Antenna beamwidth calculator

Enter the diameter of your parabolic dish in m (metres) and the operating frequency in GHz (Gigahertz)

A typical VSAT is 1.2m diameter and transmits at 14 - 14.5 GHz

The calculation results are:

  • The total side to side beamwidth of the antenna main beam.
  • Half the side to side beamwidth, if you are concerned to determine the offset angle from the beam centre.
  • The on-axis gain, relative to an isotropic omni-directional antenna.

The results are approximate beyond the -3 dB contour.
Maximum main beam gain assumes an aperture efficiency of 0.65
The shape of the main beam assumes that the edge illumination of the dish is -10 dB down.

Any problems or comments, please e-mail me Eric Johnston   This calculator is copyright © 2007 Satellite Signals Ltd

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Sub reflector adjustments 

Original : 10 Oct 2007, amended 16 Dec 2007

Diameter of your satellite dish

Frequency

metres GHz

dB contour
down
Full beamwidth
degrees  
Half beamwidth
degrees  
Gain
dBi
0 0 0
0.25
0.5
1
2
3
4
5
6
10
15