antenna-theory.com

[peshalnayak]

If the return loss at a specific frequency is close to zero(say around -2 dB) and the radiation efficiency at that point is around 80 %, then does this mean that the antenna also radiates at this frequency? Does it mean that this frequency can be used as a frequency of operation?

I'm simulating a design in HFSS wherein the radiation efficiency is shown to be around 80% for non-radiating frequencies (determined from return loss) as well. Does this mean that my design will not work?

Please help me as early as possible as this is a part of my final year undergraduate project.

[admin]

First: you're saying radiation efficiency is 80%, and this (as you define it) definitely must not include mismatch loss. Your mismatch loss can be found from the VSWR calculator:
http://www.antenna-theory.com/definitions/vswr-calculator.php

At a VSWR=8, s11=-2dB, so that your mismatch loss is 4 dB. If you are at an antenna efficiency of -0.8 dB (approximately), then this can't include the effect of your mismatch loss.

If your antenna is 80% efficient, then yes that means your antenna radiates. That is pretty clear - if the best possible antenna is 100% efficient, how could you conclude otherwise?

Your question isn't well formed, it doesn't make a lot of sense