A design method for auxiliary antennas of satellite communication ground stations under multi-source interference

Abstract

This application belongs to the field of communication technology, specifically disclosing a design method for auxiliary antennas of satellite communication ground stations under multi-source interference. The method includes: determining multiple technical specifications for auxiliary antennas, including: multi-directional saturation interference constraints, auxiliary antenna gain coverage constraints, auxiliary antenna sidelobe constraints, and anti-multi-interference resolution constraints; and designing auxiliary antennas through iterative optimization based on these constraints and the auxiliary antenna structure configuration, with minimizing the number of auxiliary antennas as the optimization objective. This application incorporates the requirements of an adaptive sidelobe cancellation algorithm for auxiliary antenna design into the auxiliary antenna technical specifications, and combines this with iterative optimization under multi-source interference conditions, achieving effective closed-loop optimization and improving the optimization efficiency of auxiliary antennas.

Description

Technical Field

[0001] This application belongs to the field of communication technology, and more specifically, relates to a design method for an auxiliary antenna for a satellite communication ground station under multi-source interference. Background Technology

[0002] The research on anti-interference of satellite communication ground stations is mainly divided into two stages: the problem exposure stage, in which the Friesian transmission formula is mainly used to approximate the safe distance between the satellite communication ground station system and the land interference source; and the problem solving stage, in which adaptive sidelobe cancellation technology is mainly used to explore anti-interference.

[0003] With the development of radar anti-jamming technology, adaptive sidelobe cancellation technology has been gradually introduced into satellite communication ground station anti-jamming systems. Related studies employ low-frequency signal modulation and complex detection techniques. Even when the satellite downlink useful signal and interference signal co-channel, the cancellation ratio measured in the field still reaches over 40dB. However, due to the lack of a low-noise amplifier, the useful signal is lost by approximately 3.5dB. Related studies analyze the broadband cancellation scenario of a satellite communication ground station system based on path difference. When the direction of the incoming interference wave is unknown (assuming the main antenna aperture is approximately 100λ and the auxiliary antenna is an omnidirectional small-aperture antenna), the optimal number of sampling antennas is 5, and the element spacing is 55λ. Related studies also propose a method for minimizing in-band power for satellite communication ground station anti-jamming. For a main antenna with an aperture of 1.2m (VAST station) and an auxiliary antenna with an aperture of 100m×90mm (horn antenna), a cancellation ratio of approximately 25dB was obtained in tests. However, existing research cannot effectively decompose the various technical specifications required for auxiliary antenna design once the interference suppression requirements of the system (cancellation ratio, useful signal loss) are given. The technical specifications of the auxiliary antenna are relatively separate from the adaptive sidelobe cancellation algorithm, resulting in low efficiency for optimizing the auxiliary antenna. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this application is to improve the optimization efficiency of auxiliary antennas.

[0005] To achieve the above objectives, in a first aspect, this application provides a method for designing an auxiliary antenna for a satellite communication ground station under multi-source interference, comprising:

[0006] Several auxiliary antenna technical specifications were determined, including: multi-directional saturation interference constraint I≤M≤N, and auxiliary antenna gain coverage constraint G. a ≥g ani Auxiliary antenna sidelobe constraint g an -g ani ≤g SLL and multi-interference resolution constraint Δθ c ≤Δθ a ≤Δθs ;

[0007] Based on multi-directional saturation interference constraints, auxiliary antenna gain coverage constraints, auxiliary antenna sidelobe constraints, anti-multi-interference resolution constraints, and auxiliary antenna structure configuration, the auxiliary antenna is designed through iterative optimization with minimizing N as the optimization objective.

[0008] Where I represents the number of interference sources, N represents the number of auxiliary antennas, M represents the number of auxiliary antennas required for effective coverage of any point on the azimuth plane, and G... a g represents the auxiliary antenna gain coverage index. ani G represents the gain of the nth auxiliary antenna in the i-th interference direction. an G represents the gain of the nth auxiliary antenna in the direction of the useful signal arrival. SLL The auxiliary antenna sidelobe index, Δθ c Δθ represents the minimum included angle that can effectively eliminate multiple interferences. a Δθ represents the resolution of the auxiliary antenna against multiple interference sources. s This indicates the resolution of the main antenna against multiple interference sources, while the auxiliary antenna structure configuration is used to indicate the components included in the auxiliary antenna and the relative positions between different components.

[0009] In one possible implementation, g is further determined by the following steps. an and g ani :

[0010] Based on analytical expressions, cancellation ratio ICR, and loss of useful signal S loss Determine g an and g ani ;

[0011] The parsing expression is as follows:

[0012] (g an ,g ani )=f(ICR,S loss );

[0013] Here, f(·) represents an analytic function.

[0014] In one possible implementation, the parsing expression is determined by the following steps:

[0015] Establish elimination ratio ICR, g an and g ani The first relation between them;

[0016] Establish the useful signal loss S loss g an and g ani The second relation between them;

[0017] Based on the first and second relations, the analytical expression is determined through analytical analysis.

[0018] In one possible implementation, the first relation is as follows:

[0019]

[0020] Among them, g m This represents the gain of the main antenna in the direction of the useful signal arrival wave, g. mi This represents the gain of the main antenna in the i-th interference direction.

