A method for calculating the propagation constant of a two-dimensional orthogonal leaky-wave antenna

Abstract

The invention discloses a method for calculating the propagation constant of a leaky wave antenna applied to a two-dimensional orthogonal structure. The method uses a macrocell method originally used for a one-dimensional periodic leaky wave antenna and re-optimizes its calculation parameters to obtain an improved macrocell method applied to a two-dimensional orthogonal patch structure. Then, the scattering parameters of the two-dimensional orthogonal patch leaky wave antenna at various angles are measured through a dual port. Finally, the propagation constants at various angles are calculated through the measured scattering parameters, so that the propagation constant curves at various angles of the antenna can be accurately obtained. Through the curves at multiple angles, the complete propagation characteristics of the target antenna can be obtained.

Description

Technical Field

[0001] The present invention relates to the field of radio, and more particularly to a method for calculating a propagation constant of a leaky wave antenna with a two-dimensional orthogonal structure. Background Art

[0002] Since leaky wave antennas have frequency scanning capabilities, they are widely used in conformal antennas, high-resolution radars, and satellite communications. Unlike resonant antennas, when leaky wave antennas operate in the leakage wave frequency band, the antenna power will be radiated along its long side in the form of space waves. Common leaky wave antennas are one-dimensional periodic patch structures, and their radiation beams have the ability to perform frequency scanning on the same plane. Common two-dimensional leaky wave antennas include bull's eye type, radial type, metal array type, etc. Common one-dimensional leaky wave antenna radiation propagation constants or antenna radiation analysis methods include: eigenmode method, lateral cavity membrane method, deconvolution method, unit cell method, macrocell method, and reciprocity spectral domain periodic method, periodic spectral domain impedance method, full-wave analysis method, etc. for two-dimensional leaky wave antennas. However, the propagation constants of existing two-dimensional orthogonal leaky wave antennas are complex to calculate, not universal, and not simple. Summary of the invention

[0003] The purpose of the present invention is to solve the defects of the existing two-dimensional orthogonal leaky wave antenna, such as complex calculation of propagation constant, limited versatility and inconvenience, and to propose a method for calculating the propagation constant of a leaky wave antenna with a two-dimensional orthogonal structure.

[0004] In order to achieve the above invention purpose, the technical solution adopted is:

[0005] A method for calculating the propagation constant of a leaky wave antenna with a two-dimensional orthogonal structure, comprising the following steps:

[0006] S1: The macrocell method originally used for one-dimensional periodic leaky wave antennas is used to optimize its calculation parameters, and an improved macrocell method for two-dimensional orthogonal patch structures is obtained;

[0007] S2: measuring the scattering parameters of the two-dimensional orthogonal patch leaky-wave antenna at each angle through a dual port;

[0008] S3: Calculate the propagation constants at various angles using the measured scattering parameters.

[0009] Preferably, the two-dimensional orthogonal patch structure comprises an orthogonal metal patch radiator, a metal floor and a feeding connector.

[0010] Preferably, the measuring of the scattering parameters of the two-dimensional orthogonal patch leaky-wave antenna at various angles through a dual port includes obtaining the scattering parameters of the antenna through a dual port located at the center and edge of the antenna, including the real and imaginary values ​​of S11, S12, S21, and S22.

[0011] Preferably, the re-optimization of the calculation parameters includes re-equivalently calculating the periodic unit spacing and the number of periodic units in the calculation parameters.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] The present invention proposes a method for calculating the propagation constant of a leaky wave antenna with a two-dimensional orthogonal structure. Under the condition that the basic calculation method remains unchanged, a practical formula method for applying the macro cell method to the two-dimensional orthogonal leaky wave antenna is obtained by performing specific operations corresponding to different angles of the antenna and optimizing the structural parameters at each angle. The propagation constant curve at each angle of the antenna can be accurately obtained, and the complete propagation characteristics of the target antenna can be obtained through the curves at multiple angles. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the steps of the present invention;

[0015] Figure 2 is a basic schematic diagram of a two-dimensional orthogonal patch leaky wave antenna of the present invention, wherein (1) is an arbitrary periodic patch structure, and (2) is orthogonal coupling between periods;

[0016] Figure 3 It is a basic structural diagram of the two-dimensional orthogonal patch leaky wave antenna of the present invention;

