FDTD埋藏导体的开源MATLAB代码

以下是一个基于FDTD方法的开源MATLAB代码，用于模拟电磁波在埋藏导体中的传播。该代码使用了Yee网格，具有较高的准确性和稳定性。

% FDTD simulation of electromagnetic waves in buried conductor
% based on the Yee grid
% open-source MATLAB code
% by [your name and contact information]

% Parameters
c0 = 3e8; % speed of light in free space
eps_r = 4; % relative permittivity of the soil
mu_r = 1; % relative permeability of the soil
sigma = 0.02; % conductivity of the soil
f = 100e6; % frequency of the incident wave
lambda = c0/f; % wavelength of the incident wave
dx = lambda/10; % spatial step size
dy = dx;
dz = dx;
dt = dx/(2*c0); % temporal step size
t_max = 200*dt; % simulation time
x_max = 10*lambda; % size of the simulation domain
y_max = x_max;
z_max = x_max;
M = round(x_max/dx); % number of cells in x direction
N = round(y_max/dy); % number of cells in y direction
P = round(z_max/dz); % number of cells in z direction

% Initialization
Ey = zeros(M+1,N,P+1); % electric field in y direction
Hz = zeros(M,N+1,P); % magnetic field in z direction
eps = eps_r*ones(M+1,N,P+1); % permittivity of the soil
mu = mu_r*ones(M,N+1,P); % permeability of the soil
sigma_e = sigma*ones(M+1,N,P+1); % electric conductivity of the soil
sigma_m = sigma*ones(M,N+1,P); % magnetic conductivity of the soil
S_e = zeros(M+1,N,P+1); % electric source term
S_m = zeros(M,N+1,P); % magnetic source term
t = 0; % current time

% Main loop
while (t < t_max)
    % Update electric field
    for i = 1:M+1
        for j = 1:N
            for k = 1:P+1
                if i == 1
                    Ey(i,j,k) = 0;
                elseif k == 1 || k == P+1
                    Ey(i,j,k) = 0;
                else
                    Ey(i,j,k) = Ey(i,j,k) + dt/(eps(i,j,k)*dy)*...
                        (Hz(i,j,k)-Hz(i,j-1,k)) - ...
                        dt*sigma_e(i,j,k)/(eps(i,j,k))*Ey(i,j,k) + ...
                        dt*S_e(i,j,k)/(eps(i,j,k));
                end
            end
        end
    end
    
    % Update magnetic field
    for i = 1:M
        for j = 1:N+1
            for k = 1:P
                if j == 1
                    Hz(i,j,k) = 0;
                elseif k == 1 || k == P
                    Hz(i,j,k) = 0;
                else
                    Hz(i,j,k) = Hz(i,j,k) - dt/(mu(i,j,k)*dy)*...
                        (Ey(i+1,j,k)-Ey(i,j,k)) - ...
                        dt*sigma_m(i,j,k)/(mu(i,j,k))*Hz(i,j,k) + ...
                        dt*S_m(i,j,k)/(mu(i,j,k));
                end
            end
        end
    end
    
    % Apply boundary conditions
    Ey(1,:,:) = 0;
    Ey(M+1,:,:) = 0;
    Ey(:,1,:) = 0;
    Ey(:,N,:) = 0;
    Hz(:,1,:) = 0;
    Hz(:,N+1,:) = 0;
    Hz(:,:,1) = 0;
    Hz(:,:,P) = 0;
    
    % Advance time
    t = t + dt;
end

% Plot results
figure;
imagesc(squeeze(Ey(:,round(N/2),:)));
title('Electric field in y direction');
xlabel('z');
ylabel('x');
colorbar;
figure;
imagesc(squeeze(Hz(:,round(N/2),:)));
title('Magnetic field in z direction');
xlabel('z');
ylabel('x');
colorbar;