antenna-theory.com

[peshalnayak]

I read some papers and they are defining various types of bandwidths:
1. with 6 dB return loss definition (-6dB line cutting the return loss plot determines the bandwidth)
2. with 8 dB return loss definition
3. with 10 dB return loss definition.

If I use the first definition, then my bandwidth fulfills the requirements for WLAN 2.4 GHz applications. If I use the other two, it does not strictly cover the entire band of 2.400-2.484 GHz- only partially covers it.
So, can this antenna be used for WLAN applications or not?

Which definition should I use and why?
Why should the other definition not be used?
Please help me out with this confusion.

[admin]

Return loss isn't necessarily a great metric for determining bandwidth. It's pretty arbitrary - which is why someone could choose an upper limit of 6 dB and someone else 10 dB.

Really you care about efficiency, and for WLAN applications it matters what type of range for a given data rate you are trying to achieve.

If you want something that works about as well as a typical phone, you can get away with a crappier antenna.

-6dB is equivalent to a VSWR of 3, which is generally about as high as you want to go for mismatch loss. Some people will expect better, but it really depends on the application.

Anyway, its tough to answer your question because in some applications -6dB is ok and in some you need -10 dB return loss.