Low-orbit satellite common-aperture antenna feed device and low-orbit satellite common-aperture antenna feed method

Abstract

The invention discloses a low-orbit satellite common-aperture antenna feed device and method, and the device comprises a metasurface structure and a control unit, and the metasurface structure is electrically connected with the control unit. Wherein the metasurface structure comprises a plurality of units, each unit comprises a metal patch layer and an adjustable dielectric layer, and the metal patch layer has a preset geometrical shape; and the control unit is used for dynamically changing the electromagnetic response of the metasurface structure by adjusting the electromagnetic parameters of the adjustable dielectric layer so as to realize independent transceiving and beam control of multi-band signals. Therefore, according to the embodiment of the invention, the antenna is more suitable for high-frequency band application due to the low-profile design of the metasurface structure, and the high processing precision requirement caused by a complex three-dimensional structure is avoided. And meanwhile, the metal patch layer has a preset geometrical shape, and resonance characteristics of different frequency bands can be independently regulated and controlled, so that the flexibility and adaptability of the antenna system are remarkably improved, and the requirement for multi-frequency-band compatibility in satellite communication is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of millimeter wave / terahertz communication, in particular to a low-orbit satellite common-aperture antenna feeding device and method. BACKGROUND

[0002] With the development of satellite communication to higher frequency bands, the requirements for antenna systems are increasingly high. Not only is it necessary to support multi-band operation to adapt to abundant spectrum resources, but it is also necessary to have flexible beam control capabilities to achieve precise spatial signal coverage.

[0003] In order to meet the multi-band requirements of satellite communication for antennas, millimeter wave low frequency band designs based on PIN diodes or complex feeding networks are currently used. However, designs based on PIN diodes or complex feeding networks are difficult to be practical at high frequency bands (such as Q / V frequency bands and above) due to the sharp increase in diode parasitic effects and transmission line losses. While existing terahertz frequency band designs can work at high frequency bands, their resonant structures are mostly very complex, requiring the stacking of multiple layers of structures or the use of complex anisotropic units, which have very high processing precision requirements and are not conducive to the low-cost preparation and integration of large-scale arrays. In addition, existing technologies achieve dual-frequency operation through the same polarization structure, but the control of the two frequency points is often coupled, that is, when the parameters of one frequency point are changed, the performance of the other frequency point will also be significantly affected, which cannot meet the independent control requirements of multi-band in satellite communication. SUMMARY

[0004] The embodiments of the present application provide a low-orbit satellite common-aperture antenna feeding device. In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This part is not a general review, nor is it intended to determine the key / important constituent elements or delineate the protection scope of these embodiments. Its only purpose is to present some concepts in a simple form as a prelude to the detailed description that follows.

[0005] In a first aspect, the embodiments of the present application provide a low-orbit satellite common-aperture antenna feeding device, the device comprising: a metasurface structure and a control unit, the metasurface structure being electrically connected to the control unit; wherein the metasurface structure comprises a plurality of units, each unit comprising a metal patch layer and an adjustable dielectric layer, the metal patch layer having a preset geometric shape; the control unit is configured to dynamically change the electromagnetic response of the metasurface structure by adjusting the electromagnetic parameters of the adjustable dielectric layer, so as to realize independent transmission and reception of multi-band signals and beam control.

[0006] Optionally, the preset geometric shape is a diamond symmetric structure, and a cross-shaped slot is introduced at the center of the diamond structure; wherein The metal patch layer is used for respectively regulating the X-direction and Y-direction resonance characteristics through the geometric parameters of the cross-shaped slot when electromagnetic waves are incident on the metasurface structure.

[0007] Optionally, the cross-shaped slot includes an X-direction slot and a Y-direction slot, the X-direction slot and the Y-direction slot are perpendicular to each other, and the length and width of the X-direction slot and the Y-direction slot can be independently adjusted in different production demand scenarios. The X-direction slot is used for optimizing the resonance characteristics of a frequency band 1. The Y-direction slot is used for optimizing the resonance characteristics of a frequency band 2, and the frequency band 1 is different from the frequency band 2.

