Nonlinear metasurface for generating frequency multiplication harmonic and dynamically modulating harmonic phase

Abstract

The invention discloses a non-linear metasurface capable of generating frequency-doubled harmonic waves and dynamically modulating harmonic wave phases, which is formed by periodically arranging a plurality of frequency-doubled harmonic wave phase reconfigurable units, and each frequency-doubled harmonic wave phase reconfigurable unit can efficiently convert a space incident fundamental frequency signal into a second harmonic wave radiated to the space. And the phase of the second harmonic is independently and dynamically regulated and controlled. Benefited from the independent regulation and control capability of each unit on the phase of the second harmonic, the metasurface can flexibly control the radiation direction of the second harmonic, and can also take the second harmonic as a carrier wave to modulate digital information on the carrier wave and realize wireless transmission. Compared with an existing harmonic wave nonlinear metamaterial, the metamaterial has the advantages of being low in profile, high in harmonic wave generation efficiency and capable of dynamically controlling harmonic waves.

Description

Technical Field

[0001] The present invention belongs to the technical field of novel artificial metasurface arrays, and particularly relates to a nonlinear metasurface that generates second-harmonic waves and dynamically modulates the phase of the harmonic waves. Background Art

[0002] As one of the core research directions in nonlinear science, harmonic generation exhibits unique technical advantages in the microwave frequency band. Nonlinear metamaterials have opened up a new technical path for harmonic generation by directly doubling the frequency of the incident wave in space and radiating it, and have received high attention from scholars at home and abroad in recent years. Research shows that such metamaterials can effectively solve the long-existing phase-matching problem in traditional nonlinear physics, thus giving rise to a variety of innovative microwave harmonic generation metamaterial systems, including double-resonant metamaterials, left-handed metamaterials, and double-near-zero dielectric constant metamaterials, etc., and fruitful research results have been achieved. The latest progress shows that through the metasurface design integrating active frequency doubling chips, although there are problems such as high power consumption, significant thermal effects, and high cost, a significant improvement in harmonic conversion efficiency has been achieved. Based on these breakthroughs, the academic community generally believes that the metamaterial frequency doubling technology will provide important theoretical support and technical inspiration for the innovative development of the next-generation wireless communication system.

[0003] However, although the second-harmonic wave metamaterials show potential in revealing novel physical phenomena, their practical applications still face significant challenges. At present, except for a very small number of active nonlinear metamaterials, the vast majority of passive second-harmonic wave metamaterials have bottleneck problems such as low frequency conversion efficiency, bulky structures, and insufficient ability to manipulate harmonic waves. It is worth noting that in the field of harmonic radars, the second-harmonic wave technology has been successfully applied to scenarios such as snow disaster search and rescue, insect tracking, and building structure detection. However, the existing technology has extremely limited modulation ability for harmonic waves, only supports simple on-off keying (OOK) modulation mode, and lacks effective beamforming and manipulation means. Therefore, improving the generation efficiency of second-harmonic waves and developing advanced harmonic modulation and manipulation technologies will become the key breakthrough point for unleashing the application potential of harmonic backscattering, and has important research value and application prospects. Summary of the Invention

[0004] Object of the Invention: Aiming at the deficiencies of the existing technology, the present invention provides a nonlinear metasurface that generates second-harmonic waves and dynamically modulates the phase of the harmonic waves. Compared with the existing nonlinear harmonic metamaterials, it has the advantages of low profile, high harmonic generation efficiency, and dynamic control of the harmonic wave phase.

[0005] Technical Solution: To achieve the object of the present invention, the technical solution adopted by the present invention is: a nonlinear metasurface that generates second-harmonic waves and dynamically modulates the phase of the harmonic waves, including: an array of second-harmonic wave phase reconfigurable units, which is formed by periodically arranging a plurality of second-harmonic wave phase reconfigurable units.

[0006] As a preferred embodiment of the present invention, the frequency-doubling harmonic phase reconfigurable unit is a three-layer metal and two-layer dielectric structure, including a receiving radiation metal layer, a first dielectric layer, a metal covering layer, a second dielectric layer, and a frequency-doubling phase-shifting circuit module stacked on top of each other from top to bottom.

