antenna-theory.com

[The Alternative]

Antenna gain is usually given with relationship to a known antenna (such as a dipole or a isotropic). To give one example: a dipole has a gain of 2.5dbi.

However, I notice that many antenna modeling programs give a gain figure. This figure seems to be far too high. Just what is that these programs provide? How do they calculate the gain figure?

[admin]

Hmmm...what program are you using?

A good check to see if your using the program right (and to make sure the program runs correctly), is to perform the analysis on a simple half-wave dipole. The directivity and gain should both be roughly 2.15 dB or less, and if its much higher than something isn't correct.

[gelunmak]

I've the same experience of having incorrect gain value when using some simulations software.

Of course, i tried to use a simple dipole to test the software but the value is higher than the expected value of 2.15dBi.

So i don't rely too much on the gain value, instead i'll look at other parameter like beamwith, F/B ratio, shape of pattern, S11, S21 , ... etc.

Simulation software for me is design aid which help to confirm some new idea or to predict the performance before actually build the antenna.

I trust and rely more on experiment.