[0008] Optionally, the electromagnetic response of the metasurface structure is dynamically changed by adjusting the electromagnetic parameters of the adjustable dielectric layer, including: Applying a control signal to the metasurface structure to change the electromagnetic parameters of the adjustable dielectric layer; Adjusting the reflection phase of the X-polarized incident wave in the frequency band 1; Or adjusting the reflection phase of the Y-polarized incident wave in the frequency band 2.

[0009] Optionally, the frequency band 1 and the frequency band 2 can each select a corresponding electromagnetic parameter combination with a phase difference of 180°, which is mapped to 0 and 1 states in the digital domain, to meet the dual-band 1-bit phase regulation requirement.

[0010] Optionally, the metasurface structure includes a plurality of units arranged in a two-dimensional array according to a preset arrangement mode, and the two-dimensional array arranges 0 and 1 units through a digital coding mode.

[0011] Optionally, each unit is a five-layer stacked structure, and the five-layer stacked structure includes, from top to bottom, a quartz glass layer, a metal patch layer, an adjustable dielectric layer, a metal ground layer, and a quartz glass substrate. The unit size of each unit is a sub-wavelength scale.

[0012] Optionally, the control unit includes a bias circuit connected to the metal patch layer and the metal ground layer. The bias circuit is used for applying a control signal between the metal patch layer and the metal ground layer through a bias line to form an electric field in the adjustable dielectric layer, so as to regulate the electromagnetic parameters of the adjustable dielectric layer.

[0013] In a second aspect, a low-orbit satellite common-aperture antenna feeding method includes: In response to a communication task instruction, analyzing task requirements to determine a target frequency band and a beam pointing direction; Based on the target frequency band and the beam pointing direction, calculating and matching the X-direction and Y-direction resonance parameters by using the geometric characteristics of the metal patch layer to determine the phase characteristics that each unit in the metasurface structure should have. According to the phase characteristics and phase distribution requirements to be met, a dynamic bias voltage is applied to the adjustable dielectric layer to adjust the electromagnetic parameters of the adjustable dielectric layer, so as to change the electromagnetic response of the metasurface structure and realize independent transmission and reception of multi-band signals and beam control.

[0014] Optionally, adjusting the electromagnetic parameters of the adjustable dielectric layer to change the electromagnetic response of the metasurface structure comprises: applying a control signal to the metasurface structure to change the electromagnetic parameters of the adjustable dielectric layer; when in frequency band 1, adjusting the reflection phase for X-polarized incident waves; or when in frequency band 2, adjusting the reflection phase for Y-polarized incident waves.

[0015] In the embodiments of the present application, on the one hand, the low profile design of the metasurface structure makes the antenna more suitable for high frequency band applications, avoiding the high machining precision requirement brought by complex three-dimensional structures. At the same time, the metal patch layer has a preset geometric shape, which can independently adjust and control the resonant characteristics of different frequency bands, thereby significantly improving the flexibility and adaptability of the antenna system and meeting the requirements of multi-band compatibility in satellite communication. On the other hand, the preset geometric shape is a rhombus symmetric structure, a cross-shaped slot is introduced in the center of the rhombus structure, and the X-direction and Y-direction resonant characteristics can be adjusted and controlled through the size of the cross-shaped slot in the center, which adapts to the needs of satellite-ground communication; at two operating frequency points, a wide range of phase change of >180° can be realized, supporting a 1bit beam scanning function, and meeting the practical requirements of satellite communication.

[0016] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the specification, serve to explain the principles of the present application.