[0007] As a preferred embodiment of the present invention, the receiving radiation metal layer includes a fundamental frequency receiver, a harmonic emitter, a fundamental frequency microstrip line, and a harmonic microstrip line;

[0008] The fundamental frequency receiver is a square U-shaped metal patch, which is connected to the fundamental frequency microstrip line; the harmonic emitter is a rectangular metal patch inside the square U, which is connected to the harmonic microstrip line;

[0009] The polarization modes of the fundamental frequency receiver and the harmonic emitter are designed to be orthogonal to each other, that is, the polarization state of the emitted harmonic is converted by 90° relative to the incident fundamental frequency wave;

[0010] The fundamental frequency metal rod and the harmonic metal rod penetrate through the first dielectric layer and the second dielectric layer;

[0011] The fundamental frequency metal rod connects the end of the fundamental frequency microstrip line and the input end of the frequency-doubling phase-shifting circuit module, and the harmonic metal rod connects the output end of the frequency-doubling phase-shifting circuit module and the end of the harmonic microstrip line;

[0012] There are two round holes on the metal covering layer. The center position of one round hole is the same as the center position of the fundamental frequency metal rod, and the diameter of the round hole is larger than the diameter of the fundamental frequency metal rod;

[0013] The center position of the other round hole is the same as the center position of the harmonic metal rod, and the diameter of the round hole is larger than the diameter of the harmonic metal rod. The metal covering layer does not contact the fundamental frequency metal rod and the harmonic metal rod.

[0014] As a preferred embodiment of the present invention, the frequency-doubling phase-shifting circuit module includes a harmonic generation circuit and a harmonic phase-shifting circuit, and the harmonic generation circuit and the harmonic phase-shifting circuit are cascaded;

[0015] The harmonic generation circuit is composed of several microstrip lines and Schottky diodes;

[0016] Between the input end of the harmonic generation circuit and the anode of the Schottky diode, there are a first series microstrip line, a parallel termination microstrip line, and a second series microstrip line in sequence;

[0017] Between the cathode of the Schottky diode and the output end of the harmonic generation circuit, there are a parallel termination open-circuit microstrip line, a third series microstrip line, a parallel termination short-circuit microstrip line, and a fourth series microstrip line in sequence;

[0018] The harmonic phase shift circuit is an orthogonal bridge reflection type phase shift circuit; after the harmonic signal generated by the harmonic generation circuit passes through the harmonic phase shift circuit, a phase shift is formed.

[0019] As a preferred solution of the present invention, the harmonic phase shift circuit of each frequency-doubled harmonic phase reconfigurable unit is connected to the output port of the digital control module;

[0020] The phase of the frequency-doubled harmonic generated by each frequency-doubled harmonic phase reconfigurable unit is independently controlled by the digital signal output by the digital control module.

[0021] Beneficial effects: Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0022] (1) Most of the existing frequency-doubled harmonic nonlinear metamaterials are three-dimensional structures. The present invention adopts a two-dimensional metasurface structure, which has an extremely low profile.

[0023] (2) The harmonic generation efficiency of the existing passive frequency-doubled harmonic nonlinear metamaterials is low. The frequency-doubled harmonic generation efficiency of the nonlinear metasurface of the present invention is significantly improved.

[0024] (3) The existing frequency-doubled harmonic nonlinear metamaterials do not have the function of harmonic manipulation. The nonlinear metasurface of the present invention can perform real-time dynamic regulation on the harmonic phase, so as to have the ability of harmonic beam and information modulation.

[0025] (4) The present invention can be prepared by using the mature printed circuit board processing technology and component surface mounting technology, and has the advantages of small processing difficulty and low cost. Description of the Drawings

[0026] Figure 1 It is a top view of a nonlinear metasurface for generating frequency-doubled harmonics and dynamically modulating the harmonic phase according to the present invention.

[0027] Figure 2 It is a three-dimensional structure schematic diagram of the frequency-doubled harmonic phase reconfigurable unit 1 in the embodiment of the present invention.

[0028] Figure 3 It is a structure schematic diagram of the frequency-doubled phase shift circuit module 6.

[0029] Figure 4 It is the fundamental frequency to second harmonic conversion efficiency of the harmonic generation circuit 61 in the embodiment of the present invention.

[0030] Figure 5 It is the transmission amplitude and transmission phase of the harmonic phase shift circuit 62 in the embodiment of the present invention.

