Jerry Martes wrote:

Bill

How does a person measure the gain of an antenna?

Jerry


In the olden days, 1985, on an outdoor range, we would calculate the
gain from measuring the 1/2 power points on an antenna range at 1000
wavelengths minimum between antennas and find the 1/2 power [-3 dB]
angles in the horizontal and vertical planes. [Note C-Band and S-Band]

Knowing the angles the 'Gain' is calculated by dividing 41259 by the
product of the horizontal and vertical angles corresponding to the 1/2
power point. [Note: 41259 is the surface of the sphere measured in
square steradians.]

On the indoor anechoic chamber we measured the input power at the feed
point through a -10 dB splitter and the radiated power density at a
target point in the far wall. Then ran the basic calculation.
[Classified Military Program]

Aligning those 12 foot diameter dishes inside the anechoic chamber was
'fun'.

Even after managing two antenna ranges and being party to 'antenna gain'
measurements for more than 10 years of my professional life, I still
have fun touting that antennas have 'No Gain'.