[0018] Figure 1 is a device structure schematic diagram of a low-orbit satellite common-aperture antenna feeding device provided by an embodiment of the present application; Figure 2 is an array structure schematic diagram of a metasurface structure provided by an embodiment of the present application; Figure 3 is a top view of a unit structure provided by an embodiment of the present application; Figure 4 is a side view of a unit structure provided by an embodiment of the present application; Figure 5 is a curve graph of amplitude change before slotting provided by an embodiment of the present application; Figure 6is a phase shift change curve diagram before slotting provided by an embodiment of the present application; Figure 7 is an amplitude change curve diagram after slotting provided by an embodiment of the present application; Figure 8 is a phase shift change curve diagram after slotting provided by an embodiment of the present application; Figure 9 is a flowchart of a low-orbit satellite common-aperture antenna feeding method provided by an embodiment of the present application. DETAILED DESCRIPTION

[0019] The following description and drawings are illustrative of the specific embodiments of the present application and are not intended to limit the generality of the application.

[0020] It should be noted that the described embodiments are merely a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0021] In the following description, when the description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments are not meant to represent all implementations consistent with the present application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the present application as detailed in the appended claims.

[0022] In the description of the present application, it should be understood that the terms "first", "second", etc. are used only for the purpose of description, and cannot be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, unless otherwise specified, "multiple" means two or more. "And / or", which describes the relationship between the associated objects, means that there can be three relationships, for example, A and / or B can mean that there are three cases of A alone, A and B together, and B alone. The character " / " generally represents that the associated objects before and after are in an "or" relationship.

[0023] In the embodiments of the present application, on the one hand, the low profile design of the metasurface structure makes the antenna more suitable for high frequency applications, avoiding the high machining precision requirement brought by complex three-dimensional structures. At the same time, the metal patch layer has a preset geometric shape, which can independently control the resonant characteristics of different frequency bands, thereby significantly improving the flexibility and adaptability of the antenna system, meeting the requirements of multi-band compatibility in satellite communication. On the other hand, the preset geometric shape is a rhombic symmetric structure, and a cross-shaped slot is introduced in the center of the rhombic structure. The X and Y direction resonant characteristics can be controlled respectively through the size of the cross-shaped slot in the center, which adapts to the needs of satellite-ground communication; at two operating frequencies, a wide range of phase change of >180° can be achieved, supporting 1bit beam scanning function, meeting the practical requirements of satellite communication. The following will be described in detail by exemplary embodiments.

[0024] Please refer to Figure 1 , Figure 1 is a device structure schematic diagram of a low-orbit satellite common-aperture antenna feeding device provided by the embodiments of the present application. The device comprises a metasurface structure, a control unit, and the metasurface structure is electrically connected with the control unit; wherein the metasurface structure comprises a plurality of units, each unit comprises a metal patch layer and an adjustable dielectric layer, and the metal patch layer has a preset geometric shape; the control unit is used to dynamically change the electromagnetic response of the metasurface structure by adjusting the electromagnetic parameters of the adjustable dielectric layer, so as to realize independent transmission and reception of multi-band signals and beam control.

[0025] Preferably, the adjustable dielectric layer is preferably a liquid crystal antenna. The electromagnetic parameters include dielectric constant, magnetic permeability, dielectric height, etc.

[0026] In some embodiments of the present application, each unit is a five-layer stacked structure, and the five-layer stacked structure comprises, from top to bottom, a quartz glass layer, a metal patch layer, an adjustable dielectric layer, a metal ground layer and a quartz glass substrate; the unit size of each unit is a subwavelength scale; the metal patch layer has the functions of radiator and direct current bias positive electrode, and the metal ground layer is a bias negative electrode.

[0027] In some embodiments of the present application, the plurality of units of the metasurface structure are arranged in a two-dimensional array according to a preset arrangement mode, and the two-dimensional array is arranged by digital coding mode 0 and 1 units. The metasurface structure is shown in FIG. 32×32 array can be adjusted to 16×16 or 40×40 scale according to actual application requirements, the core is to realize directional beamforming to support satellite communication beam tracking. Figure 2

[0028] ​Metamaterials, as artificial composite structures or materials, can achieve unprecedented control over electromagnetic waves through the careful design of their subwavelength unit structures, such as negative refraction and electromagnetic cloaking. However, three-dimensional bulk metamaterials face inherent challenges, including complex structures, high ohmic losses, and difficulties in integration and fabrication. Metasurfaces, as the two-dimensional counterpart of metamaterials, can achieve flexible manipulation of key properties of electromagnetic waves, such as amplitude, phase, and polarization, with lower profiles and losses, by arranging single-layer or a few-layer subwavelength atomic structures in a specific order on a plane. This opens up new avenues for the development of planarized and integrated photonic / electromagnetic devices.

