The resonant frequency of a microstrip patch (rectangular, square, and circular) changes as soon as an identical patch is brought closer than 0.2λ. Closed form expressions are presented for the E-plane coupled configuration from which this altered resonant frequency may be easily computed. These expressions may be readily used in the computer aided design of microstrip antenna arrays.
2. Hammerstad, E., "Computer aided design of microstrip couplers with accurate discontinuity models,", ELAB Report N7034, 54-57, Trondheim-NTH, Norway.
3. Krowne, C. M., "Dielectric and width effect on H-plane and E-plane couplings between rectangular microstrip antennas," IEEE Trans. Ant. Propagat., Vol. 31, No. 1, 39-47, Jan. 1983.
4. Sharma, A. K. and B. Bhat, "Spectral domain analysis of interacting microstrip resonant structures," IEEE Trans. Microwave Theory Tech., Vol. 31, No. 8, 681-685, Aug. 1983.
5. Zaker, R., C. Ghobadi, and J. Nourinia, "A modified microstrip-FED two-step tapered monopole antenna for UWB and WLAN applications," Progress In Electromagnetics Research, Vol. 77, 137-148, 2007.
6. Ang, B.-K. and B.-K. Chung, "A wideband E-shaped microstrip patch antenna for 5–6 GHz wireless communications," Progress In Electromagnetics Research, Vol. 75, 397-407, 2007.
7. Guney, K. and N. Sarikaya, "Resonant frequency calculation for circular microstrip antennas with a dielectric cover using adaptive network-based fuzzy inference system optimized by various algorithms," Progress In Electromagnetics Research, Vol. 72, 279-306, 2007.
8. Sadat, S., M. Fardis, F. G. Kharakhili, and G. Dadashzadeh, "A compact microstrip square-ring slot antenna for UWB applications," Progress In Electromagnetics Research, Vol. 67, 173-179, 2007.
9. Cui, B., C. Wang, and X.-W. Sun, "Microstrip array double-antenna (MADA) technology applied in millimeter wave compact radar front-end," Progress In Electromagnetics Research, Vol. 66, 125-136, 2006.
10. Schneider, M. V., B. Glance, and W. F Bodtmann, "Microwave and millimeter wave hybrid integrated circuits for radio systems," Bell Syst. Tech. J., 1703-1725, 1969.