Modular analysis method for platform antenna interface response

Abstract

This invention belongs to the field of electromagnetic field numerical calculation technology, specifically proposing a modular analysis method for the interfaced response of a platform antenna. By constructing a unified interface mode space, the platform's external domain response and antenna radiation behavior are mapped to finite-dimensional mode coefficients, respectively. The platform response operator can be formed with only one full-wave solution. The antenna is connected in the form of a surrogate operator, and the interaction relationship between the two is established through an interface coupling operator. This method can quickly predict the comprehensive performance after different antenna installations without repeatedly solving the platform model, and is suitable for the engineering needs of antenna loading analysis in complex equipment.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic field numerical calculation technology, specifically to a method for constructing independent response models of a platform and antenna through an interface pattern space, which is used to realize modular and rapid analysis of a platform antenna combination system. Background Technology

[0002] In complex equipment such as aircraft, shipborne, and vehicle systems, antennas are typically mounted on metal or composite material platforms. Due to the significant scattering and reradiation effects of the platform itself, the antenna's radiation pattern, input impedance, and radiation efficiency, once mounted on the platform, often differ considerably from their free-space design values.

[0003] Traditional methods typically employ full-wave simulation of the platform and antenna as a whole. However, due to the large geometry and complex materials of the platform, solving it using the method of moments (MoM) or finite element method requires handling high-dimensional linear systems, resulting in very high computational costs. Especially when replacing the antenna, adjusting the installation position, or iteratively optimizing multiple schemes, the overall platform antenna model must be solved again each time, severely impacting engineering efficiency.

[0004] Therefore, it is necessary to develop a new analytical method that allows the platform to generate its external domain response model with only a single full-wave solution. The antenna, as an independent module, is connected to the platform through a unified interface mode space, enabling rapid prediction of the overall performance of different antennas installed on the platform. Summary of the Invention

[0005] The objective of this invention is to propose a modular analysis method for the interfaced response of a platform antenna. This method constructs an interface mode space, mapping the platform's external domain response and antenna radiation behavior to a unified mode coefficient space, and achieves a combined solution for both through mode coupling. The platform only requires a single full-wave solution, and the antenna model can be replaced, adjusted, or optimized without resimulation, thus significantly improving engineering design efficiency.

[0006] To achieve the above objectives, the technical solution adopted by the present invention includes the following steps:

[0007] 1. Construct an interface pattern space (M-type and N-type patterns) based on the homogeneous Helmholtz equation.

[0008] 2. Perform a full-wave solution on the platform and project its external scattering field onto the interface mode space to form the platform response operator;

[0009] 3. Perform full-wave solution for the antenna and construct an antenna holographic surrogate operator;

[0010] 4. Define the coupling relationship between the platform and the antenna based on the interface pattern;

[0011] 5. Solve for the radiation and scattering characteristics of the combined system in the interface pattern space.

[0012] The detailed design of this invention is as follows:

[0013] 1. Construction of the interface pattern space

[0014] Both the platform's outer domain and the antenna's outer domain satisfy the homogeneous Helmholtz equation:

[0015] ,

[0016] This invention selects two linearly independent vector modes from its radial eigenvalue family:

[0017] , ,

[0018] Where p and q are model indices describing order and directional characteristics.

[0019] The M-type and N-type modes constitute a finite-dimensional interface mode space, which is used to express the external electromagnetic behavior of the platform and antenna.

[0020] 2. Construction of Platform External Domain Response Operator

[0021] Discretizing the platform surface using the method of moments yields the platform impedance equation:

[0022] ,

[0023] in It is the impedance of the platform. It is the plateau current. The platform's excitation voltage projects the scattered field generated by the platform onto the interface mode space, yielding the mode coefficients:

[0024] ,

[0025] in The mapping matrix from the platform surface current to the mode space is given by:

[0026]

[0027] definition.

[0028] The platform external domain response operator is defined as follows:

[0029] ,

[0030] Used to map stimuli to the mode coefficient domain.

[0031] 3. Construction of Antenna Holographic Surrogate Operator

[0032] The different modes of antenna surface current are expanded as follows:

[0033] ,

[0034] Obtained via MoM:

[0035] ,

[0036] in It is the impedance of the antenna. It is the current on the antenna. It is a projection matrix that projects the current onto the interface mode space, resulting in:

[0037] ,

[0038] Define the antenna proxy operator as:

[0039] .

[0040] 4. Platform Antenna Interface Coupling Operator

[0041] The platform and antenna share the same set of M / N modes at the interface. Therefore, their interaction can be described by a linear relationship between the mode coefficients.

[0042] This invention establishes an interface coupling operator C, whose matrix elements are determined by the mutual projection of patterns on the interface region:

[0043] .

[0044] The mode effect applied by the platform to the antenna is as follows:

[0045] ,

[0046] The mode of antenna application to the platform is as follows:

[0047] .

[0048] 5. Platform Antenna Combination Equations

[0049] The interface pattern equation for a combined system can be written as:

[0050] ,

[0051] If the platform has no external incident radiation The final system response is:

[0052] .

[0053] The innovation of this invention lies in:

[0054] By dividing the platform and antenna interface responses into two modules, the system can be built so that when the platform replaces the antenna, only the antenna parameters need to be calculated, without recalculating the relevant parameters of the platform model. This greatly simplifies the electromagnetic solution in engineering applications and enables rapid prediction of the overall performance of different antennas after they are installed on the platform. Attached Figure Description

[0055] Figure 1 This is a flowchart illustrating the technical implementation of a modular analysis method for platform antenna interface response proposed in this invention.

