Design of Microstrip resonator

Hi im Anil.
Im doing project on Microstrip resonator in HFSS.......So please guide me for resonator design,it's other applictions and
if possible suggest study material for it..........:)

Hello! I am a pretty newbie in this area, but maybe this will help you:

Look at microstrip resonator as a simple band-pass filter.

All you need is to
1) design good band-pass filter, with small losses (so you get enough amplitude for negative resistance to work)
2) put this filter in right position to get 180 phase shift, before RF signal bounces back to active device (so you overall phase shift is 360 degree)

Almost the same as with DRO. Can extrapolate theory about DRO to microstrip resonators (Q factors, etc.)

What is your case? parallel feedback or series feedback?

In parallel feedback you can put simple half-wavelength microstrip between gate and drain of FET. Looks exactly like parallel-feedback DRO, but there is simple microstrip instead of DRO puck.

In series feedback you can put hairpin banpass filter near gate microstrip. I saw paper where is spiral resonator placed near gate. Look the same as DRO series feedback on gate.

There are tons of papers on microstrip resonators. The most useful is papers about "ACTIVE INTEGRATED ANTENNA". Google for active integrated antennas (AIA), and you will get many useful information on that area. Briefly: AIA antennas is used as microstrip radiating resonator.

p.s. Also it's possible glue some special material above microstrip resonator to reduce losses.