[0029] A significant advancement building upon this foundation is the introduction of the concepts of digitally coded metasurfaces and programmable metasurfaces. This technological paradigm discretizes the different electromagnetic response states of each unit of a metasurface into a finite set of digital codes (e.g., "0" and "1" represent reflection phases of 0° and 180°, respectively), thereby abstracting the physical metasurface into a digital information interface. By integrating active control elements (such as diodes, liquid crystals, and MEMS) and applying external stimuli (such as bias voltage), real-time and dynamic reconstruction of the coded states of the metasurface can be achieved. Combined with control circuits such as field-programmable gate arrays (FPGAs), programmable metasurfaces can realize various functions such as dynamic beam scanning, radar cross section (RCS) reduction, and holographic imaging, providing a revolutionary hardware platform for next-generation wireless communication, radar sensing, and imaging systems.

[0030] Satellite communication services are evolving towards multi-band convergence (such as Ku, Ka, Q / V, and even terahertz bands) to support higher data transmission rates and capacities. Configuring a separate antenna system for each band would drastically increase the size, weight, cost, and complexity of the terminal. Therefore, multi-band co-aperture antenna technology has emerged, with its core objective being to achieve independent transmission and reception of multiple frequency bands and beam control within the same physical aperture.

[0031] Among the many technological approaches to realizing programmable metasurfaces, liquid crystal-based modulation schemes exhibit unique advantages in the millimeter-wave to terahertz frequency band. Liquid crystal materials possess dielectric anisotropy, and their effective electromagnetic parameters can be continuously adjusted by an external electric field, thereby altering the electromagnetic response of the integrated liquid crystal metasurface unit. Compared to semiconductor diodes (such as PIN diodes and varactor diodes), liquid crystals offer relatively lower losses and lower costs at higher frequencies, making them easier to integrate and deploy in large-scale arrays.

[0032] Specifically, the quartz glass layer serves as a protective layer, providing mechanical support and electrical insulation. The metal patch layer functions as both a radiator and a DC bias positive electrode. This layer uses a specific geometry (such as a rhomboid patch) to achieve the radiation and modulation of electromagnetic waves. The tunable dielectric layer adjusts electromagnetic parameters by applying an external electric field, thereby changing the phase and amplitude of the electromagnetic waves. The metal ground layer acts as a bias negative electrode, providing a reference plane for the electric field. The quartz glass substrate provides mechanical support and electrical insulation.

[0033] Specifically, the main function of the control unit is to apply an external electric field to the tunable dielectric layer through a bias circuit, thereby adjusting the electromagnetic parameters of the tunable dielectric layer.

[0034] In some embodiments of this application, the preset geometry is a rhomboid symmetrical structure, and a cross-shaped slot is introduced at the center of the rhomboid structure; wherein, the metal patch layer is used to adjust the X-direction and Y-direction resonance characteristics respectively by means of the geometric parameters of the cross-shaped slot when electromagnetic waves are incident on the metasurface structure.

[0035] In some embodiments of this application, the cross-shaped slot includes an X-direction slot and a Y-direction slot, which are perpendicular to each other. The length and width of the X-direction slot and the Y-direction slot can be independently adjusted under different production requirements. The X-direction slot is used to optimize the resonant characteristics of frequency band 1, and the Y-direction slot is used to optimize the resonant characteristics of frequency band 2. Frequency band 1 and frequency band 2 are not the same. For example, frequency band 1 is a 170GHz band, and frequency band 2 is a 220GHz band.

