[ask] Antenna parameters

Hi,

I'm sorry if my question "tickle" you...
it's because I really don't understand it well, I'd read some reference but still don't find good explanation on it (looks like the problem is on me）

OK, here are my questions:
1. Some mention 'bout the parameter of antenna as S11, S22, S12, S21. What those variables mean actually? So far I only understand that S11 is related to the matching or VSWR (please correct me if I'm wrong).
2. What TEM is actually mean? (not the abbreviation offcourse). And sometimes I found 'bout TM10, TM11, etc what that's mean?

Please spare your time helping me to understand those...
I'm looking forward for your answer...
thanks before...

hello micro_tech:

Have you download David M.Pozar'
Microwave Engineering,a useful technology book?
I think you can find the answer youself.

best reguard!

Hi antboy,

Thanks for your replay...
Yes I've heard about that book, but unfortunately I can't find it...
Do you have the ebook version of that book?

All you need to do is a search is this forum,
you will find it. It has been uploaded many times.

Hi,

S11- Gives Return loss at port 1(Transmitting and receiving at port 1).
S22- Gives Return loss at port 2(Transmitting and receiving at port 2).
S12- Transmitting at Port 2 and Receiving at Port 1.
S21- Transmitting at Port 1 and Receiving at Port 2.

S12=S21 in case of reciprocal network.