive intelligent control and remote contactless control;

[0031] 3. The coding sequence of traditional programmable metasurfaces mainly relies on manual design and optimization. Faced with thousands of coding sequences, it is impossible to achieve rapid overall design of coding sequences, which limits the practical application of coded metasurfaces. The intelligent electromagnetic metasurface controlled by speech recognition proposed in the present invention uses genetic algorithms to optimize coding sequences, which can effectively improve the efficiency of optimizing coding sequences, quickly and effectively select the optimal solution, and provide a new method and approach for the optimization design of coded metasurfaces.

[0032] 4. The intelligent electromagnetic metasurface controlled by voice recognition proposed in the present invention can use voice commands to control the microwave phase. It is an electronic bridge connecting sound input and microwave output, and is expected to provide new technical solutions for the future development of advanced acoustic-electric hybrid devices and acoustic-microwave fusion communication systems;

[0033] 5. The intelligent electromagnetic metasurface with voice recognition control proposed in the present invention can realize 2-bit phase control within a wider frequency band, providing conditions for designing more and more complex functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the principle of a voice recognition-controlled intelligent electromagnetic metasurface provided in Example 1;

[0035] Figure 2 This is a schematic diagram of the structure of the active unit and the super sub-unit provided in Example 1, wherein: Figure 2 a is a schematic diagram of the structure of the active unit. Figure 2 b is a schematic diagram of the structure of a super subunit, which contains a total of 4×4 active units;

[0036] Figure 3 The curve diagram of the reflection coefficient obtained by simulating the active unit provided in Example 1 at different capacitance values ​​versus frequency, wherein: Figure 3 a is the curve of reflection amplitude changing with frequency, Figure 3 b is a graph showing the reflection phase changing with frequency;

[0037] Figure 4 This is a flow chart of the intelligent electromagnetic metasurface based on speech recognition control provided in Example 1;

[0038] Figure 5 A physical picture of the intelligent electromagnetic metasurface controlled by voice recognition provided in Example 1;

[0039] Figure 6 Schematic diagram of the coding sequence of the wide beam and the simulated three-dimensional far-field pattern of the wide beam at 6GHz, where: Figure 6 a is a schematic diagram of the coding sequence, Figure 6 b is the simulated three-dimensional far-field pattern;

[0040] Figure 7 Schematic diagram of the coding sequence for RCS reduction and the simulated three-dimensional far-field pattern of RCS reduction at 6GHz, where: Figure 7 a is a schematic diagram of the coding sequence, Figure 7 b is the simulated three-dimensional far-field pattern;

[0041] Figure 8 Schematic diagram of the coding sequence of the first-order vortex wave, the simulated three-dimensional far-field pattern of the first-order vortex wave at 6 GHz, and the electric field component E of the first-order vortex wave at 6 GHz. x Phase distribution diagram in the xy plane, where Figure 8 a is a schematic diagram of the coding sequence, Figure 8 b is the simulated three-dimensional far-field pattern, Figure 8 c is the phase distribution diagram;

[0042] Fig. 9 Schematic diagram of the coding sequence of the second-order vortex wave, the simulated three-dimensional far-field pattern of the second-order vortex wave at 6 GHz, and the electric field component E of the second-order vortex wave at 6 GHzx Phase distribution diagram in the xy plane, where Fig. 9 a is a schematic diagram of the coding sequence, Fig. 9 b is the simulated three-dimensional far-field pattern, Fig. 9 c is the phase distribution diagram;

[0043] Fig.10 Schematic diagram of the coding sequence of the two beams and the simulated three-dimensional far-field pattern of the two beams at 6GHz, where: Fig.10 a is a schematic diagram of the coding sequence, Fig.10 b is the simulated three-dimensional far-field pattern;

[0044] Fig.11 A schematic diagram of a test scenario of a voice recognition-controlled intelligent electromagnetic metasurface in a microwave darkroom provided in an embodiment;

