Calculating Beamwidths for Dipole Antenna

Hello,

I want to calculate the linear dipole antenna 3-dB beamwidth from the polar plot shown below

My code

th = 0:001:2*pi;

rounded_pattern = round(pattern(th),4);
e = find(rounded_pattern == 0.7071)
HPBW = th(e(2)) - th((1));

The concept here is to get the first and the second angles that satisfy 0.7071 of the peak and substract them. But the results are not as I intended.

Any ideas?

Answer 1

[Sourabh Joshi]

I tried executing your code but received an error.

Error using pattern

Conversion to pattern from double is not possible.

I feel it is possible some part of the code is missing or not attached with the question.

However, you may use the Antenna Toolbox to calculate the HPBW (Half Power Beamwidths) of an antenna and the following code will generate the pattern of the dipole antenna and if you Right-Click on the generated figure and select Measurements --> Antenna Metrics from the menu, it will plot the Half Power Beamwidths on the graph. The plot is interactive and you can move the markers to calculate the HPBW for the other lobes as well.

ant = dipole
ant = design(ant,1e9);
figure,pattern(ant,8e9);
figure,patternElevation(ant,8e9,0);

Right-Click on the generated figure and select Measurements-->Antenna Metrics from the menu