Analyze Cylindrical Reflector Antenna with Horn Array Feed
This example shows how to analyze an antenna consisting of a cylindrical reflector with a linear array of horns.
Create Horn Antenna
Create a horn antenna resonating at 10 GHz. Set
lambda to the free space wavelength at the design frequency of 10 GHz.
freq = 10e9; lambda = physconst('light')/freq; h = design(horn,10e9); h.FlareWidth = 0.0416; h.FlareLength = 0.0416; h.FlareHeight = 31.8e-3; h.Length = 21e-3; h.FeedOffset(1) = -3.6e-3; figure; show(h)
Plot VSWR and Radiation Pattern of Horn Antenna
Plot the voltage standing wave ratio (VSWR) of the horn antenna over the frequency range of 8.5–12.5 GHz.
range = (0.85:0.01:1.25)*freq; figure; vswr(h,range); ylim([0 5]);
The VSWR of the horn antenna is less than 2 between 8.6–12.2 GHz.
Plot the radiation pattern of the horn antenna.
The directivity of the antenna is 11.4 dB.
Create Linear Array of Horns
Create a linear array of horns. Set the number of elements in the array to 4 and the spacing between the elements to 1.5 times of lambda.
arr = linearArray('Element',h,'NumElements',4); arr.Element.Tilt = -90; arr.Element.TiltAxis = 'Z'; arr.ElementSpacing = 1.5*lambda; figure; show(arr)
Create Cylindrical Reflector with Horn Array
Create a cylindrical reflector with the linear array of horns as the exciter. Tilt the exciter at an angle of 90 degrees along the Z-axis and 70 degrees along the Y-axis.
ref = reflectorCylindrical; ref.GroundPlaneLength = 10.2*lambda; ref.GroundPlaneWidth = 10.3*lambda; ref.Spacing = 8.5*lambda; ref.Tilt = 90; ref.Exciter = arr; ref.Exciter.Tilt = [90 70]; ref.Exciter.TiltAxis = ['Z','Y']; figure; show(ref)
Mesh and Plot Radiation Pattern of Cylindrical Reflector with Horn Array
Mesh the reflector manually with the maximum edge length of
Load the solved reflector file
Plot the radiation pattern.
figure; pattern(ref,freq); view([80 10]);
You can also plot the radiation pattern without using the MAT file, but the
pattern(ref,freq) command takes up to 18 minutes to plot the radiation pattern. To run the
pattern(ref,freq) command, these machine configurations are preferred:
Processor: Intel ® Xeon ® CPU E5-1650 v4 @3.60GHz.
System type: 64-bit operating system.
The directivity of the cylindrical reflector antenna with a horn array feed is 18.7 dB.
 Zhang.R, Z. Xie and Q. Chu. "A New Horn Array Feed for Parabolic Cylindrical Reflector Antenna." 2007 Asia-Pacific Microwave Conference, 2007, pp.1-4. doi: 10.1109/APMC.2007.4555169.