Plot E-field pattern

Greetings,

I can use some help in plottng an E-field pattern for an array of nfinitesimal dipole elements placed along the z-axis. It is

E(θ) = sin(θ) (z-1)(z^3 - 1)

d = lambda/2

Where z=e^(jkdcosθ ), the far-field pattern of an infinitesimal dipole antenna is approximated with sin(θ), and β = 0.

I need to plot |E(θ)|^2 for θ є [0degrees,180degrees] in linear and dB scale

I have no problems doing the analytical calculations, but I admit my coding skills need practice. If anyone can write up the code or at lleast write up a template. I am a grad student trying to beef up my Matlab skills. Thank you!

Answer 1

[Chaitanya]

Hi @Jose Iglesias,

Here's a template you can use:

% Constants
lambda = 1; % Wavelength
d = lambda / 2; % Distance between elements

% Define the range of theta values
theta = linspace(0, pi, 100);

% Calculate the E-field pattern
z = exp(1i * k * d * cos(theta));
E = sin(theta) .* (z - 1) .* (z.^3 - 1);

% Calculate the magnitude squared of E
E_squared = abs(E).^2;

% Plot the E-field pattern in linear scale
figure;
plot(theta, E_squared);
xlabel('θ (radians)');
ylabel('|E(θ)|^2');
title('E-field Pattern (Linear Scale)');

% Plot the E-field pattern in dB scale
figure;
plot(theta, 10*log10(E_squared));
xlabel('θ (radians)');
ylabel('|E(θ)|^2 (dB)');
title('E-field Pattern (dB Scale)');

In this code, you can adjust the value of lambda to represent the wavelength of the signal, and k is the wave number. The d variable represents the distance between the dipole elements.

The code calculates the E-field pattern for the given range of theta values using the provided formula. Then, it calculates the magnitude squared of E and stores it in the E_squared variable.

Finally, the code plots the E-field pattern in both linear and dB scales using the plot function. The xlabel, ylabel, and title functions are used to label the axes and provide a title for each plot.

You can run this code in MATLAB to visualize the E-field pattern in both linear and dB scales for the given range of theta values.

Hope this helps!