[0045] Fig.12 This is a comparison chart of the two-dimensional simulation and test results of the intelligent electromagnetic metasurface controlled by voice recognition provided in Example 1, wherein: Fig.12 a is the two-dimensional MATLAB theoretical calculation pattern, simulation pattern and test pattern of wide beam at 6GHz;

[0046] Fig.12 b shows the simulation and test results of RCS reduction; Fig.12 c is the two-dimensional simulation and test patterns of the E-plane of the first-order vortex wave at 6 GHz; Fig.12 d is the two-dimensional simulation and test patterns of the H-plane at 6 GHz for the first-order vortex wave;

[0047] Fig.12 e is the two-dimensional simulation pattern and test pattern of the E-plane of the second-order vortex wave at 6 GHz; Fig.12 f is the two-dimensional simulation and test patterns of the H-plane at 6 GHz for the second-order vortex wave; Fig.12 g is the two-dimensional simulation pattern and test pattern of the two-beam at 6 GHz;

[0048] In the attached figure:

[0049] 1-digital programmable metasurface, 11-super subunit, 111-active unit, 112-positive voltage bias line, 113-negative voltage bias line, 114-positive metal through hole, 115-negative metal through hole, 2-voice control system, 21-voice recognition module, 22-computer, 23-digital-to-analog conversion circuit, 1111-metal ground, 1112-dielectric substrate, 1113-first metal patch, 1114-second metal patch, 1115-varicap diode, 1116-first DC bias line, 1117-second DC bias line. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] Example 1

[0052] See also Figure 1-Figure 12 , this embodiment provides an intelligent electromagnetic metasurface controlled by voice recognition, wherein, Figure 1 This is a schematic diagram of the principle of the metasurface, which consists of a digitally programmable metasurface 1 and a voice control system 2.

[0053] In order to realize the digital programmable metasurface 1, the present embodiment integrates a varactor diode 1115 on the metasurface, and the reflection phase of the active unit 111 can be dynamically changed by changing the reverse bias voltage applied to both ends of the varactor diode 1115. The digital programmable metasurface is composed of 6×6 super subunits 11, and all active units 111 in the same super subunit 11 share the same reverse bias voltage, and each super subunit 11 can be independently controlled.

[0054] The voice control system 2 is composed of a voice recognition module 21, a computer 22 and a digital-to-analog conversion circuit 23 (DAC). When a voice command is issued, the voice recognition module 21 recognizes the command and sends the corresponding serial port data to the computer 22. The computer 22 acts as a relay connection between the voice recognition module 21 and the digital-to-analog conversion circuit 23 (DAC). Then the computer 22 converts the received serial port data into the format required by the DAC and sends it to the DAC. The DAC generates a voltage sequence pre-stored in the computer 22 according to the received serial port data. According to the above process, the digital programmable metasurface can be controlled by changing the voice command.

[0055] Specifically, in this embodiment, a 2-bit active unit 111 is designed that can dynamically adjust the reflective state, wherein: Figure 2 a is a schematic diagram of the structure of the active unit 111. The designed active unit 111 is composed of a dielectric substrate 1112 and a two-layer metal structure, a varactor diode 1115 is embedded in the gap between two metal patches (a first metal patch 1113 and a second metal patch 1114) on the upper surface, the middle layer is the dielectric substrate 1112, in this embodiment, specifically an F4B substrate (dielectric constant 2.65, loss tangent 0.001), and the lower surface is covered with a copper plate as a metal ground 1111.

[0056] The upper and lower ends of each metal patch are connected to connect adjacent active units 111 into a row by placing DC bias lines (first DC bias line 1116 and second DC bias line 1117). The capacitance value of the varactor diode 1115 can be dynamically controlled by changing the reverse bias voltage at both ends of the DC bias line, thereby changing the reflection state of the active unit 111.

[0057] Specifically, in this embodiment, the period of the active unit 111 is L=12 mm, the height of the dielectric substrate 1112 is H=3 mm, the thickness of the metal ground 1111 is 0.018 mm, and the other geometric dimensions are a=0.9 mm, b=6.5 mm, c=3.3 mm, d=0.7 mm, e=4.3 mm, f=8.4 mm, g=2.5 mm, i=1 mm, and t=0.2 mm.

