Metasurface modulation method of a transmission array antenna

Abstract

The application discloses a metasurface regulation method of a transmission array antenna. In the method, high aperture efficiency and low sidelobe characteristics are realized through phase modulation of two electromagnetic metasurface planes. The first metasurface plane realizes the Chebyshev radiation field aperture distribution required by the low sidelobe characteristics through phase modulation, and the phase control also avoids energy loss in the low sidelobe characteristic design process, thereby realizing the characteristics of high aperture efficiency. The second electromagnetic metasurface plane realizes the high-gain antenna beam through phase modulation, and controls the pointing direction of the whole antenna beam, thereby realizing the required radiation direction. The method can avoid the energy loss generated in the related art design method of low sidelobe characteristics, thereby realizing high aperture efficiency under the condition of designing low sidelobe.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless communication, and in particular to a metasurface regulation method of a transmissive array antenna. BACKGROUND

[0002] As a radio frequency front end of a wireless communication system, an antenna is a connecting device of signals in a circuit and spatial radiation signals, which can convert signals in the circuit into spatial radiation signals capable of spatial propagation, and can also receive spatial radiation signals to convert them into circuit signals. Therefore, the performance of the antenna will directly determine the quality of the entire communication.

[0003] Compared with a phased array antenna, a transmissive array antenna based on an electromagnetic metasurface has many advantages such as low profile and low cost, and has a wider application scenario. The transmissive array antenna can realize various types of antenna design by regulating the electric field of a feed source through the electromagnetic metasurface structure on the transmissive array surface.

[0004] The aperture efficiency of an antenna is defined as the ratio of the effective aperture of the antenna receiving and radiating to the physical actual aperture. The effective aperture of the antenna is defined as the area perpendicular to the direction of the incident radio wave and effectively intercepting the energy of the incident radio wave. A higher aperture efficiency means that the antenna can achieve higher antenna gain under the condition of a smaller physical actual aperture, thereby realizing the propagation of a radiated signal at a farther distance. The side lobe of an antenna affects the signal acquisition and anti-interference ability of the antenna, and therefore the side lobe level is also an important indicator for measuring the performance of the antenna.

[0005] At present, the method for designing the low side lobe characteristic of an antenna generally needs to specially design the amplitude distribution on the antenna radiation aperture, such as the Chebyshev amplitude distribution and the Taylor amplitude distribution, to achieve the required side lobe level.

[0006] In the related art, in the design of a low side lobe characteristic of a transmissive array antenna based on an electromagnetic metasurface, an electromagnetic metasurface structure capable of independently regulating the amplitude and phase is often used. The unit realizes the required low side lobe aperture amplitude distribution by regulating the amplitude, and realizes the high gain antenna beam by regulating the phase. However, the design of the electromagnetic metasurface with independent regulation of the amplitude and phase is relatively complex, and the process of regulating the amplitude causes energy loss, thereby resulting in a loss of the aperture efficiency of the antenna. SUMMARY

[0007] Therefore, the present application provides a metasurface regulation method of a transmissive array antenna, which can overcome the problem of the loss of the aperture efficiency of a conventional low side lobe transmissive array antenna design, and maintain the high aperture efficiency characteristic of the antenna in the process of designing the low side lobe characteristic.

[0008] The present application provides a metasurface regulation method of a transmissive array antenna, comprising:

[0009] a first metasurface plane, a second metasurface plane are arranged in sequence from near to far on a radiation path of a horn feed of an antenna;

[0010] an incident electric field distribution of the horn feed is acquired radiated to the first metasurface plane;

[0011] an exit electric field distribution of the first metasurface plane is obtained based on a particle swarm optimization algorithm according to the incident electric field distribution of the first metasurface plane and an amplitude distribution required by a target side lobe;

[0012] an incident electric field distribution of the second metasurface plane is obtained based on a physical optics electromagnetic algorithm according to the exit electric field distribution of the first metasurface plane and the incident electric field distribution of the first metasurface plane;

[0013] an exit electric field distribution of the second metasurface plane is obtained by regulating the incident electric field distribution of the second metasurface plane according to a phase distribution required by a target aperture efficiency;

[0014] a first target regulation phase for the first metasurface plane is determined as a corresponding phase distribution of the incident electric field distribution of the first metasurface plane and a corresponding phase distribution of the exit electric field distribution of the first metasurface plane;

[0015] a second target regulation phase for the second metasurface plane is determined as a corresponding phase distribution of the incident electric field distribution of the second metasurface plane.