[0021] In one possible implementation, the second relation is as follows:

[0022] S loss =||(g m -W o ·g an )·s+(g mi -W o ·g ani )·c i +(N m -W o ·N an )|| 2 / ||g m ·s+N m || 2 ;

[0023] Among them, g m This represents the gain of the main antenna in the direction of the useful signal arrival wave, g. mi W represents the gain of the main antenna in the i-th interference direction. o Let s represent the weights, s represent the useful signal, and c represent the weights. i N represents the i-th interference signal. m N represents the channel noise corresponding to the main antenna. an This represents the channel noise corresponding to the nth auxiliary antenna.

[0024] In one possible implementation, the auxiliary antenna structure configuration is specifically used to indicate the following information:

[0025] The auxiliary antenna includes two rectangular radiating patches, a T-shaped power divider, an elliptical ring parasitic radiating patch, and a rectangular dielectric wall;

[0026] An elliptical ring parasitic radiation patch is set inside a rectangular dielectric wall, and two rectangular radiation patches and a T-shaped power divider are set inside the elliptical ring parasitic radiation patch.

[0027] Two rectangular radiating patches are connected by a T-shaped power divider to obtain an initial elliptical beam;

[0028] Elliptical ring parasitic radiation patch is used to widen the beamwidth of the H-plane based on the initial elliptical beam to obtain an elliptical beam with widened beamwidth.

[0029] A rectangular dielectric wall is used to modify the beamwidth of the E-plane and H-plane based on the elliptical beam after beamwidth widening, in order to obtain the target elliptical beam.

[0030] In one possible implementation, based on multi-directional saturation interference constraints, auxiliary antenna gain coverage constraints, auxiliary antenna sidelobe constraints, anti-multi-interference resolution constraints, and auxiliary antenna structure configuration, the auxiliary antenna is designed through iterative optimization with the goal of minimizing N, including:

[0031] Determine the radiation fields of two rectangular radiation patches, the radiation field of an elliptical annular parasitic radiation patch, and the radiation field of a rectangular dielectric wall;

[0032] A simulation model of an auxiliary antenna is established based on the radiation fields of two rectangular radiating patches, the radiation field of an elliptical ring parasitic radiating patch, and the radiation field of a rectangular dielectric wall.

[0033] Based on the simulation results provided by the multi-directional saturation interference constraint, auxiliary antenna gain coverage constraint, auxiliary antenna sidelobe constraint, anti-multi-interference resolution constraint, and auxiliary antenna simulation model, the design parameters of the auxiliary antenna are determined by iterative optimization with minimizing N as the optimization objective.

[0034] In one possible implementation, determining the radiation fields of two rectangular radiating patches, the radiation field of the elliptical annular parasitic radiating patch, and the radiation field of the rectangular dielectric wall includes:

[0035] The radiation fields of two rectangular radiation patches and the rectangular dielectric wall were calculated using a cavity model.

[0036] Determine the current distribution of the elliptical annular parasitic radiation patch;

[0037] Based on the current distribution of the elliptical ring parasitic radiation patch, the radiation field of the elliptical ring parasitic radiation patch is calculated using the Huygens principle.

[0038] Secondly, this application provides an antenna system, including a main antenna and multiple auxiliary antennas, wherein the multiple auxiliary antennas are designed using any of the above-mentioned multi-source interference-based satellite communication ground station auxiliary antenna design methods.

[0039] In one possible implementation, the auxiliary antenna includes: two rectangular radiating patches, a T-shaped power divider, an elliptical ring parasitic radiating patch, and a rectangular dielectric wall;

[0040] An elliptical ring parasitic radiation patch is set inside a rectangular dielectric wall, and two rectangular radiation patches and a T-shaped power divider are set inside the elliptical ring parasitic radiation patch.

[0041] Two rectangular radiating patches are connected by a T-shaped power divider to obtain an initial elliptical beam;

[0042] Elliptical ring parasitic radiation patch is used to widen the beamwidth of the H-plane based on the initial elliptical beam to obtain an elliptical beam with widened beamwidth.

[0043] A rectangular dielectric wall is used to modify the beamwidth of the E-plane and H-plane based on the elliptical beam after beamwidth widening, in order to obtain the target elliptical beam.

[0044] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art:

[0045] The essential requirement of adaptive sidelobe cancellation algorithm for auxiliary antenna design is that the auxiliary antenna gain g in the interference direction is... ani The gain g should be as large as possible in the direction of the useful signal. an To minimize this requirement, the sidelobe size can be used as a constraint on the auxiliary antenna. Simultaneously, under multi-source interference, constraints on multi-directional saturation interference, auxiliary antenna gain coverage, and multi-interference resolution must also be met. Therefore, under these constraints, the auxiliary antenna can be iteratively optimized by minimizing N, based on the components included in the auxiliary antenna and their relative positions. This allows for effective coverage of I interference sources at a given elevation angle and 360° azimuth angle with the minimum number of auxiliary antennas N, while satisfying the constraints on auxiliary antenna gain coverage and sidelobe size, and simultaneously addressing multi-interference resolution requirements. By incorporating the requirements of the adaptive sidelobe cancellation algorithm into the auxiliary antenna design specifications and iteratively optimizing the design under multi-source interference, an effective closed-loop optimization can be achieved, improving the efficiency of auxiliary antenna optimization. Attached Figure Description

[0046] Figure 1 This is one of the flowcharts illustrating the design method for auxiliary antennas of satellite communication ground stations under multi-source interference provided in the embodiments of this application;

[0047] Figure 2 This is the second flowchart illustrating the design method for auxiliary antennas of satellite communication ground stations under multi-source interference provided in this application embodiment;

[0048] Figure 3 This is a schematic diagram of the design principle of the magnetoelectric dipole elliptical beam-assisted antenna provided in the embodiments of this application;

[0049] Figure 4 This is a diagram illustrating the single-wire transmission line model analysis method for linear microstrip antennas provided in this application embodiment;

[0050] Figure 5 This is a diagram illustrating the single-wire transmission line model analysis method for an elliptical ring microstrip antenna provided in this application embodiment.

