Hi Robert Achatz,
Creating a complete and accurate code for computing the pattern and impedance of a short vertical monopole over lossy ground is a complex task. You would likely need to use numerical methods and have a deep understanding of electromagnetics to implement a full solution.
Here is a simplified outline of steps you might take in MATLAB to model this scenario:
- Define the properties of the monopole and the lossy ground.
- Use an appropriate numerical method, like the Method of Moments, to solve for the current distribution on the monopole.
- Calculate the far-field radiation pattern based on the current distribution.
- Compute the input impedance of the monopole.
Here is a simplified MATLAB script outline to give you an idea of how you might start:
% Define physical constants
epsilon_0 = 8.854187817e-12; % Vacuum permittivity (F/m)
mu_0 = 4*pi*1e-7; % Vacuum permeability (H/m)
c = 1/sqrt(mu_0*epsilon_0); % Speed of light (m/s)
% Define monopole properties
h = 1; % Height of the monopole (m)
f = 10e6; % Operating frequency (Hz)
lambda = c / f; % Wavelength (m)
k = 2*pi / lambda; % Wave number (rad/m)
% Define lossy ground properties
epsilon_r = 15; % Relative permittivity of the ground
sigma = 0.005; % Conductivity of the ground (S/m)
epsilon = epsilon_r * epsilon_0 - 1i*sigma/(2*pi*f); % Complex permittivity
% Define discretization parameters for the monopole (Method of Moments)
N = 100; % Number of segments to divide the monopole into
dz = h / N; % Length of each segment
% (The following steps are placeholders and require the actual numerical
% implementation of the Method of Moments and other calculations.)
% Step 1: Calculate the impedance matrix (Z) for the monopole
Z = zeros(N, N); % Placeholder for the impedance matrix
% Step 2: Calculate the excitation vector (V)
V = zeros(N, 1); % Placeholder for the excitation vector
% Step 3: Solve for the current distribution (I)
I = Z\V; % Placeholder for the current distribution
% Step 4: Calculate the far-field radiation pattern based on I
% (Placeholder for radiation pattern calculation)
% Step 5: Compute the input impedance of the monopole
% (Placeholder for input impedance calculation)
% Visualization and analysis of results
% (Placeholder for plotting and analysis)
I hope this helps!
Best Regards,
Abhishek Chakram