[0016] Optionally, the incident electric field distribution of the first metasurface plane is acquired through simulation of full-wave electromagnetic simulation software CST.

[0017] Optionally, the exit electric field distribution of the first metasurface plane is obtained, specifically including:

[0018] a corresponding phase distribution of the exit electric field distribution of the first metasurface plane in a partial region is initialized;

[0019] the phase distribution is extended to all regions of the first metasurface plane through mirroring to form an exit electric field phase distribution of the first metasurface plane;

[0020] the exit electric field phase distribution of the first metasurface plane is combined with an exit electric field amplitude distribution of the first metasurface plane to form an exit electric field distribution of the first metasurface plane, wherein the exit electric field amplitude distribution of the first metasurface plane is the same as a corresponding amplitude distribution of the incident electric field of the first metasurface plane.

[0021] Optionally, the step of obtaining the incident electric field distribution of the second metasurface plane further includes:

[0022] the exit electric field distribution of the first metasurface plane is optimized.

[0023] Optionally, the optimization process specifically includes:

[0024] The incident electric field amplitude distribution and Chebyshev amplitude distribution of the second metasurface plane, obtained from the current value of the emitted electric field distribution of the first metasurface plane, are evaluated using a preset fitness function, and the current value is updated.

[0025] Iterate over the current value to obtain the optimized output electric field distribution of the first metasurface plane.

[0026] Optionally, the incident electric field distribution on the second metasurface plane can be controlled, specifically as follows:

[0027] The phase distribution corresponding to the incident electric field distribution on the second metasurface plane is adjusted until the phase distribution is a preset constant.

[0028] Optionally,

[0029] The amplitude distribution corresponding to the incident electric field distribution on the first metasurface plane is specifically defined as follows:

[0030]

[0031] x1∈[-L1 / 2,L1 / 2],y1∈[-L1 / 2,L1 / 2]

[0032] Where L1 is the side length of the first metasurface plane, x1 is the abscissa value in the two-dimensional coordinate system established by the center of the first metasurface plane, and y1 is the ordinate value in the two-dimensional coordinate system established by the center of the first metasurface plane. The incident electric field amplitude corresponding to the horizontal and vertical coordinates of the first metasurface plane.

[0033] The phase distribution corresponding to the incident electric field distribution on the first metasurface plane is specifically defined as follows:

[0034]

[0035] x1∈[-L1 / 2,L1 / 2],y1∈[-L1 / 2,L1 / 2]

[0036] Where L1 is the side length of the first metasurface plane, x1 is the abscissa value in the two-dimensional coordinate system established by the center of the first metasurface plane, and y1 is the ordinate value in the two-dimensional coordinate system established by the center of the first metasurface plane. The incident electric field phase values ​​are the horizontal and vertical coordinates corresponding to the first metasurface plane.

[0037] Optionally,

[0038] The amplitude distribution required for the target sidelobe is defined as follows:

[0039] |E 切比雪夫 (x2,y2)|

[0040] x2∈[-L2 / 2,L2 / 2],y2∈[-L2 / 2,L2 / 2]

[0041] Where L2 is the side length of the second metasurface plane, x2 is the abscissa value in the two-dimensional coordinate system established at the center of the second metasurface plane, y2 is the ordinate value in the two-dimensional coordinate system established at the center of the second metasurface plane, |E 切比雪夫 (x2,y2)| represents the Chebyshev electric field amplitude corresponding to the horizontal and vertical coordinates on the second metasurface plane;

[0042] The phase corresponding to the emitted electric field distribution on the first metasurface plane is defined as:

[0043]

[0044] x1∈[-L1 / 2,L1 / 2],y1∈[-L1 / 2,L1 / 2]

[0045] Where L1 is the side length of the first metasurface plane, x1 is the abscissa value in the two-dimensional coordinate system established by the center of the first metasurface plane, and y1 is the ordinate value in the two-dimensional coordinate system established by the center of the first metasurface plane. The phase value of the emitted electric field corresponding to the horizontal and vertical coordinates of the first metasurface plane;

[0046] The amplitude distribution corresponding to the emitted electric field distribution on the first metasurface plane is specifically defined as follows:

[0047]

[0048] x1∈[-L1 / 2,L1 / 2],y1∈[-L1 / 2,L1 / 2]