[0051] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0052] 10: T-shaped power divider; 20: rectangular radiating patch; 30: dielectric substrate; 40: elliptical ring parasitic radiating patch; 50: rectangular dielectric wall. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0054] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0055] In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, for example, multiple processing units means two or more processing units, multiple elements means two or more elements, etc.

[0056] The embodiments of this application are described below with reference to the accompanying drawings.

[0057] Figure 1 This is one of the flowcharts illustrating the design method for auxiliary antennas of satellite communication ground stations under multi-source interference provided in this application embodiment, such as... Figure 1 As shown, the method includes the following steps S101 and S102.

[0058] Step S101: Determine multiple auxiliary antenna technical specifications, including: multi-directional saturation interference constraint I≤M≤N, auxiliary antenna gain coverage constraint G. a ≥g ani Auxiliary antenna sidelobe constraint g an -g ani ≤g SLL and multi-interference resolution constraint Δθ c ≤Δθ a ≤Δθ s ;

[0059] Where I represents the number of interference sources, N represents the number of auxiliary antennas, M represents the number of auxiliary antennas required for effective coverage of any point on the azimuth plane, and G... a g represents the auxiliary antenna gain coverage index. ani G represents the gain of the nth auxiliary antenna in the i-th interference direction. an G represents the gain of the nth auxiliary antenna in the direction of the useful signal arrival. SLL The auxiliary antenna sidelobe index, Δθ c Δθ represents the minimum included angle that can effectively eliminate multiple interferences. a Δθ represents the resolution of the auxiliary antenna against multiple interference sources. s This indicates the resolution of the main antenna against multiple interference sources, and the auxiliary antenna structure configuration is used to indicate the components included in the auxiliary antenna and the relative positions between the different components.

[0060] Step S102: Based on multi-directional saturation interference constraints, auxiliary antenna gain coverage constraints, auxiliary antenna sidelobe constraints, anti-multi-interference resolution constraints, and auxiliary antenna structure configuration, the auxiliary antenna is designed through iterative optimization with minimizing N as the optimization objective.

[0061] For iterative optimization, simulation tools can be used for iterative optimization; alternatively, simulation tools can be used for the first stage of iterative optimization, and a physical prototype of the auxiliary antenna can be used for the second stage of iterative optimization.

[0062] Understandably, the adaptive sidelobe cancellation algorithm inherently requires the auxiliary antenna design to have a gain g in the interference direction. ani The gain g should be as large as possible in the direction of the useful signal. an To minimize this requirement, the sidelobe size can be used as a constraint on the auxiliary antenna. Simultaneously, under multi-source interference, constraints on multi-directional saturation interference, auxiliary antenna gain coverage, and multi-interference resolution must also be met. Therefore, under these constraints, the auxiliary antenna can be iteratively optimized by minimizing N, based on the components included in the auxiliary antenna and their relative positions. This allows for effective coverage of I interference sources at a given elevation angle and 360° azimuth angle with the minimum number of auxiliary antennas N, while satisfying the constraints on auxiliary antenna gain coverage and sidelobe size, and simultaneously addressing multi-interference resolution requirements. By incorporating the requirements of the adaptive sidelobe cancellation algorithm into the auxiliary antenna design specifications and iteratively optimizing the design under multi-source interference, an effective closed-loop optimization can be achieved, improving the efficiency of auxiliary antenna optimization.

[0063] In one possible implementation, g is further determined by the following steps. an and gani Based on analytical expressions, cancellation ratio ICR, and loss S for the useful signal loss Determine g an and g ani The parsed expression is as follows: (g an ,g ani )=f(ICR,S loss ).

[0064] Optionally, the analytical expression is determined through the following steps: establishing the cancellation ratio ICR, g an and g ani The first relationship between them; establishing the useful signal loss S loss g an and g ani The second relation between the first and second relations is determined; based on the first and second relations, the analytical expression is determined through analytical analysis.

[0065] For example, the first relation is as follows:

[0066]

[0067] Among them, g m This represents the gain of the main antenna in the direction of the useful signal arrival wave, g. mi This represents the gain of the main antenna in the i-th interference direction.

[0068] The second relation is as follows:

[0069] S loss =||(g m -W o ·g an )·s+(g mi -W o ·g ani )·c i +(N m -W o ·N an )|| 2 / ||g m ·s+N m || 2 ;

[0070] Among them, g m This represents the gain of the main antenna in the direction of the useful signal arrival wave, g. mi W represents the gain of the main antenna in the i-th interference direction. o Let s represent the weights, s represent the useful signal, and c represent the weights. i N represents the i-th interference signal. m N represents the channel noise corresponding to the main antenna. an This represents the channel noise corresponding to the nth auxiliary antenna.

