patch antenna basics

Who can share Basic deign concept of Annular Ring Patch antenna
For example. the relationship between rad/ centre freq

you can simply use the cavity model for annular rings... look in microstrip antenna design handbook, or any other microstrip antenna book...

hi
you can use the following perfect refrence papers.
1. "I/P impedance of annular ring microstrip antenna using circuit theory approach" IEEE Trans on antenna and propagation Vol. AP-33, No.4, PP.369-374, April 1985.
2. "A broad -Band annular ring Microstrip Antenna" LEEE Trans. on Antennas and Propagation Vol. AP-30, No.5, PP 918-922 sep. 1982.
3. Vector Hankel Transform of Annular ring MA" IEEE Trans. on Antennas and Propagation Vol. AP-30 No4, pp. 637-644 1982.
4. wider Band Microstrip Antenna for CP" IEEE Antenna and propagation Vol AP 36 No 2, pp 157-163 feb 1988
5. generalized Transmission line model of Microstrip patches" proc. inst. elec, eng. Vol 132, pt.H, pp 193-198 Apr 1985.


Regards
Hasan