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Inclined orbit operation.
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Dish interference: Site shielding.
Correcting VSAT dish distortion.
Antenna panel alignment.
Satellite beam design.

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.
  • Antenna gain. dBi means relative to an isotropic omni-directional antenna.
  • The antenna gain shown in top line of the results is the on-axis gain.

The results are increasingly approximate beyond the -3 dB contour. The first null may appear at an angle off the boresight similar the the -3 dB full beamwidth.

Default values:
Maximum main beam gain calculation assumes an efficiency of 0.65
The shape of the main beam assumes parabolic illumination with level at dish edge = -10 dB down.

Diameter of your satellite dish Frequency Efficiency
0.6 to 0.8
metres GHz  

dB contour
down
Full beamwidth
degrees  
Half beamwidth
degrees  
Gain
dBi
0 0 0
0.25
0.5
1
2
3
4
4.5
5
6
7
10
15
Any problems or comments, please e-mail me Eric Johnston
This calculator is copyright 2007 Satellite Signals Ltd

Original : 10 Oct 2007.   Amended 9 April 2012 to include the possibility of altering the efficiency, in the range 0.6 to 0.8

Page last updated 10 Oct July 2014