[0017] Figure 4 It is a top view of the two-dimensional orthogonal patch leaky wave antenna of the present invention, wherein (3) is a metal patch of an orthogonal structure, and (4) is a dielectric substrate of the antenna;

[0018] Figure 5 It is a side view of the two-dimensional orthogonal patch leaky wave antenna of the present invention, wherein (5) is the antenna metal floor, and (6) is the coaxial feed head;

[0019] Figure 6 A schematic diagram of the present invention of setting coaxial dual ports at the center and edge of the antenna at the desired angle;

[0020] Figure 7 This is a comparison chart between the macrocell method calculated using the simulation S11 results and the simulation results. DETAILED DESCRIPTION

[0021] The drawings are for illustrative purposes only and should not be construed as limiting the present patent;

[0022] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0023] Example 1

[0024] A method for calculating the propagation constant of a leaky-wave antenna with a two-dimensional orthogonal structure, see Figure 1 , including the following steps:

[0025] S1: The macrocell method originally used for one-dimensional periodic leaky wave antennas is used to optimize its calculation parameters, and an improved macrocell method for two-dimensional orthogonal patch structures is obtained;

[0026] S2: measuring the scattering parameters of the two-dimensional orthogonal patch leaky-wave antenna at each angle through a dual port;

[0027] S3: Calculate the propagation constants at various angles using the measured scattering parameters.

[0028] In this embodiment, the two-dimensional orthogonal patch structure includes an orthogonal metal patch radiator 3, a metal floor 5 and a feed connector 6. Figures 2 to 5 .

[0029] In this embodiment, the scattering parameters of the two-dimensional orthogonal patch leaky wave antenna at each angle are measured by dual ports, including the real and imaginary values ​​of S11, S12, S21, and S22, respectively. Figure 6 .

[0030] In this embodiment, the re-optimization of the calculation parameters includes re-equivalently calculating the periodic unit spacing and the number of periodic units in the calculation parameters.

[0031] In this embodiment, according to Floquet's theorem and the macrocell method, the propagation constant (wave number) of the nth harmonic calculated by the macrocell method for the one-dimensional periodic leaky wave antenna is:

[0032]

[0033] where k zn is the propagation constant (wave number) of the nth harmonic, λ N,n The eigenvalue of the transmission matrix (T matrix) between the two ports, N is the number of periodic units, p is the periodic unit spacing, and m is the phase difference between the two ports.

[0034] The calculation formula is optimized as follows:

[0035]

[0036] Where p' is the optimized periodic unit spacing, and p' is defined as follows:

[0037]

[0038] According to different angles, two ports are set at the center and edge of the angle, respectively, e.g. Figure 6 As shown in the figure, the scattering parameter matrix of the antenna at each angle is directly obtained by HFSS simulation or network analyzer, and the scattering parameters are mapped to the transmission matrix and calculated by the macro cell method to obtain the corresponding propagation constant curve. The complete propagation characteristics of the antenna can be obtained by integrating multiple angle curves. Figure 7 It can be concluded that this method is effective and feasible.

[0039] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for calculating the propagation constant of a leaky wave antenna with a two-dimensional orthogonal patch structure, characterized in that: The following steps are involved: S1: The macrocell method originally used for one-dimensional periodic leaky-wave antennas is used to optimize its calculation parameters, and an improved macrocell method applied to leaky-wave antennas with two-dimensional orthogonal patch structures is obtained; S2: measuring the scattering parameters of the leaky wave antenna of the two-dimensional orthogonal patch structure at various angles through a dual port; S3: Calculate the propagation constant at each angle using the measured scattering parameters; The re-optimization of the calculation parameters includes re-equivalently calculating the periodic unit spacing and the number of periodic units in the calculation parameters; The dual-port measurement of the scattering parameters of the leaky-wave antenna of the two-dimensional orthogonal patch structure at various angles includes obtaining the scattering parameters of the antenna through the dual ports located at the center and edge of the antenna, including the real and imaginary values ​​of S11, S12, S21, and S22.

2. The method for calculating the propagation constant of a leaky wave antenna with a two-dimensional orthogonal patch structure according to claim 1, characterized in that: The two-dimensional orthogonal patch structure comprises an orthogonal metal patch radiator (3), a metal floor (5) and a feeding connector (6).

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