[0071] In one possible implementation, the auxiliary antenna structure is specifically configured to indicate the following information: the auxiliary antenna includes two rectangular radiating patches, a T-shaped power divider, an elliptical ring parasitic radiating patch, and a rectangular dielectric wall.

[0072] Specifically, an elliptical ring parasitic radiating patch is disposed within a rectangular dielectric wall, and two rectangular radiating patches and a T-shaped power divider are disposed within the elliptical ring parasitic radiating patch. The two rectangular radiating patches are connected by the T-shaped power divider to obtain an initial elliptical beam. The elliptical ring parasitic radiating patch is used to widen the beamwidth of the H-plane based on the initial elliptical beam to obtain an elliptical beam with widened beamwidth. The rectangular dielectric wall is used to correct the beamwidth of the E-plane and H-plane based on the elliptical beam with widened beamwidth to obtain a target elliptical beam (or expected elliptical beam). This enables effective coverage of any direction with multiple interferences with minimal number of auxiliary antennas and is easy to integrate with RF devices.

[0073] The E-plane (Electric Field Plane) is a plane perpendicular to and encompassing the antenna's axis. The electric field component is at its maximum in this plane, hence the name E-plane. The E-plane is commonly used to observe the antenna's radiation patterns in the horizontal direction.

[0074] The H-plane (Magnetic Field Plane) is a plane perpendicular to the antenna axis but does not encompass it. The magnetic field component is strongest in this plane, hence the name H-plane. The H-plane is commonly used to observe the antenna's radiation patterns in the vertical direction.

[0075] In one possible implementation, the above-mentioned optimization based on multi-directional saturation interference constraints, auxiliary antenna gain coverage constraints, auxiliary antenna sidelobe constraints, anti-multi-interference resolution constraints, and auxiliary antenna structural configuration, with minimizing N as the optimization objective, is carried out through an iterative optimization method, including: determining the radiation fields of the two rectangular radiating patches, the elliptical ring parasitic radiating patch, and the rectangular dielectric wall; establishing an auxiliary antenna simulation model based on the radiation fields of the two rectangular radiating patches, the elliptical ring parasitic radiating patch, and the rectangular dielectric wall; and determining the design parameters of the auxiliary antenna through an iterative optimization method with minimizing N as the optimization objective, based on the simulation results provided by the multi-directional saturation interference constraints, auxiliary antenna gain coverage constraints, auxiliary antenna sidelobe constraints, anti-multi-interference resolution constraints, and auxiliary antenna simulation model.

[0076] For example, the design parameters of the auxiliary antenna may include: the geometric parameters of the auxiliary antenna (including size and shape), the material properties of the auxiliary antenna, the feeding method of the auxiliary antenna, and the spacing between the auxiliary antennas, etc. The simulation results provided by the auxiliary antenna simulation model may include: return loss simulation data, bandwidth simulation data, gain simulation data, and radiation pattern simulation data, etc.

[0077] During the iterative optimization process, under the above constraints, the optimization objective can be to minimize N. The simulation results can be continuously obtained using the auxiliary antenna simulation model, and the design parameters of the auxiliary antenna can be adjusted according to the simulation results until the iteration stopping condition is met (e.g., the preset maximum number of iterations is reached).

[0078] Optionally, determining the radiation fields of the two rectangular radiating patches, the elliptical ring parasitic radiating patch, and the rectangular dielectric wall includes: calculating the radiation fields of the two rectangular radiating patches and the rectangular dielectric wall using a cavity model; determining the current distribution of the elliptical ring parasitic radiating patch; and calculating the radiation field of the elliptical ring parasitic radiating patch using the Huygens principle based on the current distribution of the elliptical ring parasitic radiating patch.

[0079] Cavity models are primarily used to study and analyze the propagation characteristics of electromagnetic waves in different media. These models are commonly used in fields such as radio wave propagation, antenna design, and microwave engineering. A cavity model simplifies a complex electromagnetic environment into one or more cavities with specific boundary conditions, facilitating mathematical analysis and calculation.

[0080] Figure 2 This is the second flowchart illustrating the design method for auxiliary antennas of satellite communication ground stations under multi-source interference provided in this application embodiment. Figure 2 As shown, to obtain the technical specifications of the auxiliary antenna, we can combine the adaptive sidelobe cancellation algorithm and the working scenario of the satellite communication ground station to analyze the gain coverage requirements of the auxiliary antenna array. Furthermore, we can analyze the multi-source interference resolution requirements by using the complex vector similarity metric of interference waves. Then, by combining the gain coverage requirements, multi-source interference resolution requirements, and interference suppression requirements of the auxiliary antenna array, we can obtain the technical specifications of the auxiliary antenna through approximate analytical analysis. A magnetoelectric dipole microstrip antenna can be designed by combining a double-rectangular radiating patch electric dipole with an elliptical ring parasitic radiating patch magnetic dipole. Then, by combining the technical specifications of the auxiliary antenna and the magnetoelectric dipole microstrip antenna, and through experimental verification and iterative improvement, a low-profile elliptical wide-beam auxiliary antenna can be obtained.

[0081] The auxiliary antenna design method provided in this application is illustrated below with an example.