[0049] Where L1 is the side length of the first metasurface plane, x1 is the abscissa value in the two-dimensional coordinate system established by the center of the first metasurface plane, and y1 is the ordinate value in the two-dimensional coordinate system established by the center of the first metasurface plane. The amplitude of the emitted electric field is the horizontal and vertical coordinates corresponding to the first metasurface plane;

[0050] The amplitude distribution corresponding to the incident electric field distribution of the second metasurface plane is defined as follows:

[0051]

[0052] x2∈[-L2 / 2,L2 / 2],y2∈[-L2 / 2,L2 / 2]

[0053] Where L2 is the side length of the second metasurface plane, x2 is the abscissa value in the two-dimensional coordinate system established at the center of the second metasurface plane, and y2 is the ordinate value in the two-dimensional coordinate system established at the center of the second metasurface plane. The electric field values ​​corresponding to the horizontal and vertical coordinates on the second metasurface plane;

[0054] The fitness function is defined as:

[0055]

[0056] x2∈[-L2 / 2,L2 / 2],y2∈[-L2 / 2,L2 / 2]

[0057] Where L2 is the side length of the second metasurface plane, x2 is the abscissa value in the two-dimensional coordinate system established at the center of the second metasurface plane, and y2 is the ordinate value in the two-dimensional coordinate system established at the center of the second metasurface plane.

[0058] Optionally,

[0059] The phase distribution corresponding to the incident electric field distribution on the second metasurface plane is defined as follows:

[0060]

[0061] x2∈[-L2 / 2,L2 / 2],y2∈[-L2 / 2,L2 / 2]

[0062] Where L2 is the side length of the second metasurface plane, x2 is the abscissa value in the two-dimensional coordinate system established at the center of the second metasurface plane, and y2 is the ordinate value in the two-dimensional coordinate system established at the center of the second metasurface plane. The electric field phase on the second metasurface plane corresponding to the horizontal and vertical coordinates is denoted as .

[0063] Optionally,

[0064] The first target modulation phase is defined as

[0065]

[0066] x1∈[-L1 / 2,L1 / 2],y1∈[-L1 / 2,L1 / 2]

[0067] Where L1 is the side length of the first metasurface plane, x1 is the abscissa value in the two-dimensional coordinate system established at the center of the first metasurface plane, y1 is the ordinate value in the two-dimensional coordinate system established at the center of the first metasurface plane, and φ S1 (x1, y1) represents the modulated phase of the horizontal and vertical coordinates corresponding to the first metasurface plane;

[0068] The second target regulation phase is defined as

[0069]

[0070] x2∈[-L2 / 2,L2 / 2],y2∈[-L2 / 2,L2 / 2]

[0071] Where L2 is the side length of the second metasurface plane, x2 is the abscissa value in the two-dimensional coordinate system established at the center of the second metasurface plane, y2 is the ordinate value in the two-dimensional coordinate system established at the center of the second metasurface plane, and φ S2 (x2, y2) represents the modulated phase of the horizontal and vertical coordinates corresponding to the second metasurface plane.

[0072] The metasurface control method for the transmission array antenna provided above, compared with the control methods of related technologies, adopts the amplitude and phase separation control metasurface structure to achieve the required low sidelobe aperture electric field distribution. By introducing a new electromagnetic metasurface plane for phase control, energy is redistributed to achieve the required low sidelobe aperture electric field distribution. Thus, while achieving the low sidelobe design, energy loss is avoided and ultra-high aperture efficiency is achieved. At the same time, this design also reduces the difficulty of metasurface structure design, requiring only a basic phase-controlled metasurface structure to complete the design. Attached Figure Description

[0073] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0074] Figure 1 This is a schematic diagram of the structure of the transmission array antenna involved in the control method disclosed in the embodiments of this application.

[0075] Figure 2 This is a schematic diagram of the incident electric field amplitude and phase of the horn feed radiation on the first metasurface plane as disclosed in the embodiments of this application.

[0076] Figure 3 This refers to the Chebyshev amplitude distribution disclosed in the embodiments of this application.

[0077] Figure 4 This is a schematic diagram of the particle swarm optimization algorithm disclosed in the embodiments of this application.

[0078] Figure 5 This is a phase mirror diagram of the optimized calculation process disclosed in the embodiments of this application.

[0079] Figure 6 This is a phase diagram of the emitted electric field distribution of the first electromagnetic metasurface plane disclosed in the embodiments of this application.

[0080] Figure 7 This is a schematic diagram of the amplitude and phase of the incident electric field on the second metasurface plane after phase modulation by the first metasurface plane, as disclosed in the embodiments of this application.

