Import MSI antenna file into a custom antenna element

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Hello i've downloaded a correct MSI radiation pattern file. I've imported it using MSI read, i'm able to visualize to azimuth and elevation cut patterns.
i want to use its radiation pattern and create a custom antenna element using phased.CustomAntennaElement
the issue is when i try using phased.CustomAntennaElement arguments 'HorizontalMagnitudePattern', and 'VerticalMagnitudePattern' i get a size error since the vertical and horizontal magnitute patterns ive imported from the msi files have 360x1 size instead the arguments of the custom antenna expects 181x361?
"
Error using phased.internal.AbstractElement (line 25)
Expected HorizontalMagnitudePattern to be of size 181x361, but it is of size 360x1.
"
here is my code
clear;clc;
azang = [-180:180];
elang = [-90:90];
[Horizontal,Vertical,Optional] = msiread('Kathrein\80010652_2655_x_co_p45_08t_rs.msi');
phasepattern = zeros(361);
antena = phased.CustomAntennaElement('AzimuthAngles',azang, ...
'ElevationAngles',elang,'SpecifyPolarizationPattern',true,...
'HorizontalMagnitudePattern', Horizontal.Magnitude, ...
'VerticalMagnitudePattern',Vertical.Magnitude,'PhasePattern',phasepattern);
pattern(antena,2.655e9,[-180:180],[-180:180],'CoordinateSystem',...
'Polar','Type','powerdb')

Answers (1)

Joshua Jones
Joshua Jones on 17 Jun 2021
Edited: Joshua Jones on 17 Jun 2021
Here's what I did. You have to match the # of angles with the # of magnitude points. *Edit: This isn't right, it's mapping the values starting at 0:360 for the MSI import to either -180:180 or -90:90. I'll keep tinkering and will update the code when I figure it out. Sorry
clear all;
close all;
clc
%Import MSI data
[Horizontal,Vertical,Optional] = msiread('KRE1012249_1_P+45_1990_PWR_08T.msi');
%% Define Variables
fc = Optional.frequency;
el_ang = -90:90;
el_mag = Vertical.Magnitude;
el_mag = [el_mag; el_mag(1)]; %repeat first value
az_ang = -180:180;
az_mag = Horizontal.Magnitude;
az_mag = [az_mag; az_mag(1)]; %repeat first value
%% Create Phase pattern
az_phase = zeros(181,361);
el_phase = zeros(181,361);
%% Transpose and Convert Magnitude Patterns
az_mag_matrix = repmat(az_mag', 181, 1);
el_mag_matrix = repmat(el_mag', 181, 1);
%% Build Custom Antenna from MSI data
antenna = phased.CustomAntennaElement(...
'AzimuthAngles', az_ang, ...
'ElevationAngles', el_ang, ...
'SpecifyPolarizationPattern', true, ...
'HorizontalMagnitudePattern', az_mag_matrix, ...
'VerticalMagnitudePattern', el_mag_matrix, ...
'HorizontalPhasePattern', az_phase, ...
'VerticalPhasePattern', el_phase);
%% Plots for confirmation
% figure
% subplot(1,2,1)
% Pel = polarpattern(Vertical.Elevation, Vertical.Magnitude);
% subplot(1,2,2)
% Paz = polarpattern(Horizontal.Azimuth, Horizontal.Magnitude);
%
% subplot(1,3,3)
figure
pattern(antenna, fc, ...
'CoordinateSystem', 'polar', ...
'Type', 'powerdb')
  2 Comments
Adam Danz
Adam Danz on 17 Jun 2021
Welcome to the forum. Please edit your answer and use the code/text toggle in rich text editor to format your code.
jim wild
jim wild on 19 Jun 2021
Hi joshua thanks for your reply i tried your code ut gave me some ideas ill try them later
altough the topic is old im still very interested in this case
thanks BR

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