[0082] In this example, the adaptive sidelobe cancellation algorithm is reasonably decoupled, and the design of the satellite communication ground station auxiliary antenna is decoupled into the analysis of the auxiliary antenna array gain requirements. Considering the array manifold, it is assumed that there are I interference sources and N auxiliary antennas, and the main antenna receives a signal X. m The auxiliary antenna received signal X an They are respectively:

[0083]

[0084]

[0085] Among them, s, c i These represent the useful signal and the interference signal, respectively. m G an The radiation patterns of the main antenna and auxiliary antenna are shown separately. The directions of the incoming useful signal and the interference signal are respectively, N. m N m These are the main channel and auxiliary channel noises, respectively, f n0 f s0 f ci Let X be the auxiliary antenna position vector, the useful signal arrival vector, and the interference signal arrival vector, respectively. Σ represents the summation sign, and k represents the spatial propagation constant. For ease of derivation, X... m X an It can be abbreviated as:

[0086] X m =s·g m +∑c i ·g mi +N m ;

[0087] X an =s·g an +∑c i ·g ani +N an ;

[0088] Among them, the gain of the main antenna in the direction of the useful signal arrival wave. The gain of the main antenna in the i-th interference direction The gain of the nth auxiliary antenna in the direction of the useful signal arrival wave The gain of the nth auxiliary antenna in the i-th interference direction

[0089] Under ideal conditions, adaptive sidelobe cancellation technology only eliminates interference signals in the signal received by the main antenna, and the optimal weight W opt for:

[0090] W opt =min||∑c i ·gmi -W H c a || 2 ;

[0091] Where min represents finding the minimum value, |·| 2 Indicates calculated power, W H Let represent the initial weights, and we have:

[0092] C a =[∑c i ·g a1i ∑c i ·g a2i …∑c i ·g aNi ];

[0093] The weights W are usually calculated using the classic Wiener solution. o :

[0094] W o =R aa -1 ·R am ;

[0095] Among them, R aa -1 R represents the autocorrelation matrix of the signal received by the auxiliary antenna. am This represents the cross-correlation matrix of the signals received by the main antenna and the auxiliary antenna.

[0096] At this point, it is necessary to solve the covariance matrix, which is precisely why the adaptive sidelobe cancellation algorithm cannot be fully analytically derived. This application decouples the auxiliary antenna gain coverage requirement that affects the adaptive sidelobe cancellation effect (cancellation ratio, degradation of useful signal). Taking a single interference and a single auxiliary antenna (I=1, N=1) as an example, assuming that the noise power of the main antenna and auxiliary antenna channels is equivalent, and considering that the main antenna of a satellite communication ground station usually adopts a high-gain parabolic antenna with a typical sidelobe level of about -40dB, then:

[0097] W o ≈W opt +(g a1 ·g m ·σ s 2 ) / (||g a11 || 2 ·σ s1 2 );

[0098] Among them, g a1 σ represents the gain of a single auxiliary antenna in the direction of the incoming useful signal. s 2 G represents the noise power of the main antenna channel.a11 σ represents the gain of a single auxiliary antenna in the interference direction. s1 2 This indicates the noise power of the main antenna channel.

[0099] The cancellation ratio (ICR) is defined as the ratio of the signal-to-interference-plus-noise ratio (SIR) of the signal before and after cancellation.

[0100]

[0101] Loss of useful signal S loss :

[0102] S loss =||(g m -W o ·g a1 )·s+(g m1 -W o ·g a11 )·c1+(N m -W o ·N a1 )|| 2 / ||g m ·s+N m || 2 ;

[0103] Therefore, considering ICR, S loss Ignoring the array factor for the time being, the most fundamental requirement of the adaptive sidelobe cancellation algorithm for auxiliary antenna design is that the auxiliary antenna gain g in the interference direction is... a11 The gain g should be as large as possible in the direction of the useful signal. a1 As small as possible (corresponding to the sidelobe level g of the auxiliary antenna) SLL (Constraints), and appropriately reduce the weight W o Given the number of auxiliary antennas N, this is a combinatorial optimization problem. To facilitate auxiliary antenna design, based on the above formulas for ICR and Sloss, we can establish (ICR, Sloss = ...). loss ) and (g a1 ,g a11 The parsing expression for ) is:

[0104] (g a1 ,g a11 )=f(ICR,S loss );

[0105] To avoid invalid weights, the main antenna weight W can be constrained. m =1, Auxiliary antenna weight W a1 ≤1, via ICR, S lossRobustness analysis of different auxiliary antenna array configurations, different useful signals and interference signals, and different channel noise can quantitatively provide the auxiliary antenna gain coverage requirements.

[0106] Antenna resolution means that when the main beam formed by the antenna is aligned with the direction of arrival of one signal, the direction of arrival of the other signal is exactly located at the antenna's first null point. The angle between these two directions of arrival is the antenna resolution. When multiple interferences exist, in addition to meeting the auxiliary antenna gain coverage requirements mentioned above, according to the principle of multi-directional saturation interference, the number of auxiliary antennas needs to be greater than the number of interference sources. The minimum angle that can effectively cancel multiple interferences is defined as the interference resolution Δθ. c The resolution of the main antenna against multiple interference sources is Δθ s The auxiliary antenna has a resolution of Δθ for multiple interference sources. a Then there should be Δθ c ≤Δθ a ≤Δθ s When the angle between multiple interference sources is less than Δθ c At this time, it is the blind zone for multiple interference cancellation.

