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).

thanks

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.

Thanks

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.