[0081] Figure 8 This is a schematic diagram of the optimized first metasurface planar phase distribution disclosed in the embodiments of this application.

[0082] Figure 9 This is a schematic diagram of the optimized second metasurface planar phase distribution disclosed in the embodiments of this application.

[0083] The components in the diagram are labeled as follows:

[0084] 10 - First metasurface plane; 20 - Second metasurface plane; 30 - Horn feed. Detailed Implementation

[0085] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0086] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0087] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0088] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0089] Before introducing the technical solution of this application, it is necessary to explain the background of the invention.

[0090] It is common practice in related technologies that, in the design of low sidelobe characteristics based on electromagnetic metasurface transmission array antennas, electromagnetic metasurface structures with independently adjustable amplitude and phase are often used. This element achieves the required low sidelobe aperture amplitude distribution by adjusting the amplitude and achieves a high-gain antenna beam by adjusting the phase. However, the design of electromagnetic metasurfaces with independently adjustable amplitude and phase is relatively complex, and the process of adjusting the amplitude involves energy loss, which leads to a loss of antenna aperture efficiency.

[0091] Based on the applicant's awareness of the aforementioned challenges, the applicant proposes a metasurface modulation method for transmission array antennas. Compared to the traditional amplitude modulation method that uses energy loss to achieve the radiation aperture amplitude distribution corresponding to low sidelobes, this application introduces an additional metasurface plane. By using the phase modulation of the electromagnetic metasurface structure on this plane, the energy distribution is redistributed to achieve the aperture amplitude distribution required for low sidelobes. This avoids energy loss and maintains high aperture efficiency while achieving low sidelobes. The specific process of obtaining the phase modulation distribution of the newly introduced metasurface structure adopts a particle swarm optimization algorithm.

[0092] Furthermore, this application introduces a new electromagnetic metasurface plane on top of the traditional single-layer transmission array antenna structure with low sidelobes. Phase modulation of this plane achieves the aperture amplitude distribution corresponding to the low sidelobes. This reduces the difficulty of electromagnetic metasurface design, eliminating the need for independently modulated amplitude and phase electromagnetic metasurfaces; a basic phase-modulated electromagnetic metasurface suffices. Additionally, it improves aperture efficiency by avoiding energy loss. Thus, this invention is established.

[0093] refer to Figure 1 The transmittance array antenna of this application has a general antenna structure of a horn feed 30, and a first metasurface plane 10 and a second metasurface plane 20 are arranged on the radiation path of the horn feed 30. The first metasurface plane 10 and the second metasurface plane 20 are distributed from near to far. The metasurface control method involved in this application is to control the phase of the first metasurface plane 10 and the second metasurface plane 20.

[0094] The metasurface manipulation method for a transmission array antenna disclosed in this application includes:

[0095] S1. A first metasurface plane 10 and a second metasurface plane 20 are arranged sequentially from near to far along the radiation path of the antenna's horn feed 30.

[0096] Here, the positions of the first metasurface plane 10 and the second metasurface plane 20 are arbitrarily set and selected according to the total volume of space reserved for the antenna in the actual situation. The orientation is directly above the initial horn feed 30, and the plane normal is parallel to the horn opening orientation.

[0097] It should be understood that, since the first metasurface plane 10 and the second metasurface plane 20 are arranged sequentially from near to far, the electromagnetic field (referred to as the electric field) formed from the horn feed 30 first reaches the first metasurface plane 10, that is, the incident electric field distribution of the first metasurface plane 10. After passing through the first metasurface plane 10, it is emitted to form the emitted electric field distribution of the first metasurface plane 10. Then it is incident on the surface of the second metasurface plane 20, that is, the incident electric field distribution of the second metasurface plane 20. Finally, after passing through the second metasurface plane 20, it is emitted to form the emitted electric field distribution of the second metasurface plane 20.

