Designing a Microstrip Array Antenna Using Genetic Algorithm

Hi, I've recently got a project to design a microstrip array antenna using Genetic Algorithm on Matlab. The odd part is how our university failed to give us any tutorials on Matlab beforehand. Can anyone help me out as to how i'm supposed to get the design parameters using MATLAB, or if you have any similar coding that would be appreciated..thanks a lot!

Answer 1

[Anshuman]

Here is an example to help you get started. This example assumes you are optimizing the length and width of the patches in a microstrip array.

First you have to define the Objective Function:

function fitness = antenna_fitness(params)
    % params: [length, width]
    length = params(1);
    width = params(2);
    
    % Simulate the antenna (this is a placeholder for actual simulation code)
    % [gain, return_loss] = simulate_antenna(length, width);
    
    % For demonstration, let's assume the following dummy values
    gain = 10 * (1 - exp(-0.1 * (length - 5)^2 - 0.1 * (width - 5)^2));
    return_loss = 20 * exp(-0.1 * (length - 5)^2 - 0.1 * (width - 5)^2);
    
    % Objective: Maximize gain and minimize return loss
    fitness = gain - return_loss;
end

Now you have to set up and run the genetic algorithm:

% Define the number of variables
nvars = 2;

% Define the bounds for the variables
lb = [1, 1]; % lower bounds
ub = [10, 10]; % upper bounds

% Set GA options
options = optimoptions('ga', ...
    'PopulationSize', 50, ...
    'MaxGenerations', 100, ...
    'CrossoverFraction', 0.8, ...
    'MutationRate', 0.1, ...
    'Display', 'iter');

% Run the Genetic Algorithm
[best_params, best_fitness] = ga(@antenna_fitness, nvars, [], [], [], [], lb, ub, [], options);

% Display the best parameters
disp('Best Parameters:');
disp(['Length: ', num2str(best_params(1))]);
disp(['Width: ', num2str(best_params(2))]);

% Display the best fitness
disp(['Best Fitness: ', num2str(best_fitness)]);

You can refer to the following MathWorks documentation for more details:

Genetic Algorithm - MATLAB & Simulink - MathWorks India

Genetic Algorithm Options - MATLAB & Simulink - MathWorks India

Hope it helps!