[0107] To quickly analyze the auxiliary antenna resolution Δθ a This application proposes a method for measuring the similarity of the complex vectors of the incoming interference waves. The complex vector of the main antenna in the direction of the incoming interference wave is:

[0108] G M =[g m1 g m2 …g mi …g mI ] T ;

[0109] The complex matrix of the auxiliary antenna in the direction of the incoming interference wave is:

[0110] G A =[G a1i G a2i …G ani …G aNi ];

[0111] Among them, G ani =[g an1 g an2 …g ani …g anI ] T .

[0112] Similarity metrics are commonly used to estimate the degree of similarity between different samples, often serving as a criterion for classification problems to evaluate the similarity and category of individuals. Vector space cosine similarity uses the cosine of the angle between two vectors to measure their correlation. For example, if the gain requirement of a fixed auxiliary antenna (g) is...a1 ,g a11 For multi-interference auxiliary antenna design, the most fundamental requirement of the adaptive sidelobe cancellation algorithm for the auxiliary antenna is that the complex vectors of the incoming interference waves have similarity. Therefore, by analyzing G... M G A The similarity measure of the assembled small augmented matrix is ​​to calculate the similarity between the eigenvectors (A, B) corresponding to the two largest eigenvalues ​​of the matrix.

[0113] Suppose that the eigenvectors corresponding to the two largest eigenvalues ​​of a matrix are A and B, then the formula for calculating the similarity between A and B is as follows:

[0114] C e =A·B / (||A||×||B||);

[0115] C e The range is between [-1, 1]. The closer the value is to 1, the closer the directions of the two vectors are, and the better the resolution. The closer the value is to -1, the more opposite their directions are. The closer the value is to 0, the more orthogonal the two vectors are, and the worse the resolution is.

[0116] The auxiliary antenna coverage theory mainly studies how to achieve effective coverage of I interference sources from any direction at a certain elevation angle and 360° azimuth angle with the minimum number of auxiliary antennas N, while ensuring that the coverage performance of the auxiliary antenna gain satisfies the constraint condition G. a ≥g ani (Ignoring array factor), the auxiliary antenna sidelobes satisfy constraint condition g. an -g ani ≤g SLL At the same time, it also takes into account the resolution requirements of multiple interferences.

[0117] Assuming that M auxiliary antennas are effectively covered at any point in the far field on the azimuth plane, the decomposition model of the auxiliary antenna technical specifications is as follows:

[0118] Minimize the objective N;

[0119] Solution conditions:

[0120] I≤M≤N, principle of multi-directional saturation interference;

[0121] G a ≥g ani Auxiliary antenna gain coverage requirements;

[0122] g an -g ani ≤g SLL Auxiliary antenna sidelobe constraint;

[0123] Δθ c ≤Δθ a ≤Δθ sResistant to multiple interference resolution constraints;

[0124] G an =η·4π / (θ) E ·θ H ), Empirical formula for antenna gain;

[0125] Where η is the antenna efficiency, θ E θ H G represents the beamwidth of the antenna's E-plane and H-plane, respectively. SLL To assist the antenna sidelobes.

[0126] Figure 3 This is a schematic diagram of the design principle of a magnetoelectric dipole elliptical beam-assisted antenna provided in an embodiment of this application, such as... Figure 3 As shown, to minimize the number of auxiliary antennas and integrate them with RF devices, this application adopts a low-profile elliptical wide-beam auxiliary antenna design based on a magnetoelectric dipole. First, a dual-radiating rectangular patch 20 and a T-shaped power divider 10 are set on the dielectric substrate 30 to obtain an initial elliptical beam (approximately 100° in the H-plane). Second, an elliptical ring parasitic radiating patch 40 is used to further widen the beam width in the H-plane. Then, a rectangular dielectric wall 50 is used to correct the beam widths in the E-plane and H-plane to achieve the desired elliptical beam.

[0127] The resonant characteristics of the radiation fields of dual-radiating patches, elliptical ring parasitic patches, and dielectric wall patches, as well as the radiation characteristics of dual-radiating patches and dielectric wall patches, can be analyzed using cavity mode theory. For the radiation field of elliptical ring parasitic patches, the core is to calculate the field source distribution of the elliptical ring microstrip antenna. This application uses a single-wire transmission line model based on Kirchhoff's law to calculate the surface current distribution of the elliptical ring parasitic radiating patch, enabling rapid analytical solution of its external field radiation.

[0128] by Figure 3 Taking the receiving antenna shown as an example, Figure 4 This is a diagram illustrating the single-wire transmission line model analysis method for linear microstrip antennas provided in this application embodiment, as shown below. Figure 4 As shown, the incident tangential component E at any point on any center line of any strip on a microstrip antenna element i The unified expression for (ξ) is:

[0129]

[0130] Where E0 is the incident electric field amplitude, n v n h These are the vertical and horizontal vectors, respectively, where Φ is the scanning angle and p is the horizontal vector. i Let β0 be the element reference direction vector, θ be the propagation constant, and θ be the propagation direction vector. These are the incoming wave elevation angle and the incoming wave azimuth angle, respectively. 0i x 0iLet be the starting points of the i-th segment of the element on the x-axis and z-axis, respectively, and let ξ be a point on the element. Then:

[0131]

[0132] Among them, l i x is the length of the i-th segment of the unit. 1i z 1i These represent the start and end points of the i-th segment of the unit on the x-axis and z-axis, respectively.