[0098] Here, it is already known that the electric field distribution adopts a complex number. The electric field distribution, radiated by the horn feed 30 and acting upon the first metasurface plane 10 and the second metasurface plane 20, comprises two parts: amplitude distribution and phase distribution. Based on this, the electric field distribution after passing through the first metasurface plane 10 and the second metasurface plane 20 has eight distribution parameters: amplitude distribution corresponding to the incident electric field distribution of the first metasurface plane 10, phase distribution corresponding to the incident electric field distribution of the first metasurface plane 10, amplitude distribution corresponding to the emitted electric field distribution of the first metasurface plane 10, phase distribution corresponding to the emitted electric field distribution of the first metasurface plane 10, amplitude distribution corresponding to the emitted electric field distribution of the second metasurface plane 20, phase distribution corresponding to the incident electric field distribution of the second metasurface plane 20, amplitude distribution corresponding to the emitted electric field distribution of the first metasurface plane 10, and phase distribution corresponding to the emitted electric field distribution of the first metasurface plane 10.

[0099] As a demonstration site, the amplitude can remain unchanged during actual control. Specifically, the amplitude distribution of the incident electric field of the first metasurface plane 10 and the amplitude distribution of the emitted electric field of the first metasurface plane 10 can be the same, as can the amplitude distribution of the incident electric field of the second metasurface plane 20 and the amplitude distribution of the emitted electric field of the second metasurface plane 20.

[0100] S2. Obtain the incident electric field distribution radiated from the horn feed 30 onto the first metasurface plane 10.

[0101] As an example, the incident electric field distribution of the first metasurface plane 10 was obtained through simulation using the full-wave electromagnetic simulation software CST.

[0102] As an example, refer to Figure 2 The amplitude distribution corresponding to the incident electric field distribution of the first metasurface plane 10 is specifically defined as follows:

[0103]

[0104] x1∈[-L1 / 2,L1 / 2],y1∈[-L1 / 2,L1 / 2]

[0105] Where L1 can be 200 mm, which is the side length of the first metasurface plane 10; x1 is the abscissa value on the two-dimensional coordinate system established at the center of the first metasurface plane 10; and y1 is the ordinate value on the two-dimensional coordinate system established at the center of the first metasurface plane 10. The incident electric field amplitude is the horizontal and vertical coordinates corresponding to the first metasurface plane 10.

[0106] As an example, refer again Figure 2 The phase distribution corresponding to the incident electric field distribution of the first metasurface plane 10 is specifically defined as follows:

[0107]

[0108] x1∈[-L1 / 2,L1 / 2],y1∈[-L1 / 2,L1 / 2]

[0109] Where L1 can be 200 mm, which is the side length of the first metasurface plane 10; x1 is the abscissa value on the two-dimensional coordinate system established at the center of the first metasurface plane 10; and y1 is the ordinate value on the two-dimensional coordinate system established at the center of the first metasurface plane 10. The incident electric field phase value is the horizontal and vertical coordinates corresponding to the first metasurface plane 10.

[0110] S3. Based on the incident electric field distribution of the first metasurface plane 10 and the amplitude distribution required by the target sidelobe, the outgoing electric field distribution of the first metasurface plane 10 is obtained using the particle swarm optimization algorithm.

[0111] As a demonstration site, for reference Figure 6 The phase corresponding to the emitted electric field distribution of the first metasurface plane 10 is defined as:

[0112]

[0113] x1∈[-L1 / 2,L1 / 2],y1∈[-L1 / 2,L1 / 2]

[0114] Where L1 can be 200 mm, which is the side length of the first metasurface plane 10; x1 is the abscissa value on the two-dimensional coordinate system established at the center of the first metasurface plane 10; and y1 is the ordinate value on the two-dimensional coordinate system established at the center of the first metasurface plane 10. The phase value of the emitted electric field corresponding to the horizontal and vertical coordinates of the first metasurface plane 10;

[0115] The amplitude distribution corresponding to the emitted electric field distribution of the first metasurface plane 10 is specifically defined as follows:

[0116]

[0117] x1∈[-L1 / 2,L1 / 2],y1∈[-L1 / 2,L1 / 2]

[0118] Where L1 can be 200 mm, which is the side length of the first metasurface plane 10; x1 is the abscissa value on the two-dimensional coordinate system established at the center of the first metasurface plane 10; and y1 is the ordinate value on the two-dimensional coordinate system established at the center of the first metasurface plane 10. The amplitude of the emitted electric field is the horizontal and vertical coordinates corresponding to the first metasurface plane 10.

[0119] The particle swarm optimization algorithm is well-known to those skilled in the art, and its process can be found by referring to [reference needed]. Figure 4 .

[0120] Specifically, obtaining the emitted electric field distribution of the first metasurface plane 10 based on the particle swarm optimization algorithm includes:

[0121] The phase distribution corresponding to the emitted electric field distribution of the first metasurface plane 10 in the initial region is initialized;

[0122] The phase distribution is extended to all regions of the first metasurface plane 10 by mirroring to form the output electric field phase distribution of the first metasurface plane 10.