[0058] Specifically, in this embodiment, the model of the varactor diode 1115 is "MA46H120" produced by MACOM Technology Solutions, and the adjustable range of its capacitance value is 0.14 to 1.1 pF, and the corresponding reverse bias voltage is 10 to 0 V.

[0059] Specifically, Figure 2 b is a schematic diagram of the structure of the super subunit 11, which includes 4×4 active units 111 in total. The positive voltage bias line 112 and the negative voltage bias line 113 of the super subunit 11 are connected to the first DC bias line 1116 and the second DC bias line 1117 of each active unit 111, and then connected to the positive and negative electrodes of the digital-to-analog conversion circuit 23 through the positive metal through hole 114 and the negative metal through hole 115.

[0060] Specifically, in this embodiment, all active cells 111 in the same super sub-unit 11 share the same reverse bias voltage and have the same reflection coefficient. Four super sub-units 11 with reflection phase differences of 90°, 180°, and 270° can be represented by four coding states of "00", "01", "10", and "11". The positive and negative voltages of each super sub-unit 11 can be independently controlled by the digital-to-analog conversion circuit 23.

[0061] Specifically, in this embodiment, in order to study the reflection characteristics of the designed active unit 111, this embodiment is simulated in CST software. Figure 3 The curve of reflection coefficient variation with frequency obtained by simulating the active unit under different capacitance values, where Figure 3 a is the reflection amplitude, Figure 3b is the reflection phase. As shown in the shaded area of ​​the figure, in the range of 4.74 to 8.48 GHz, the reflection amplitude is greater than -1.5 dB, and the reflection phase varies from 250 to 306.4°. It can be seen that the designed active unit 111 has the significant advantages of broadband, high reflectivity and large phase shift range. Among them, at 6 GHz, the phase difference of the four cases of 1.1 pF, 0.45 pF, 0.32 pF and 0.14 pF is close to 90°, and the corresponding reverse bias voltages are 0 V, 3 V, 4.8 V and 10 V, respectively.

[0062] Specifically, the key to realizing intelligent electromagnetic metasurfaces controlled by voice recognition is to generate different voltage sequences according to different voice commands, so that the digital programmable metasurface presents different coding states and realizes different functions. Figure 4 Flow chart of intelligent electromagnetic metasurface controlled by voice recognition. More specifically, the voice recognition module 21 (in this embodiment, REC-V2 is used) recognizes the voice command and sends the corresponding serial port data to the computer 22. Then, when different people pronounce the same word, their waveforms are almost the same in the time domain, so the voice control system is suitable for all users. The computer 22 serves as a relay connection between the two modules, converts the received serial port data into the required format and sends it to the digital-to-analog conversion circuit 23, which can generate a voltage sequence based on the received serial port data.

[0063] More specifically, in this embodiment, the digital-to-analog conversion circuit 23 is based on a TLC5628 DAC board, each DAC having 8 independent voltage output channels. The DAC can convert serial port data into information including channel numbers and voltage values. Figure 5 Physical image of the smart electromagnetic metasurface controlled for speech recognition.

[0064] Specifically, in this embodiment, four different functions are designed to demonstrate the performance of the intelligent electromagnetic metasurface controlled by voice recognition, namely: wide beam, RCS reduction, vortex wave and two beams. In the metasurface design stage, the rational use of optimization algorithms can greatly reduce the design time and effectively improve efficiency.

[0065] More specifically, in this embodiment, in order to facilitate the design of the coding sequence of the digital programmable metasurface, this embodiment introduces a genetic algorithm to assist in finding the optimal coding sequence.

[0066] The first function is wide beam. This embodiment uses genetic algorithm to optimize a coding sequence with a beam width of 60° in the x direction, such as Figure 6 As shown in a, Figure 6 a is the three-dimensional far-field pattern of the wide beam simulated at 6 GHz.