[0133] The tangential component of the incident electric field on the unit cell E i (ξ) can be used to establish an equivalent transmission line model, and the transmission line equation is:

[0134]

[0135]

[0136] Where V(ξ) and I(ξ) are the transmission line potential and current distribution, respectively, ω is the angular frequency, and L and C are the unit transmission line inductance and capacitance, respectively. Figure 4 In this equation, ρ represents the radius of the transmission line. The general solution to the above transmission line equation is:

[0137] V(ξ)=A·exp(-rξ)+B·exp(rξ)+v(ξ);

[0138] I(ξ)=[A·exp(-rξ)-B·exp(rξ)+i(ξ) / r] / Z c ;

[0139] Where v(ξ) and i(ξ) are related to E i (ξ) Related known terms, r, Z c Let A and B be the equivalent transmission line propagation constant and characteristic impedance, respectively, and A and B be the coefficients to be determined. Based on the equivalent transmission line model, the potential and current boundary conditions are established using Kirchhoff's circuit law, allowing the calculation of the potential and current distribution of the microstrip antenna element. For cases with a relatively small number of segments in the equivalent transmission line, analytical expressions can be directly derived; however, when the number of segments is relatively large, the analytical derivation becomes too complex, and a sparse strip matrix analysis method can be used for rapid solution.

[0140] For the curved structure of the elliptical annular parasitic radiation patch, the elliptical annular unit can be divided into J small segments. Figure 5 This is a diagram illustrating the single-wire transmission line model analysis method for an elliptical ring microstrip antenna provided in an embodiment of this application, as shown below. Figure 5As shown, an approximate simulation can be achieved when J = 30, thus establishing a single-wire transmission line model based on Kirchhoff's law. Since the elliptical ring parasitic radiation patch is not directly excited but rather excited through surface wave coupling, this application uses a dielectric wall to further correct the radiation pattern. Once the current distribution of the elliptical ring is solved, the radiation field can be calculated according to Huygens' principle, and superimposed with the radiation fields of the rectangular patch and dielectric wall calculated by the cavity model to obtain the expected elliptical wide-beam characteristics.

[0141] It is understood that the above-mentioned design method provided in this application has the following beneficial effects compared with the prior art: (1) This application focuses on the design of anti-interference auxiliary antennas for satellite communication ground stations, reasonably decouples the adaptive sidelobe cancellation algorithm, proposes an approximate analytical analysis method for auxiliary antennas under multi-target coupling conditions, establishes a simplified mathematical model, and can quickly analyze the influence of auxiliary antennas on cancellation performance from a mechanistic perspective, guiding the specific design of auxiliary antennas. (2) This application combines theory and engineering, and proposes a low-profile elliptical wide-beam auxiliary antenna design idea to achieve effective coverage of arbitrary multi-interference with the fewest auxiliary antennas and integrate them with radio frequency devices. The results can be directly applied to the anti-interference adaptive sidelobe cancellation system of satellite communication ground stations. (3) The research on auxiliary antennas in this application is general and can be extended to other anti-interference systems, such as radar, satellite navigation, ultra-shortwave, 5G, and spaceborne anti-interference.

[0142] This application also provides an antenna system, including a main antenna and multiple auxiliary antennas, wherein the multiple auxiliary antennas are designed using any of the above-described multi-source interference-based satellite communication ground station auxiliary antenna design methods.

[0143] In one possible implementation, the auxiliary antenna includes: two rectangular radiating patches, a T-shaped power divider, an elliptical ring parasitic radiating patch, and a rectangular dielectric wall; the elliptical ring parasitic radiating patch is disposed within the rectangular dielectric wall, and the two rectangular radiating patches and the T-shaped power divider are disposed within the elliptical ring parasitic radiating patch; the two rectangular radiating patches are connected by the T-shaped power divider to obtain an initial elliptical beam; the elliptical ring parasitic radiating patch is used to widen the H-plane beamwidth based on the initial elliptical beam to obtain a widened elliptical beam; the rectangular dielectric wall is used to correct the E-plane beamwidth and the H-plane beamwidth based on the widened elliptical beam to obtain a target elliptical beam.

[0144] The above description is merely a specific 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. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for designing an auxiliary antenna for a satellite communication ground station under multi-source interference, characterized in that, include: Several auxiliary antenna technical specifications were determined, including: multi-directional saturation interference constraint. Auxiliary antenna gain coverage constraints Auxiliary antenna sidelobe constraint and multi-interference resolution constraints ; Based on the aforementioned multi-directional saturation interference constraints, auxiliary antenna gain coverage constraints, auxiliary antenna sidelobe constraints, anti-multi-interference resolution constraints, and auxiliary antenna structure configuration, to minimize The auxiliary antenna is designed using an iterative optimization method as the optimization objective; in, Indicates the number of interference sources. Indicates the number of auxiliary antennas. This indicates the number of auxiliary antennas required to effectively cover any point on the azimuth plane. This indicates the auxiliary antenna gain coverage index. Indicates the first The auxiliary antenna is in the first Gain in each interference direction Indicates the first The gain of each auxiliary antenna in the direction of the useful signal arrival wave. This indicates the sidelobe index of the auxiliary antenna. This represents the minimum included angle that can effectively eliminate multiple interferences. This indicates the resolution of the auxiliary antenna against multiple interference sources. This indicates the resolution of the main antenna against multiple interference sources, and the auxiliary antenna structure configuration is used to indicate the components included in the auxiliary antenna and the relative positions between the different components; It also includes determining through the following steps and : Based on analytical expressions and cancellation ratios ICR and loss of useful signal ,Sure and ; The parsing expression is as follows: ； in, This represents an analytic function.