[0123] The phase distribution of the emitted electric field of the first metasurface plane 10 is combined with the amplitude distribution of the emitted electric field of the first metasurface plane 10 to form the emitted electric field distribution of the first metasurface plane 10, wherein the amplitude distribution of the emitted electric field of the first metasurface plane 10 is the same as the amplitude distribution of the incident electric field of the first metasurface plane 10.

[0124] As an example, the initialization area can be a quarter or any other range set according to actual needs.

[0125] The above mirror extensions can be referenced. Figure 5 The form it represents.

[0126] The sidelobe grade of the target sidelobe can be selected or customized according to the user's actual needs.

[0127] The amplitude distribution required for the target sidelobe can be the Chebyshev amplitude distribution, Taylor amplitude distribution, etc., which are well known to those skilled in the art. However, for the sake of convenience, this article will use the Chebyshev amplitude distribution as an example.

[0128] Please refer to Figure 2 The Chebyshev amplitude distribution is defined as:

[0129] |E 切比雪夫(x2,y2)|

[0130] x2∈[-L2 / 2,L2 / 2],y2∈[-L2 / 2,L2 / 2]

[0131] Where L2 can be 200 mm, representing the side length of the second metasurface plane 20; x2 is the abscissa value in the two-dimensional coordinate system established at the center of the second metasurface plane 20; y2 is the ordinate value in the two-dimensional coordinate system established at the center of the second metasurface plane 20; |E 切比雪夫 (x2,y2)| represents the Chebyshev electric field amplitude corresponding to the horizontal and vertical coordinates on the second metasurface plane 20;

[0132] S4. Based on the emitted electric field distribution and the incident electric field distribution of the first metasurface plane 10, the incident electric field distribution of the second metasurface plane 20 is obtained using a physical optical electromagnetic algorithm.

[0133] As an example, refer to Figure 7 On the left side, the amplitude distribution corresponding to the incident electric field distribution of the second metasurface plane 20 is defined as follows:

[0134]

[0135] x2∈[-L2 / 2,L2 / 2],y2∈[-L2 / 2,L2 / 2]

[0136] Where L2 can be 200 mm, which is the side length of the second metasurface plane 20; x2 is the abscissa value on the two-dimensional coordinate system established at the center of the second metasurface plane 20; and y2 is the ordinate value on the two-dimensional coordinate system established at the center of the second metasurface plane 20. The electric field values ​​corresponding to the horizontal and vertical coordinates on the second metasurface plane 20 are given.

[0137] As an example, refer again Figure 7 The phase distribution corresponding to the incident electric field distribution on the right side of the second metasurface plane 20 is defined as follows:

[0138]

[0139] x2∈[-L2 / 2,L2 / 2],y2∈[-L2 / 2,L2 / 2]

[0140] Where L2 can be 200 mm, which is the side length of the second metasurface plane 20; x2 is the abscissa value on the two-dimensional coordinate system established at the center of the second metasurface plane 20; and y2 is the ordinate value on the two-dimensional coordinate system established at the center of the second metasurface plane 20. The electric field phase on the second metasurface plane 20 corresponding to the horizontal and vertical coordinates.

[0141] To improve the accuracy of the incident electric field distribution of the second metasurface plane 20, the following steps are included before obtaining the incident electric field distribution of the second metasurface plane 20:

[0142] The output electric field distribution of the first metasurface plane 10 is optimized.

[0143] Here, common forms of optimization processing can be demonstrated. Optimization processing specifically includes:

[0144] The incident electric field amplitude distribution and Chebyshev amplitude distribution of the second metasurface plane 20, obtained from the current value of the emitted electric field distribution of the first metasurface plane 10, are evaluated using a preset fitness function, and the current value is updated.

[0145] Iterate over the current value to obtain the optimized output electric field distribution of the first metasurface plane 10.

[0146] The fitness function is defined as follows:

[0147]

[0148] x2∈[-L2 / 2,L2 / 2],y2∈[-L2 / 2,L2 / 2]

[0149] Where L2 can be 200 mm, which is the side length of the second metasurface plane 20, x2 is the abscissa value on the two-dimensional coordinate system established at the center of the second metasurface plane 20, and y2 is the ordinate value on the two-dimensional coordinate system established at the center of the second metasurface plane 20.