[0031] Figure 6The radiation pattern of the fundamental frequency receiver in the embodiment of the present invention at the operating frequency of 2.4 GHz and the harmonic emitter at the operating frequency of 4.8 GHz.

[0032] Figure 7 The measured result of the coupling effect between the fundamental frequency receiver 21 and the harmonic emitter 23.

[0033] Figure 8 The sample photo of a nonlinear metasurface that generates frequency-doubled harmonics and dynamically modulates the harmonic phase in the embodiment of the present invention.

[0034] Figure 9 The fundamental frequency to second harmonic conversion efficiency of the sample in the embodiment of the present invention.

[0035] Figure 10 The beam steering performance of the nonlinear metasurface sample in the embodiment of the present invention for the second harmonic under different digital coding controls.

[0036] Figure 11 The experimental photos and communication experiment results of the nonlinear metasurface sample in the embodiment of the present invention applied as a harmonic transmitter and an information modulator in a wireless communication system.

[0037] Marking description in the figure: 1. Frequency-doubled harmonic phase reconfigurable unit; 2. Receiving radiation metal layer; 21. Fundamental frequency receiver; 22. Fundamental frequency microstrip line; 23. Harmonic emitter; 24. Harmonic microstrip line; 3. First dielectric layer; 4. Metal covering layer; 5. Second dielectric layer; 6. Frequency-doubled phase shift circuit module; 61. Harmonic generation circuit; 62. Harmonic phase shift circuit; 63. Schottky diode; 64. First series microstrip line; 65. Parallel terminal microstrip line; 66. Second series microstrip line; 67. Parallel terminal open microstrip line; 68. Third series microstrip line; 69. Parallel terminal shorted microstrip line; 610. Fourth series microstrip line; 7. Fundamental frequency metal rod; 8. Harmonic metal rod. Detailed implementation manners

[0038] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0039] As Figure 1As shown in the figure, a non - linear metasurface for generating second - harmonic and dynamically modulating the harmonic phase according to the present invention includes an array of second - harmonic phase - reconfigurable units. The array is formed by arranging a number of second - harmonic phase - reconfigurable units 1 in a periodic pattern. Each second - harmonic phase - reconfigurable unit 1 has a three - layer metal and two - layer dielectric structure, including a receiving - radiation metal layer 2, a first dielectric layer 3, a metal - covering layer 4, a second dielectric layer 5, and a second - harmonic phase - shifting circuit module 6, which are stacked in sequence from top to bottom. The fundamental - frequency receiver 21 located on the receiving - radiation metal layer 2 receives the incident fundamental - frequency signal in space and converts the fundamental - frequency signal into a guided wave. The fundamental - frequency guided wave enters the second - harmonic phase - shifting circuit module 6 via the fundamental - frequency metal rod 7. The second - harmonic phase - shifting circuit module 6 generates the second - harmonic under the excitation of the fundamental - frequency signal and phase - shifts the second - harmonic. The second - harmonic generated by the second - harmonic phase - shifting circuit module 6 enters the receiving - radiation metal layer 2 via the harmonic metal rod 8 and is radiated into space by the harmonic emitter 23. Compared with the existing harmonic non - linear metamaterials, the present invention has a higher harmonic generation efficiency, can real - time regulate the harmonic phase through digital signals, thereby realizing the dynamic regulation of the harmonic beam, and can also use the harmonic as a carrier to achieve harmonic scattering communication.

[0040] The following gives a preferred embodiment of the above - mentioned embodiment regarding a non - linear metasurface for generating second - harmonic and dynamically modulating the harmonic phase:

