Dears,
merry Chrismas,
What is the different between IEEE (Gain) and Realized Gain of an antenna in CST?
Sincerely,
Hayder S. Ahmed
Hi,
incident power (Pinc) = 1W
accepted power (Pacc) = Pinc * (1 - s11^2 ) (ie mismatched loss)
radiated power (Prad) = Pacc * radiated efficiency
and the gains are calculated as followed:
realised gain = 4piU / Pinc
gain = 4piU / Pacc
Directivity = 4piU / Prad
If you think carefully, realised gain is smaller than gain. But of course realised gain has included all the facts that an antenna has some mismatching loss and loss in efficiency. While gain and directivity excludes one of these losses respectively.
Hi,
incident power (Pinc) = 1W
accepted power (Pacc) = Pinc * (1 - s11^2 ) (ie mismatched loss)
radiated power (Prad) = Pacc * radiated efficiency
and the gains are calculated as followed:
realised gain = 4piU / Pinc
gain = 4piU / Pacc
Directivity = 4piU / Prad
If you think carefully, realised gain is smaller than gain. But of course realised gain has included all the facts that an antenna has some mismatching loss and loss in efficiency. While gain and directivity excludes one of these losses respectively.
The term ‘realized gain’ is sometimes used to differentiate the gain defines by IEEE.
According to to the IEEE standars, gain does not includes losses arising from :
*- impedance mismatches(reflection losses).
*- Polarization mismatches(losses).
The difference between gain and realized gain is
Gain = (4*Pi* radiation intensity)/Incident power
Realized Gain = (4*Pi* radiation intensity)/Accepted power
radiation intensity = radiated power per unit solid angle
As accepted power is always lesser than incident power so Realized gain is always greater than Gain.
Dear Hayder S. Ahmed ,
First u need to understand the following
incident power (Pinc) = 1W accepted power (Pacc) = Pinc * (1 - s11^2 ) (ie mismatched loss) radiated power (Prad) = Pacc * radiated efficiency
and the gains are calculated as followed:
realised gain = 4piU / Pinc gain = 4piU / Pacc Directivity = 4piU / Prad
If you think carefully, realised gain is smaller than gain. But of course realised gain has included all the facts that an antenna has some mismatching loss and loss in efficiency. While gain and directivity excludes one of these losses respectively.
for real time application always use Realized Gain.
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