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beamwidth

Beamwidth of antenna

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Syntax

beamwidth(object,frequency,azimuth,elevation)
bw = beamwidth(object,frequency,azimuth,elevation,dBdown)
[bw,angles] = beamwidth(____)

Description

beamwidth(object,frequency,azimuth,elevation) plots the beamwidth of the specified antenna or array at the specified frequency. The beamwidth is the angular separation at which the magnitude of the directivity pattern decreases by a certain value from the peak of the main beam. The directivity decreases in the direction specified by azimuth and elevation angles of the antenna.

Note

  • beamwidth plots only one beamwidth for symmetrical patterns.

  • beamwidth might not interpret partial angle data well.

example

bw = beamwidth(object,frequency,azimuth,elevation,dBdown) returns the beamwidth of an antenna or array at a specified dBdown value from the peak of the main beam radiation pattern.

[bw,angles] = beamwidth(____) returns the beamwidth and angles (points in a plane) using any input arguments from previous syntaxes.

example

Examples

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Open Live Script

Plot the beamwidth for a dipole antenna at azimuth=0 and elevation=1:1:360 (x-z plane)

d  = dipole; 
beamwidth(d,70e6,0,1:1:360);

Figure contains an axes object and an object of type uicontrol. The hidden axes object contains 2 objects of type patch, line.

Open Live Script

Calculate the beamwidth of a helix antenna and the angles of the beamwidth. The antenna has an azimuth angle of 1:1:360 degrees, an elevation angle of 0 degrees on the X-Y plane, and a dB down value of 5 dB.

hx = helix;
[bw,angles] = beamwidth(hx,2e9,1:1:360,0,5)
bw = 
141

angles = 1×2

   146   287
Open Live Script

Create a fractalGasket antenna object.

fg = fractalGasket(NumIterations=4, TiltAxis=[0 1 0], Tilt=90);

Calculate beamwidth and angle of a fractalGasket.

[bw,ang] = beamwidth(fg, 1.3e9, 0, 0:1:360)
bw = 2×1

   34.0000
   34.0000


ang = 2×2

    25    59
   121   155

Plot beamwidth. 

beamwidth(fg, 1.3e9, 0, 0:1:360)

Figure contains an axes object and an object of type uicontrol. The hidden axes object contains 2 objects of type patch, line.

Plot Second Beamwidth Solution

Get the polarpattern handle.

P = polarpattern("gco");

Hide the beamwidth span and remove the cursor C1 and C2. All the cursors can also be removed using the function removeCursors.

showSpan(P,0);              
removeCursors(P,1);          
removeCursors(P,2);

Add the cursors at other side of the plot and second beamwidth solution is displayed.

addCursor(P,ang(2,:));      
showSpan(P,1);

Figure contains an axes object and an object of type uicontrol. The hidden axes object contains 2 objects of type patch, line.

Input Arguments

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Antenna, array, custom mesh, custom geometry, or custom antenna, specified as either of these:

Frequency used to calculate beamwidth, specified as a scalar in Hz.

Example: 70e6

Data Types: double

Azimuth angles used to calculate the beamwidth of the antenna or array, specified as a scalar or vector in degrees. If the elevation angle is specified as a vector, then the azimuth angle must be a scalar.

Example: 3

Data Types: double

Elevation angle used to calculate the beamwidth of the antenna or array, specified as a scalar or vector in degrees. If the azimuth angle is specified as a vector, then the elevation angle must be a scalar.

Example: 1:1:360

Data Types: double

Power point from peak of main beam of antenna or array, specified as a scalar in dB.

Example: 5

Data Types: double

Output Arguments

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Beamwidth of antenna or array, returned as a scalar in degrees or a 2-by-1 vector in degrees.

Example: 141

Data Types: double

Angular points encompassing the main beam on the azimuth or elevation pattern plot used to measure beamwidth, returned as a vector in degrees.

Example: [146 287]

Data Types: double

Version History

Introduced in R2015a

See Also

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