[0041] In the present invention, the array of second - harmonic phase - reconfigurable units is composed of 8 rows and 4 columns of second - harmonic phase - reconfigurable units 1, as Figure 1 shown. As Figure 2As shown in the figure, the second-harmonic phase reconfigurable unit 1 has a three-layer metal and two-layer dielectric structure, and includes a receiving radiation metal layer 2, a first dielectric layer 3, a metal covering layer 4, a second dielectric layer 5, and a second-harmonic phase-shifting circuit module 6 that are stacked on top of each other from top to bottom. The receiving radiation metal layer 2 includes a fundamental-frequency receiver 21, a harmonic emitter 23, a fundamental-frequency microstrip line 22, and a harmonic microstrip line 24. Among them, the fundamental-frequency receiver 21 is a square U-shaped metal patch, which is connected to the fundamental-frequency microstrip line 22; the harmonic emitter 23 is a rectangular metal patch inside the square U, which is connected to the harmonic microstrip line 24. To minimize the coupling between the fundamental-frequency receiver 21 and the harmonic emitter 23, the polarization modes of the fundamental-frequency receiver 21 and the harmonic emitter 23 are designed to be orthogonal to each other - that is, the polarization state of the emitted harmonic has a 90° conversion relative to the incident fundamental-frequency wave. The fundamental-frequency metal rod 7 and the harmonic metal rod 8 penetrate through the first dielectric layer 3 and the second dielectric layer 5. Among them, the fundamental-frequency metal rod 7 connects the end of the fundamental-frequency microstrip line 22 and the input end of the second-harmonic phase-shifting circuit module 6, and the harmonic metal rod 8 connects the output end of the second-harmonic phase-shifting circuit module 6 and the end of the harmonic microstrip line 24. There are two circular holes on the metal covering layer 4. The center position of one circular hole is the same as the center position of the fundamental-frequency metal rod 7, and the diameter of the circular hole is larger than the diameter of the fundamental-frequency metal rod 7; the center position of the other circular hole is the same as the center position of the harmonic metal rod 8, and the diameter of the circular hole is larger than the diameter of the harmonic metal rod 8. The metal covering layer 4 does not contact the fundamental-frequency metal rod 7 and the harmonic metal rod 8. As Figure 3 shown in the figure, the second-harmonic phase-shifting circuit module 6 includes a harmonic generation circuit 61 and a cascaded harmonic phase-shifting circuit 62. The harmonic generation circuit 61 is composed of several microstrip lines and Schottky diodes 63. Between the input end of the harmonic generation circuit 61 and the anode of the Schottky diode 63 are a first series microstrip line 64, a shunt termination microstrip line 65, and a second series microstrip line 66 in sequence; between the cathode of the Schottky diode 63 and the output end of the circuit are a shunt termination open microstrip line 67, a third series microstrip line 68, a shunt termination short microstrip line 69, and a fourth series microstrip line 610 in sequence. The harmonic phase-shifting circuit 62 is an orthogonal bridge reflection type phase-shifting circuit. After the harmonic signal generated by the harmonic generation circuit 61 passes through the harmonic phase-shifting circuit 62, a certain phase shift is formed. The harmonic phase-shifting circuit 62 of each second-harmonic phase reconfigurable unit 1 is connected to the output port of the digital control module (there are two PIN diodes on the orthogonal bridge reflection type phase-shifting circuit, and the positive poles of the diodes are connected to the output port of the digital control module. When the module outputs a high level or a low level (i.e., the digital signal 1 or 0), the phase-shifting circuit causes the phase of the harmonic to change accordingly). The phase of the second-harmonic generated by each second-harmonic phase reconfigurable unit 1 is independently controlled by the digital signal output by the digital control module.

[0042] To verify the performance of the second-harmonic phase-shifting circuit module 6 in the present invention, a circuit sample was fabricated in this embodiment and its performance was tested.Figure 4 It shows the change of the fundamental frequency to second harmonic efficiency measured by the circuit module within the input power range from -30 dBm to 0 dBm. It can be found that when the power is increased to near -10 dBm, the efficiency is significantly enhanced, reaching the highest value of 4.8% at the 2.4 GHz frequency point when the input power is -6 dBm. This measured result highly coincides with the simulation trend in the figure. This change in efficiency is mainly due to the non-linear response characteristics of the Schottky diode: at low power densities, the diode may not be fully turned on, resulting in poor rectification effect and reduced conversion efficiency; as the power density increases, the diode enters the optimal working range to achieve higher efficiency; but when the power density exceeds the critical value, the diode tends to be in a saturated state, causing the efficiency growth to stagnate or even decline.

[0043] Figure 5 It shows the magnitude and transmission phase of the transmission coefficient of the circuit module for the second harmonic. At the 4.8 GHz frequency point, the magnitudes of the two states are -1.5 dB and -1.36 dB respectively, and the phase difference reaches 181°; within the frequency band from 4.0 to 5.4 GHz, the phase difference is stably maintained within the range of 180° ± 20°, and this performance fully meets the 1-bit regulation requirement for harmonics.

