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 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.

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