MATLAB Code for Calculating Electromagnetic Fields at Double Frequency

Certainly! Here's an example MATLAB code to calculate the electromagnetic fields at double the fundamental frequency, assuming the initial fields at the fundamental frequency and the material properties are known:

%% Constants and material properties
c = 3e8; % Speed of light (m/s)
f = 1e9; % Fundamental frequency (Hz)
wavelength = c/f; % Wavelength at fundamental frequency (m)
epsilon_0 = 8.854e-12; % Permittivity of free space (F/m)

epsilon_r = 2; % Relative permittivity of the material (dimensionless)
mu_r = 1; % Relative permeability of the material (dimensionless)

%% Calculation
f_double = 2*f; % Double frequency (Hz)
wavelength_double = c/f_double; % Wavelength at double frequency (m)

k = 2*pi/wavelength; % Wave number at fundamental frequency (rad/m)
k_double = 2*pi/wavelength_double; % Wave number at double frequency (rad/m)

% Electric field at double frequency
E_double = 1; % Initial electric field amplitude at fundamental frequency (V/m)
E_double = E_double * exp(1i*k_double*z); % Propagation in z-direction

% Magnetic field at double frequency
H_double = E_double / sqrt(epsilon_r*mu_r); % Magnetic field amplitude at double frequency (A/m)

% Electric field at fundamental frequency
E = E_double * exp(-1i*k*z); % Electric field amplitude at fundamental frequency (V/m)

% Magnetic field at fundamental frequency
H = E / sqrt(epsilon_r*mu_r); % Magnetic field amplitude at fundamental frequency (A/m)

In this code, the initial electric field amplitude at the fundamental frequency is given by 'E_double'. The propagation in the z-direction is considered using the exponential term 'exp(1ik_doublez)'. The electric and magnetic fields at the fundamental frequency are then calculated based on the relative permittivity and permeability of the material.

Note: This code assumes a uniform medium in the z-direction. If your scenario involves a more complex geometry or boundary conditions, additional calculations or modifications may be required.