[0044] To verify the performance of the receiving radiation metal layer 2 in the present invention, a sample was fabricated in this embodiment and its performance was tested. Figure 6 It shows the measured far-field radiation patterns of the fundamental frequency receiver 21 at 2.4 GHz and the harmonic transmitter 23 at 4.8 GHz in the E-plane and H-plane. The test results show that the main lobe of the receiving end points to the normal direction and the gain reaches 5.3 dBi; the gain of the transmitting end is 6.9 dBi, and due to its offset position relative to the center of the structure, there is a 12° normal offset of the main lobe in the E-plane. Figure 7 It shows the measured results of the coupling effect between the fundamental frequency receiver 21 and the harmonic transmitter 23: the coupling degree at the 2.4 GHz frequency point is lower than -14 dB, and the coupling degree at the 4.8 GHz frequency point reaches -26 dB, thus verifying their extremely low mutual coupling effect.

[0045] To verify the performance of a non-linear metasurface for generating frequency-doubled harmonics and dynamically modulating the harmonic phase in the present invention, a sample was fabricated in this embodiment and tested. The front and back photos of the sample are as Figure 8 shown, including an array composed of a frequency-doubled harmonic phase reconfigurable unit with 8 rows and 4 columns. Figure 9 It shows the relationship between the efficiency of the fundamental frequency conversion to the second harmonic of the metasurface sample obtained by the test and the fundamental frequency power density. The results show that as the power density increases, the conversion efficiency shows a trend of first increasing and then decreasing. When the power density reaches about 0.03 mW / cm 2When the system operates at a fundamental frequency of 2.32 GHz, it achieves a peak efficiency of 2.46%. At a frequency of 2.4 GHz, the maximum conversion efficiency is 1.82%. Compared with traditional harmonic metamaterials, the present invention can still maintain a highly competitive conversion efficiency at such a low fundamental frequency power density.

[0046] Subsequently, the harmonic scattering characteristics of the metasurface sample under digital sequence control were experimentally tested. Figure 10 The measured and CST-simulated normalized far-field scattering patterns at a frequency of 4.8 GHz are shown, and they are in good agreement. When the coding sequence is set to 00000000 or 11111111, the second-harmonic signal should radiate perpendicular to the metasurface. Due to the blocking effect caused by the transmitting antenna placed in the normal direction, the harmonic signal undergoes secondary scattering to form a divergent beam, as shown in (a) of Figure 10 . Figure 10 (b), (c), and (d) of

[0047] correspond to the patterns of the coding sequences 00001111, 00110011, and 01010101, respectively, all showing the characteristic of beam splitting. The measured deflection angles are ±12.0°, ±22.8°, and ±51.6°, respectively, which are highly consistent with the simulation results. These results verify the ability of the metasurface to flexibly manipulate the second-harmonic scattering characteristics through phase modulation.

[0047] To fully utilize the phase modulation ability of the metasurface for second harmonics in the present invention, it is applied as a harmonic transmitter and information modulator in a wireless communication system, as shown in (a) of Figure 11 . At the receiving end of the communication system, a software-defined radio device is used to recover digital information. Under the control of a field-programmable gate array (FPGA), the metasurface sample uses the second harmonic as a carrier and modulates the 4.8 GHz second harmonic using a binary phase shift keying (BPSK) scheme, which is achieved by directly controlling the physical 1-bit phase state of the second harmonic. The switching frequency of the control signal is set to 1 MHz. Since the phase modulation is directly based on digital coding, the data transmission rate reaches 1 Mbps. In addition, as shown in (b) of Figure 11 , the metasurface is designed with a phase gradient of π / unit, so the modulated second-harmonic signal is directionally deflected to about ±51° directions. The receiving horn antenna is placed in the optimal direction to obtain the best effect. Figure 11 (c) of Figure 11 shows the demodulated constellation diagram, with an error vector magnitude (EVM) of 39.25%, presenting high-quality characteristics and good image recovery effect. In contrast, when the receiving horn antenna is blocked by a metal plate, as shown in (d) of

[0048] In summary, the present invention proposes a reconfigurable power-dependent absorbing metasurface for surface waves, including: an electrically tunable unit array and a surface wave intensity concentration induction control module, which uses a centralized induction control method to collect the surface wave power intensity and achieve the absorption rate control of the system. This is a flexible and adjustable surface electromagnetic wave absorption solution, which has the advantages of wide frequency band, large absorption rate variation range, low cost, etc. At the same time, the dynamic range, absorption rate regulation range and the switch of the whole system can be customized, so it can meet the requirements of various surface wave shielding scenarios.

