Is this Valid ? please check it

I have made rectangular patch antanna for fr=2Ghz and er=2.2 and h=3..then i got the frequency band like attach figure...

Please see it and tell me is it right frequency band i.e. PLOT ?

Which band can we get from fig ....

When we check return loss, basically it's a log form for S11, for the antenna to be accepted, the band must be lower than -10dB. This is because it's related to the S11 parameter. I saw your image, your band is too small 1.55GHz to 2.1GHz.

What kind of antenna you designing? Triband? UWB?

first of all thank you for giving me ans.
I am designing a Microstrip patch antenna for 1.7 to 2.3 GHz Band..for my Final year project.......

this is my designing dimensions...

Please give me some suggestion to get 1.7 to 2.3 Ghz band...
thanks

basically you want to shift the band from your current result to the right side.

It's easy.

Try these changes (do it one by one - not all together, and then simulate and check if these parameters u tweak will shift the band region)

1. Change the thickness of microstrip width (increase it or reduce it)
2. Adjust the microstrip location (shift it left or right)
3. Adjust your patch width or height

Change all these parameters one by one, and check the results again. See which parameter that change can shift the band region.

Your antenna is very simple.