[0036] Specifically, the metal patch layer adopts a rhombus structure. A key improvement is the introduction of a cross-shaped slot at the center of the rhombus patch layer. This slot is divided into X-axis and Y-axis slots, which are perpendicular to each other and whose length and width are independently adjustable. Based on optimizing the basic rhombus patch dimensions, the cross-slot parameters are finely adjusted, making the resonant frequency design more controllable and expanding the phase shift range. A top view of the rhombus patch with the cross-slot is shown below. Figure 3 As shown, it includes a cross-shaped slot 1 with X-direction and Y-direction slots, a rhombus structure 2, and a side view of the rhombus patch with the cross-shaped slot, for example... Figure 4 As shown.

[0037] It should be noted that the tunable dielectric layer can be replaced with other electrically tunable materials (such as ferroelectric materials) to achieve similar functionality. The rhombus shape can be replaced with chamfered rectangles, circles, etc., combined with a central slot structure to achieve responses under different polarization modes. The cross-shaped slot can be replaced with T-shaped, V-shaped, H-shaped, and other combinations to achieve similar multi-frequency resonance control. The cross-shaped slot can be finely adjusted in the central region of the rhombus patch; as long as the resonance matching and phase shift characteristics are not compromised, these are all equivalent alternatives. For example... Figure 5 As shown, before slotting, the S11 amplitude was 220G with no obvious resonance, and the low-frequency resonance was around 185G. For example...Figure 6 As shown, before slotting, the S11 phase shift is as follows: Y-polarization has no phase shift, while the X-polarization phase shift function is achieved around 185G. For example... Figure 7 As shown, after slotting, the amplitude of S11 shows significant resonance near both operating frequencies. For example... Figure 8 As shown, after slotting, the S11 phase shift is significant: the X / Y polarizations are significantly shifted at the required operating frequencies.

[0038] Specifically, based on liquid crystal material as the dielectric layer, the performance indicators of different X and Y lengths of cross-shaped slots are shown in Table 1 (other parameter values ​​are the same as in Table 2).

[0039] Table 1

[0040] In some embodiments of this application, the specific process of dynamically changing the electromagnetic response of a metasurface structure by adjusting the electromagnetic parameters of the tunable dielectric layer includes: applying a control signal to the metasurface structure to change the electromagnetic parameters of the tunable dielectric layer; adjusting the reflection phase for X-polarized incident waves at frequency band 1; or adjusting the reflection phase for Y-polarized incident waves at frequency band 2.

[0041] The control signal can be a voltage, current, or optical signal, depending on the choice of dielectric layer material.

[0042] In particular, both frequency band 1 and frequency band 2 can select corresponding electromagnetic parameter combinations with a phase difference of 180°, which are mapped to 0 and 1 states in the digital domain to meet the dual-band 1-bit phase control requirements.

[0043] In some embodiments of this application, the control unit includes a bias circuit connected to a metal patch layer and a metal ground layer; the bias circuit is used to apply a control signal between the metal patch layer and the metal ground layer through a bias line to form an electric field in the tunable dielectric layer, so as to realize the regulation of the electromagnetic parameters of the tunable dielectric layer.

[0044] Specifically, the unit structure parameter table of each unit in the metasurface structure of the embodiment is shown in Table 2.

[0045] Table 2

[0046] Specifically, based on array antenna theory and combined with Snell's law, for periodic coding, the spatial beam pointing angle (θ, φ) of the reflected wave can be calculated using the following formula:

[0047]

[0048] in, Refers to the operating wavelength. , The phase gradient coding period refers to the period along the X and Y axes. The pitch angle is the angle between the reflected beam and the normal to the metasurface. The azimuth angle is used. Dual-band beam scanning is achieved by dynamically adjusting the phase distribution coding period of the array. Simulation results verify that beam scanning capability is available in both the 170GHz and 220GHz bands.