2. The method for designing auxiliary antennas for satellite communication ground stations under multi-source interference according to claim 1, characterized in that, It also includes determining the parsing expression through the following steps: Establish a counter-comparison ratio ICR , and The first relation between them; Establish the loss of useful signal , and The second relation between them; Based on the first relation and the second relation, the analytical expression is determined through analytical analysis.

3. The method for designing auxiliary antennas for satellite communication ground stations under multi-source interference according to claim 2, characterized in that, The first relation is as follows: ； in, This indicates the gain of the main antenna in the direction of the incoming useful signal. Indicates the main antenna at the 1st Gain in each interference direction.

4. The method for designing auxiliary antennas for satellite communication ground stations under multi-source interference according to claim 2, characterized in that, The second relation is as follows: ； in, This indicates the gain of the main antenna in the direction of the incoming useful signal. Indicates the main antenna at the 1st Gain in each interference direction Indicates the weight. Indicates a useful signal. Indicates the first One interference signal, This indicates the channel noise corresponding to the main antenna. Indicates the first The channel noise corresponding to each auxiliary antenna.

5. The method for designing auxiliary antennas for satellite communication ground stations under multi-source interference according to claim 1, characterized in that, The auxiliary antenna structure configuration is specifically used to indicate the following information: The auxiliary antenna includes two rectangular radiating patches, a T-shaped power divider, an elliptical ring parasitic radiating patch, and a rectangular dielectric wall; The elliptical ring parasitic radiation patch is disposed within the rectangular dielectric wall, and the two rectangular radiation patches and the T-shaped power divider are disposed within the elliptical ring parasitic radiation patch; Two rectangular radiating patches are connected by a T-shaped power divider to obtain an initial elliptical beam; The elliptical ring parasitic radiation patch is used to widen the beamwidth of the H-plane based on the initial elliptical beam to obtain an elliptical beam with widened beamwidth. The rectangular dielectric wall is used to correct the beamwidths of the E-plane and H-plane based on the elliptical beamwidth after widening, so as to obtain the target elliptical beamwidth.

6. The method for designing auxiliary antennas for satellite communication ground stations under multi-source interference according to claim 5, characterized in that, The method is based on the multi-directional saturation interference constraint, the auxiliary antenna gain coverage constraint, the auxiliary antenna sidelobe constraint, the anti-multi-interference resolution constraint, and the auxiliary antenna structure configuration to minimize The auxiliary antenna is designed through iterative optimization as the optimization objective, including: Determine the radiation fields of the two rectangular radiation patches, the radiation field of the elliptical annular parasitic radiation patch, and the radiation field of the rectangular dielectric wall; An auxiliary antenna simulation model is established based on the radiation fields of the two rectangular radiating patches, the radiation field of the elliptical ring parasitic radiating patch, and the radiation field of the rectangular dielectric wall. Based on the simulation results provided by the multi-directional saturation interference constraint, the auxiliary antenna gain coverage constraint, the auxiliary antenna sidelobe constraint, the anti-multi-interference resolution constraint, and the auxiliary antenna simulation model, to minimize The design parameters of the auxiliary antenna are determined through iterative optimization, with the optimization objective serving as the target.

7. The method for designing auxiliary antennas for satellite communication ground stations under multi-source interference according to claim 6, characterized in that, Determining the radiation fields of the two rectangular radiation patches, the radiation field of the elliptical annular parasitic radiation patch, and the radiation field of the rectangular dielectric wall includes: The radiation fields of two rectangular radiation patches and the rectangular dielectric wall were calculated using a cavity model. Determine the current distribution of the elliptical annular parasitic radiation patch; Based on the current distribution of the elliptical annular parasitic radiation patch, the radiation field of the elliptical annular parasitic radiation patch is calculated using the Huygens principle.

8. An antenna system, characterized in that, include: The main antenna and multiple auxiliary antennas are designed using the satellite communication ground station auxiliary antenna design method under multi-source interference as described in any one of claims 1-7.

9. The antenna system according to claim 8, characterized in that, The auxiliary antenna includes: two rectangular radiating patches, a T-shaped power divider, an elliptical ring parasitic radiating patch, and a rectangular dielectric wall; The elliptical ring parasitic radiation patch is disposed within the rectangular dielectric wall, and the two rectangular radiation patches and the T-shaped power divider are disposed within the elliptical ring parasitic radiation patch; Two rectangular radiating patches are connected by a T-shaped power divider to obtain an initial elliptical beam; The elliptical ring parasitic radiation patch is used to widen the beamwidth of the H-plane based on the initial elliptical beam to obtain an elliptical beam with widened beamwidth. The rectangular dielectric wall is used to correct the beamwidths of the E-plane and H-plane based on the elliptical beamwidth after widening, so as to obtain the target elliptical beamwidth.

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