[0067] The second function is RCS reduction. By optimizing the coding sequence, the metasurface is able to randomly disperse the incident waves into various directions. Figure 7 a is the optimized RCS-reduced coding sequence, Figure 7 b is the three-dimensional far-field radiation pattern obtained by simulating RCS reduction at 6 GHz. It can be seen that the reflected main beam is missing and the energy diverged in each direction is relatively small.

[0068] The third function is vortex wave. Figure 8 a. Figure 8 b and Fig. 9 a. Fig. 9 As shown in Figure 2b, it can be seen that there is a hollow ring in the middle of each three-dimensional beam, and the ring of the second-order vortex wave is slightly larger than that of the first-order vortex wave, which is consistent with the characteristics of the vortex wave. The near-field phase distribution is also an important feature to describe the performance of the vortex wave. Figure 8 c. Fig. 9 c are the electric field components E of the first-order vortex wave and the second-order vortex wave at 6 GHz. x In the phase distribution diagram of the xy plane, one-turn and two-turn spiral phase distributions can be clearly seen.

[0069] The fourth function is two beams. Fig.10 a is the coding sequence of the two beams, Fig.10 b is the three-dimensional far-field radiation pattern of the two beams simulated at 6 GHz. It can be seen that there are two symmetrical main beams in the upper half space.

[0070] Specifically, in order to experimentally verify the performance of the intelligent electromagnetic metasurface controlled by speech recognition, this embodiment was tested in a microwave darkroom.

[0071] Fig.11 Testing scenario of smart electromagnetic metasurface controlled for speech recognition in a microwave darkroom. Fig.12 Comparison of two-dimensional simulation and test results of intelligent electromagnetic metasurface for speech recognition control. Fig.12 a is the two-dimensional MATLAB theoretical calculation pattern, simulation pattern and test pattern of wide beam at 6GHz. The 5dB beam width calculated theoretically in Matlab is -29°~29°, the 5dB beam width obtained by simulation is also -28°~28°, and the 5dB beam width obtained by experiment is -26°~26°, and the three are in good agreement. Fig.12b is the simulation and test results of RCS reduction. In order to accurately represent the value of energy dissipation, we also tested the RCS of a reference metal plane of the same size as the proposed digital programmable metasurface, and calculated the RCS reduction of a single station by subtracting the RCS of the reference metal plane from the RCS of the digital programmable metasurface. The RCS reduction range of -7dB is from 5.1 to 8.2GHz, and the maximum RCS reduction is -15.88dB at 6.5GHz. Fig.12 c. Fig.12 d is the two-dimensional simulation and test patterns of the E and H planes of the first-order vortex wave at 6 GHz. Fig.12 e. Fig.12 f is the two-dimensional simulation and test patterns of the E and H planes of the second-order vortex wave at 6 GHz. It can be seen that a trough appears in the middle of the pattern, with two peaks on both sides of the trough, which is basically consistent with the pattern obtained by simulation. Fig.12 g is the two-dimensional simulation radiation pattern and test radiation pattern of the two beams at 6 GHz. The two reflected main beams point to -32° and 31° respectively, which is consistent with the simulation results.

[0072] In summary, the present invention utilizes voice signals to control the functions of digital programmable metasurfaces in real time, which can effectively realize functions such as wide beam, RCS reduction, vortex waves and beam splitting, while realizing non-contact intelligent control, and will have broad application prospects in acoustic and electromagnetic fusion communications.