[0056] Figure 2 It is a system that connects a metal plate to a microstrip loop antenna;

[0057] Figure 3 Here is the gain diagram of the system when the microstrip loop antenna is connected at the center of the platform: (a) Simulation results in HFSS (b) Solution results of this invention;

[0058] Figure 4 Here is the gain diagram of the system when the antenna is connected at a position 5mm offset from the center of the platform in the positive X-axis direction: (a) Simulation results in HFSS (b) Solution results of this invention;

[0059] Figure 5 It is a system in which a metal plate is connected to a dipole antenna;

[0060] Figure 6 Gain diagram of the platform antenna system when the antenna is replaced with a dipole antenna: (a) Simulation results in HFSS (b) Solution results of this invention. Detailed Implementation

[0061] To make the objectives, technical solutions, and innovations of this invention clearer, the invention will be further described in detail below with reference to examples and accompanying drawings.

[0062] Example 1: A single solution for the platform response system. Figure 2 Taking the metal flat platform in the middle as an example, Figure 2 The metal plate platform is an Iron metal plate with a length of 200mm, a width of 200mm, and a thickness of 2mm. The antenna is mounted at the center of the plate at a height of 40mm. After performing a MoM solution on the metal plate platform according to the interface modular analysis method of this invention, the platform response operator can be generated. Therefore, it is not necessary to solve the platform model again in subsequent analysis.

[0063] First, both the outer domain of the metal plate platform and the outer domain of the antenna satisfy the homogeneous Helmholtz equation:

[0064] .

[0065] This invention selects two linearly independent vector modes from its radial eigenvalue family: , Where p and q are mode indices describing order and directional characteristics. The M-type and N-type modes constitute a finite-dimensional interface mode space, used to express the external electromagnetic behavior of the metal plate and antenna.

[0066] The surface of the metal plate platform is discretized using the method of moments to obtain the platform impedance equation. Then, the scattered field generated by the metal plate platform is projected onto the interface mode space to obtain the mode coefficients. The specific solution formula is as follows:

[0067] ,

[0068] in This is the mapping matrix from the platform surface current to the mode space.

[0069] Ultimately, the platform's external domain response operator can be obtained: , The excitation can be mapped to the mode coefficient domain, so that the platform model will not need to be solved again when the antenna is replaced or adjusted later. Figure 3 Is it using HFSS? Figure 2 The gain diagram obtained by solving the medium platform antenna system and the system gain diagram obtained by solving using this invention show that the results obtained by this method are almost identical to those obtained in HFSS, which proves the feasibility of this method.

[0070] Example 2: Antenna Position Adjustment

[0071] In this invention, the change in the position of the same antenna when it is reinstalled on the platform only affects the projection matrix. The phase distribution does not require resolving the platform MoM model, meaning the platform external domain response operator in this invention is unaffected by the antenna installation location. Figure 2 Taking the metal plate platform and antenna system as an example, the antenna is moved 5mm from the center of the platform in the x-axis direction. Figure 4 As can be seen from the system gain comparison diagram, the results obtained by the present invention through the rapid solution of the antenna surrogate operator are very close to the results of HFSS simulation. Furthermore, reducing one solution platform significantly reduces the workload and solution time of the solution system. Table 1 shows the solution time of the model in the embodiment using HFSS simulation and the present invention, achieved with the same equipment. The antenna surrogate operator in the present invention can be solved using a unified algorithm. The specific algorithm flow is as follows.

[0072] First, the surface current of the antenna Expanded to:

[0073] ,

[0074] Obtained via MoM:

[0075] ,

[0076] Projecting the current into the interface pattern space, we get:

[0077] ,

[0078] The antenna surrogate operator is defined as follows:

[0079] .

[0080] Example 3: (and so on) Figure 5 In this embodiment, the antenna in Embodiment 1 is replaced with a dipole antenna, while the platform remains unchanged. Figure 6 The graph shows a comparison between the gain of the system solved by this invention and the gain solved in HFSS when the dipole antenna is replaced on the flat panel. It can be seen that the results of this invention are almost identical to those in HFSS, ensuring the correctness of the solution and further verifying the reliability of the algorithm. Similarly, in Example 2, when using this invention to solve the platform antenna system, changing different antennas only requires solving the antenna surrogate operator again, shortening the solution time. Table 1 shows that by modularizing the system analysis, this invention can reduce the solution to the platform when adjusting the antenna, effectively improving the solution time for the platform antenna system.

[0081] Table 1. HFSS Simulation and Solution Time of this Invention

[0082]

[0083] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A modular analysis method for platform antenna interface response, comprising: Step 1: Construct an interface mode space composed of M-type and N-type eigenmodes based on the homogeneous Helmholtz equation; Step 2: Perform a full-wave solution on the platform and map its external domain response to the interface mode space to obtain the platform response operator; Step 3: Solve for the surface current of the antenna and construct the antenna holographic surrogate operator; Step 4: Construct the platform antenna interface coupling operator based on the mutual projection relationship of the interface pattern; Step 5: Combine the response of the platform and antenna in the interface mode space to obtain the radiation and scattering characteristics of the combined system.

2. The method according to claim 1, wherein the platform response operator is: ， in Let be the mapping matrix from the platform surface current to the mode space. It is the impedance of the platform.

3. The method according to claim 1, wherein the antenna proxy operator is: ， in It is the mapping matrix from the antenna surface current to the mode space. It is the impedance of the antenna. It is a projection matrix.

4. The method according to claim 1, wherein the matrix elements of the interface coupling operator are the projection integrals between interface modes.

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