The function “customAntennaMesh” is part of the Antenna Toolbox in MATLAB and is used to define custom antenna geometries using a mesh representation. It's ideal for designing complex antenna shapes that are not available in the toolbox's predefined options.
It needs 2 inputs:
1. Points: It is a “2 × N” or “3 × N” matrix representing Cartesian coordinates in meters, where “N” is the number of points.
- 2 × N matrix - Defines points in 2D (x, y).
- 3 × N matrix - Defines points in 3D (x, y, z), but “z” must be constant or zero.
2. Triangles: It is a “4 × M” matrix, where “M” is the number of triangles. The first three rows define triangle vertices (indices of points), and the fourth row assigns a domain number.
Refer the below link for “customAntennaMesh” function:
Here is an example code for sinuous antenna mesh:
clc; clear; close all;
% Define parameters for sinuous curve
a = 0.1; % Scaling factor (assumed)
b = 0.2; % Growth rate (assumed)
t = linspace(0, 4*pi, 50); % Angle range for the sinuous shape
% Compute Cartesian coordinates (r(t) = a * exp(b * t))
x = (a * exp(b * t)) .* cos(t);
y = (a * exp(b * t)) .* sin(t);
z = zeros(size(x)); % Keep z = 0 for a 2D structure
% Create the points matrix (3 x N)
points = [x; y; z];
A sinuous antenna has a spiral-like shape, which makes it difficult to manually define the triangular mesh. The function “delaunayTriangulation(x, y)” automatically computes a triangular mesh connecting the given 2D points.
The output is a connectivity list, which provides the indices of three points forming each triangle. “dt.ConnectivityList” provides triangle indices based on the computed points.
Refer the below link for “delaunayTriangulation” function:
% Use Delaunay triangulation for correct connectivity
dt = delaunayTriangulation(x', y');
triangles = [dt.ConnectivityList'; ones(1, size(dt.ConnectivityList, 1))];
% Create and visualize the custom antenna mesh
mesh = customAntennaMesh(points, triangles);
figure;
show(mesh); % Display mesh without additional arguments
title('Sinuous Antenna Mesh');
A possible workaround is to use “patch()” function for visualization while keeping “delaunayTriangulation()” to generate the mesh.
Refer the below link for “patch()” function:
I hope this helps!