[0073] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

[0074] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A voice recognition controlled intelligent electromagnetic metasurface, characterized in that: The intelligent electromagnetic metasurface comprises: A digital programmable metasurface (1) is composed of m×n super subunits (11), each of which comprises: p×q active units (111), a positive voltage bias line (112), a negative voltage bias line (113), a positive metal through hole (114), and a negative metal through hole (115), wherein all active units in the same super subunit share the same reverse bias voltage and have the same reflection coefficient; A voice control system (2), comprising: a voice recognition module (21), a computer (22) and a digital-to-analog conversion circuit (23); The speech recognition module (21) obtains the recognition speech instruction, processes the recognition speech instruction to form corresponding serial port data, and then sends the serial port data to the computer (22). The computer (22) receives and converts the serial port data into a format that can be processed by the digital-to-analog conversion circuit (23), and then sends it to the digital-to-analog conversion circuit (23). The digital-to-analog conversion circuit (23) generates a corresponding voltage sequence to control the digital programmable metasurface (1). The active unit (111) comprises: metal ground(1111); A dielectric substrate (1112) disposed on the upper surface of the metal ground (1111); A first metal patch (1113) and a second metal patch (1114), which are arranged on the upper surface of the dielectric substrate (1112), a recessed portion is provided on one side of the first metal patch (1113), and both wings of the side have a protruding portion, a protruding portion is provided in the middle of one side of the second metal patch (1114), and the protruding portion of the second metal patch (1114) is embedded in the recessed portion of the first metal patch (1113), wherein a gap is provided between the top surface of the protruding portion of the second metal patch (1114) and the bottom surface of the recessed portion of the first metal patch (1113); a variable capacitance diode (1115), which is arranged on the gap, and one end of which is arranged on the upper surface of the first metal patch (1113), and the other end of which is arranged on the upper surface of the second metal patch (1114); Wherein, a first DC bias line (1116) is arranged on both wings of the first metal patch (1113) away from the second metal patch (1114), and a second DC bias line (1117) is arranged on both wings of the second metal patch (1114) away from the first metal patch (1113).

2. The intelligent electromagnetic metasurface controlled by voice recognition according to claim 1, characterized in that: The period of the active unit (111) is L=12 mm, the height of the dielectric substrate (1112) is H=3 mm, the thickness of the metal ground (1111) is 0.018 mm, and the variable capacitance diode (1115) has an adjustable capacitance value in the range of 0.14 to 1.1 pF, and a corresponding reverse bias voltage of 10 to 0 V.

3. The intelligent electromagnetic metasurface controlled by voice recognition according to claim 1, characterized in that: The positive voltage bias line (112) of the super subunit (11) is connected to the first DC bias line (1116) of each active unit (111), and then connected to the positive electrode of the digital-to-analog conversion circuit (23) through the positive metal through hole (114); The negative voltage bias line (113) of the super sub-unit (11) is connected to the second DC bias line (1117) of each active unit (111), and then connected to the negative electrode of the digital-to-analog conversion circuit (23) through the negative metal through hole (115); The positive and negative voltages of each super subunit (11) are independently controlled by a digital-to-analog conversion circuit (23).

4. The intelligent electromagnetic metasurface controlled by voice recognition according to claim 1, characterized in that: The dielectric substrate (1112) is made of F4B, with a dielectric constant of 2.65 and a loss tangent of 0.

001.

5. The intelligent electromagnetic metasurface controlled by voice recognition according to claim 1, characterized in that: The capacitance value of the variable capacitance diode (1115) is controlled in real time by changing the reverse bias voltage at both ends thereof; as the capacitance value changes, the active unit (111) has a different reflection coefficient; Four super subunits (11) with reflection phase differences of 90°, 180° and 270° are represented by four coding states of "00", "01", "10" and "11".

6. The intelligent electromagnetic metasurface controlled by voice recognition according to any one of claims 1 to 5, characterized in that: The digital programmable metasurface (1) generates different reflection beams according to different voice commands, each voice command corresponds to a function, each function corresponds to a coding sequence of the digital programmable metasurface (1), and each coding sequence corresponds to a voltage sequence; The computer (22) stores voltage sequences required for different functions in advance, and the computer (22) selects the voltage sequence according to the serial port data and manipulates the digital-to-analog conversion circuit (23) to control the digital programmable metasurface (1).

7. The intelligent electromagnetic metasurface controlled by voice recognition according to claim 6, characterized in that: The capabilities include: wide beam, RCS reduction, vortex wave and two beams.

8. The intelligent electromagnetic metasurface controlled by voice recognition according to claim 6, characterized in that: The coding sequence is obtained by genetic algorithm optimization.

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