[0150] S5. Based on the phase distribution required for the target aperture efficiency, adjust the incident electric field distribution of the second metasurface plane 20 to obtain the output electric field distribution of the second metasurface plane 20.

[0151] Specifically, the distribution of the incident electric field on the second metasurface plane 20 is controlled as follows:

[0152] Adjust the incident electric field distribution corresponding to the phase distribution of the second metasurface plane 20 until the phase distribution is a preset constant.

[0153] Here, the default constant is generally assumed to be 0.

[0154] S6. The phase distribution corresponding to the incident electric field distribution of the first metasurface plane 10 and the phase distribution corresponding to the outgoing electric field distribution of the first metasurface plane 20 are determined as the first target control phase for the first metasurface plane 10.

[0155] Refer again Figure 6 The first target modulation phase is defined as

[0156]

[0157] x1∈[-L1 / 2,L1 / 2],y1∈[-L1 / 2,L1 / 2]

[0158] Where L1 can be 200 mm, representing the side length of the first metasurface plane 10; x1 is the abscissa value in the two-dimensional coordinate system established at the center of the first metasurface plane 10; y1 is the ordinate value in the two-dimensional coordinate system established at the center of the first metasurface plane 10; and φ... S1 (x1, y1) represents the modulated phase of the horizontal and vertical coordinates corresponding to the first metasurface plane 10.

[0159] S7. Determine the phase distribution corresponding to the incident electric field distribution of the second metasurface plane 20 as the second target control phase for the second metasurface plane 20.

[0160] Refer again Figure 7 The second target regulation phase is defined as

[0161]

[0162] x2∈[-L2 / 2,L2 / 2],y2∈[-L2 / 2,L2 / 2]

[0163] Where L2 can be 200 mm, representing the side length of the second metasurface plane 20; x2 is the abscissa value in the two-dimensional coordinate system established at the center of the second metasurface plane 20; y2 is the ordinate value in the two-dimensional coordinate system established at the center of the second metasurface plane 20; and φ... S2 (x2, y2) represents the phase adjustment of the horizontal and vertical coordinates corresponding to the second metasurface plane 20.

[0164] It is worth noting that the metasurface modulation method of the transmission array antenna in this application mainly involves designing the modulation phases of two electromagnetic metasurface planes, namely the first metasurface plane 10 and the second metasurface plane 20. The first metasurface plane 10 achieves the Chebyshev amplitude distribution corresponding to low sidelobes at the second metasurface plane 20 through phase modulation. The second metasurface plane 20 achieves a high-aperture-efficiency (high-gain) antenna beam through phase modulation. The amplitude is not changed during the phase modulation process, that is, the incident and emitted electric field amplitudes of the first metasurface plane 10 are equal, and the incident and emitted electric field amplitudes of the second metasurface plane 20 are equal. The modulation phases of the first metasurface plane 10 and the second metasurface plane 20 are determined by the incident and emitted electric field phases of the two planes, respectively.

[0165] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A metasurface manipulation method for a transmission array antenna, characterized in that, include: The first metasurface plane and the second metasurface plane are arranged sequentially from near to far along the radiation path of the antenna's horn feed. Obtain the incident electric field distribution radiated from the horn feed source onto the first metasurface plane; Based on the incident electric field distribution of the first metasurface plane and the amplitude distribution required by the target sidelobe, the output electric field distribution of the first metasurface plane is obtained using a particle swarm optimization algorithm, including: The phase distribution corresponds to the emitted electric field distribution of the first metasurface plane in the initial region; The phase distribution is extended to all regions of the first metasurface plane by mirroring to form the phase distribution of the emitted electric field of the first metasurface plane; The phase distribution of the emitted electric field of the first metasurface plane and the amplitude distribution of the emitted electric field of the first metasurface plane are combined to form the emitted electric field distribution of the first metasurface plane, wherein the amplitude distribution of the emitted electric field of the first metasurface plane is the same as the amplitude distribution of the incident electric field of the first metasurface plane. The phase corresponding to the emitted electric field distribution on the first metasurface plane is defined as follows: in Let be the side length of the first metasurface plane. The x-coordinate value in the two-dimensional coordinate system established for the center of the first metasurface plane. The ordinate value in the two-dimensional coordinate system established with the center of the first metasurface plane. The phase value of the emitted electric field corresponding to the horizontal and vertical coordinates of the first metasurface plane; The amplitude distribution corresponding to the emitted electric field distribution on the first metasurface plane is specifically defined as follows: in Let be the side length of the first metasurface plane. The x-coordinate value in the two-dimensional coordinate system established for the center of the first metasurface plane. The ordinate value in the two-dimensional coordinate system established with the center of the first metasurface plane. The output electric field amplitude is the horizontal and vertical coordinates corresponding to the first metasurface plane; based on the output electric field distribution and the incident electric field distribution of the first metasurface plane, the incident electric field distribution of the second metasurface plane is obtained using a physical optical electromagnetic algorithm. Based on the phase distribution required for the target aperture efficiency, the incident electric field distribution of the second metasurface plane is adjusted to obtain the output electric field distribution of the second metasurface plane; The phase distribution corresponding to the incident electric field distribution of the first metasurface plane and the phase distribution corresponding to the outgoing electric field distribution of the first metasurface plane are determined as the first target control phase for the first metasurface plane; The phase distribution corresponding to the incident electric field distribution of the second metasurface plane is determined as the second target control phase for the second metasurface plane.