[0049] In this embodiment, on the one hand, the low-profile design of the metasurface structure makes the antenna more suitable for high-frequency applications, avoiding the high processing precision requirements of complex three-dimensional structures. Simultaneously, the metal patch layer has a preset geometry, allowing independent adjustment of the resonant characteristics of different frequency bands, thus significantly improving the flexibility and adaptability of the antenna system and meeting the multi-band compatibility requirements of satellite communication. On the other hand, the preset geometry is a rhomboid symmetrical structure with a cross-shaped slot at the center. The size of the central cross-shaped slot allows for separate adjustment of the X-axis and Y-axis resonant characteristics, adapting to the needs of satellite-to-ground communication. At both operating frequencies, a wide-range phase change of >180° can be achieved, supporting 1-bit beam scanning, meeting the practical requirements of satellite communication.

[0050] Please see Figure 9 This document provides a flowchart illustrating a common-aperture antenna feeding method for low-orbit satellites, applicable to a control unit. (See attached diagram.) Figure 9 As shown, the detection method in this application embodiment may include the following steps: S101, in response to the communication task command, parses the task requirements to determine the target frequency band and beam direction; S102, based on the target frequency band and beam direction, determine the phase characteristics that each unit in the metasurface structure should possess; S103, according to the required phase characteristics and phase distribution, applies a dynamic bias voltage to the tunable dielectric layer through a bias circuit to adjust the electromagnetic parameters of the tunable dielectric layer, thereby changing the electromagnetic response of the metasurface structure and realizing independent transmission and reception of multi-band signals and beam control.

[0051] In some embodiments of this application, the specific process of adjusting the electromagnetic parameters of the tunable dielectric layer to change the electromagnetic response of the metasurface structure includes: applying a control signal to the metasurface structure to change the electromagnetic parameters of the tunable dielectric layer; adjusting the reflection phase for X-polarized incident waves at frequency band 1; or adjusting the reflection phase for Y-polarized incident waves at frequency band 2.

[0052] In one possible implementation, the control unit activates and applies an initial electric field to the tunable dielectric layer in the metasurface structure via a bias circuit. Liquid crystal molecules align under the initial electric field, forming an initial electromagnetic parameter distribution. The control unit generates control signals via a digital control circuit based on a preset beam control algorithm or external commands. These control signals are transmitted to each cell in the metasurface structure through an interface circuit, adjusting the bias voltage of each cell. Changes in the bias voltage alter the electromagnetic parameters of the tunable dielectric layer, thereby changing the electromagnetic response (e.g., phase and amplitude) of each cell. By dynamically adjusting the phase state of each cell in the metasurface array, the control unit achieves beam direction variation. For example, in a 32×32 array, the control unit can generate specific phase gradient codes to direct the beam in the desired direction.

[0053] In this embodiment, on the one hand, the low-profile design of the metasurface structure makes the antenna more suitable for high-frequency applications, avoiding the high processing precision requirements of complex three-dimensional structures. Simultaneously, the metal patch layer has a preset geometry, allowing independent adjustment of the resonant characteristics of different frequency bands, thus significantly improving the flexibility and adaptability of the antenna system and meeting the multi-band compatibility requirements of satellite communication. On the other hand, the preset geometry is a rhomboid symmetrical structure with a cross-shaped slot at the center. The size of the central cross-shaped slot allows for separate adjustment of the X-axis and Y-axis resonant characteristics, adapting to the needs of satellite-to-ground communication. At both operating frequencies, a wide-range phase change of >180° can be achieved, supporting 1-bit beam scanning, meeting the practical requirements of satellite communication.

[0054] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program for feeding a common-aperture antenna for low-Earth orbit satellites can be stored in a computer-readable storage medium. When executed, the program can include the processes of the embodiments of the above methods. The storage medium for the program for feeding a common-aperture antenna for low-Earth orbit satellites can be a magnetic disk, optical disk, read-only memory, or random access memory, etc.

[0055] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application shall still fall within the scope of this application.

Claims

1. A low-orbit satellite common-aperture antenna feeding device, characterized in that, The device includes: A metasurface structure and a control unit, wherein the metasurface structure and the control unit are electrically connected; wherein... The metasurface structure comprises multiple units, each unit comprising a metal patch layer and an adjustable dielectric layer, wherein the metal patch layer has a preset geometry. The control unit is used to dynamically change the electromagnetic response of the metasurface structure by adjusting the electromagnetic parameters of the tunable dielectric layer, so as to realize independent transmission and reception of multi-band signals and beam control.

