Offset Antenna Efficiency Calculator

Updated 05 February 2018

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Antenna Height & Width m X m
Antenna Gain dB
@ Frequency MHz
Antenna Efficiency %
Offset Angle
Satellites elevation angle ( use the lookangles calculator)
Expected measured antenna tilt

The calculator is valid only for elliptic Offset antennas with circular apperature (height greater than width). Antennas like Torodial,Raven and other specially designed mulitfocus offset antennas is NOT supported by this calculator. The calculation has been tested on a Fibo 135cm X 120cm antenna and it gives a good result. The default figures is for the Fibo 120cm (apperature diameter).

See this figure

Calculation is based on an article in the Norwegian TELEKTRONIKK Issue 1 1988. The article is in Norwegian only and can be found here(1.7MByte Adobe PDF)

More Telektronikk issues can be found on and

2016 Jens T. Satre