2. The method for controlling the metasurface of the transmission array antenna according to claim 1, characterized in that, The incident electric field distribution of the first metasurface plane was obtained through simulation using the full-wave electromagnetic simulation software CST.

3. The method for controlling the metasurface of the transmission array antenna according to claim 1, characterized in that, The steps preceding the process of obtaining the incident electric field distribution on the second metasurface plane also include: The output electric field distribution of the first metasurface plane is optimized.

4. The method for controlling the metasurface of the transmission array antenna according to claim 3, characterized in that, The optimization process specifically includes: The incident electric field amplitude distribution and Chebyshev amplitude distribution of the second metasurface plane, obtained from the current value of the emitted electric field distribution of the first metasurface plane, are evaluated using a preset fitness function, and the current value is updated. The amplitude distribution required for the target sidelobe is defined as follows: in Let be the side length of the second metasurface plane. The x-coordinate value in a two-dimensional coordinate system established with the center of the second metasurface plane. The ordinate value in the two-dimensional coordinate system established with the center of the second metasurface plane. Let be the Chebyshev electric field amplitude corresponding to the horizontal and vertical coordinates on the second metasurface plane; The amplitude distribution corresponding to the incident electric field distribution of the second metasurface plane is defined as follows: in Let be the side length of the second metasurface plane. The x-coordinate value in a two-dimensional coordinate system established with the center of the second metasurface plane. The ordinate value in the two-dimensional coordinate system established with the center of the second metasurface plane. The electric field values ​​corresponding to the horizontal and vertical coordinates on the second metasurface plane; The fitness function is defined as: in Let be the side length of the second metasurface plane. The x-coordinate value in a two-dimensional coordinate system established with the center of the second metasurface plane. The ordinate value in a two-dimensional coordinate system established for the center of the second metasurface plane; Iterate over the current value to obtain the optimized output electric field distribution of the first metasurface plane.

5. The method for controlling the metasurface of the transmission array antenna according to claim 1, characterized in that, The distribution of the incident electric field on the second metasurface plane is controlled as follows: The phase distribution corresponding to the incident electric field distribution on the second metasurface plane is adjusted until the phase distribution is a preset constant.

6. The method for controlling the metasurface of the transmission array antenna according to claim 1, characterized in that, The phase distribution corresponding to the incident electric field distribution on the second metasurface plane is defined as follows: in Let be the side length of the second metasurface plane. The x-coordinate value in a two-dimensional coordinate system established with the center of the second metasurface plane. The ordinate value in the two-dimensional coordinate system established with the center of the second metasurface plane. The electric field phase on the second metasurface plane corresponding to the horizontal and vertical coordinates is denoted as .

7. The method for controlling the metasurface of the transmission array antenna according to claim 1, characterized in that, The first target modulation phase is defined as in Let be the side length of the first metasurface plane. The x-coordinate value in the two-dimensional coordinate system established for the center of the first metasurface plane. The ordinate value in the two-dimensional coordinate system established with the center of the first metasurface plane. The phase of the first metasurface plane corresponding to the horizontal and vertical coordinates is the control phase. The second target regulation phase is defined as in Let be the side length of the second metasurface plane. The x-coordinate value in a two-dimensional coordinate system established with the center of the second metasurface plane. The ordinate value in the two-dimensional coordinate system established with the center of the second metasurface plane. This refers to the phase adjustment of the horizontal and vertical coordinates corresponding to the second metasurface plane.

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