2. The low-orbit satellite common-aperture antenna feeding device according to claim 1, characterized in that, The preset geometric shape is a rhomboid symmetrical structure, and a cross-shaped slot is introduced at the center of the rhomboid structure; wherein... The metal patch layer is used to adjust the X-axis and Y-axis resonance characteristics respectively by means of the geometric parameters of the cross-shaped slot when electromagnetic waves are incident on the metasurface structure.

3. The low-orbit satellite common-aperture antenna feeding device according to claim 2, characterized in that, The cross-shaped slot includes an X-axis slot and a Y-axis slot, which are perpendicular to each other. The length and width of the X-axis slot and the Y-axis slot can be independently adjusted under different production requirements. The X-direction slot is used to optimize the resonance characteristics of frequency band 1; The Y-direction slot is used to optimize the resonance characteristics of frequency band 2, and frequency band 1 is different from frequency band 2.

4. The low-orbit satellite common-aperture antenna feeding device according to claim 2, characterized in that, The method of dynamically changing the electromagnetic response of the metasurface structure by adjusting the electromagnetic parameters of the tunable dielectric layer includes: A control signal is applied to the metasurface structure to change the electromagnetic parameters of the tunable dielectric layer; At frequency band 1, adjust the reflected phase for the X-polarized incident wave; Alternatively, at frequency band 2, adjust the reflection phase for the Y-polarized incident wave.

5. The low-orbit satellite common-aperture antenna feeding device according to claim 4, characterized in that, Both frequency band 1 and frequency band 2 can select corresponding electromagnetic parameter combinations with a phase difference of 180°, which are mapped to 0 and 1 states in the digital domain to meet the dual-band 1-bit phase control requirements.

6. The low-orbit satellite common-aperture antenna feeding device according to claim 1, characterized in that, The metasurface structure comprises multiple units arranged in a preset manner to form a two-dimensional array, and the two-dimensional array arranges 0 and 1 units in a digital encoding manner.

7. The low-orbit satellite common-aperture antenna feeding device according to any one of claims 1-6, characterized in that, Each unit is a five-layer stacked structure, which consists of a quartz glass layer, a metal patch layer, an adjustable dielectric layer, a metal ground layer, and a quartz glass substrate from top to bottom. The unit size of each cell is on a subwavelength scale.

8. The low-orbit satellite common-aperture antenna feeding device according to claim 7, characterized in that, The control unit includes a bias circuit connected to the metal patch layer and the metal ground layer; The bias circuit is used to apply a control signal between the metal patch layer and the metal ground layer through a bias line to form an electric field in the tunable dielectric layer, thereby controlling the electromagnetic parameters of the tunable dielectric layer.

9. A method for feeding a low-orbit satellite common-aperture antenna using the method described in any one of claims 1-8, characterized in that, Applied to the control unit, the method includes: In response to communication mission instructions, the mission requirements are parsed to determine the target frequency band and beam direction; Based on the target frequency band and beam direction, the resonant parameters in the X and Y directions are calculated and matched using the geometric features of the metal patch layer to determine the phase characteristics that each unit in the metasurface structure should possess. According to the required phase characteristics and phase distribution, a dynamic bias voltage is applied to the tunable dielectric layer to adjust the electromagnetic parameters of the tunable dielectric layer, thereby changing the electromagnetic response of the metasurface structure and realizing independent transmission and reception of multi-band signals and beam control.

10. The method for feeding a low-orbit satellite common-aperture antenna according to claim 9, wherein adjusting the electromagnetic parameters of the tunable dielectric layer to change the electromagnetic response of the metasurface structure comprises: A control signal is applied to the metasurface structure to change the electromagnetic parameters of the tunable dielectric layer; At frequency band 1, adjust the reflected phase for the X-polarized incident wave; Alternatively, at frequency band 2, adjust the reflection phase for the Y-polarized incident wave.

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