[0049] In the specification provided herein, a large number of specific details are set forth. It will be understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail so as not to obscure an understanding of this description.

[0050] In addition, those skilled in the art will appreciate that although some embodiments described herein include certain features contained in other embodiments but not others, the combinations of features of different embodiments are equally within the scope of protection of the present invention and form different embodiments. For example, in the above embodiments, those skilled in the art can use them in combination according to the known technical solutions and the technical problems to be solved by this application.

[0051] The above are only preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art of this patent can make some changes or modifications to equivalent embodiments by using the technical content prompted above within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the present invention.

Claims

1. A nonlinear metasurface that generates frequency - doubled harmonics and dynamically modulates the harmonic phase, characterized in that, Including: An array of frequency-doubled harmonic phase reconfigurable units, which is formed by arranging a number of frequency-doubled harmonic phase reconfigurable units in a periodic manner.

2. The non-linear metasurface according to claim 1, wherein The frequency-doubled harmonic phase reconfigurable unit is a three-layer metal and two-layer dielectric structure, including a receiving radiation metal layer, a first dielectric layer, a metal covering layer, a second dielectric layer, and a frequency-doubling phase-shifting circuit module that are stacked on top of each other in sequence from top to bottom.

3. The non-linear metasurface according to claim 2, wherein The receiving radiation metal layer includes a fundamental frequency receiver, a harmonic emitter, a fundamental frequency microstrip line, and a harmonic microstrip line; The fundamental frequency receiver is a square U-shaped metal patch, which is connected to the fundamental frequency microstrip line; the harmonic emitter is a rectangular metal patch inside the square U-shaped metal patch, which is connected to the harmonic microstrip line; The polarization modes of the fundamental frequency receiver and the harmonic emitter are designed to be orthogonal to each other, that is, the polarization state of the emitted harmonic has a 90° conversion relative to the incident fundamental frequency wave; A fundamental frequency metal rod and a harmonic metal rod penetrate through the first dielectric layer and the second dielectric layer; The fundamental frequency metal rod connects the end of the fundamental frequency microstrip line and the input end of the frequency-doubling phase-shifting circuit module, and the harmonic metal rod connects the output end of the frequency-doubling phase-shifting circuit module and the end of the harmonic microstrip line; There are two round holes on the metal covering layer. The center position of one round hole is the same as the center position of the fundamental frequency metal rod, and the diameter of the round hole is larger than the diameter of the fundamental frequency metal rod; The center position of the other round hole is the same as the center position of the harmonic metal rod, and the diameter of the round hole is larger than the diameter of the harmonic metal rod. The metal covering layer does not contact the fundamental frequency metal rod and the harmonic metal rod.

4. The nonlinear metasurface according to any one of claims 1-3, characterized in that, The frequency-doubling phase-shifting circuit module includes a harmonic generation circuit and a harmonic phase-shifting circuit, and the harmonic generation circuit and the harmonic phase-shifting circuit are cascaded; The harmonic generation circuit is composed of a number of microstrip lines and Schottky diodes; Between the input end of the harmonic generation circuit and the anode of the Schottky diode are a first series microstrip line, a shunt termination microstrip line, and a second series microstrip line in sequence; Between the cathode of the Schottky diode and the output end of the harmonic generation circuit are a shunt termination open-circuit microstrip line, a third series microstrip line, a shunt termination short-circuit microstrip line, and a fourth series microstrip line in sequence; The harmonic phase-shifting circuit is an orthogonal bridge-type reflection phase-shifting circuit; after the harmonic signal generated by the harmonic generation circuit passes through the harmonic phase-shifting circuit, a phase shift is formed.

5. The nonlinear metasurface according to claim 4, wherein The harmonic phase-shifting circuit of each frequency-doubled harmonic phase reconfigurable unit is connected to the output port of the digital control module; The phase of the frequency-doubled harmonic generated by each frequency-doubled harmonic phase reconfigurable unit is independently controlled by the digital signal output by the digital control module.

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