This paper presents a study of the effects of line width on the resonance frequency and bandwidth of a microstrip square-ring antenna at its primary resonance frequency. Although such ring antennas operating in TM11 mode are smaller than regular patch antennas, they are not explored much as they are considered to have poor bandwidth and efficiency at this mode. We have used a transmission line model to study their input characteristics and found that a non-uniform width ring antenna has significantly better (nearly double) bandwidth and radiation efficiency than a uniform width square ring antenna. Extensive simulations were done and a prototype non-uniform width square ring antenna is fabricated and tested to verify these results.
2. Garg, R. and V. S. Reddy, "Edge feeding of microstrip ring antennas," IEEE Trans. on Antennas and Propagation, Vol. 51, No. 8, 1941-1946, Aug. 2003.
3. Mayhew-Ridgers, G., J. W. Odendaal, and J. Joubert, "Single-layer capacitive feed for wideband probe-fed microstrip antenna elements," IEEE Trans. on Antennas and Propagation, Vol. 51, No. 6, 1405-1407, Jun. 2003.
4. Ramirez, R. R., F. De Flaviis, and N. G. Alexopoulos, "Single-feed circularly polarized microstrip ring antenna and arrays," IEEE Trans. on Antennas and Propagation, Vol. 48, No. 7, 1040-1047, Jul. 2000.
5. Kokotoff, D. M., J. T Aberle, and R. B. Waterhouse, "Rigorous analysis of probe-fed printed annular ring antennas," IEEE Trans. on Antennas and Propagation, Vol. 47, No. 2, 384-388, Feb. 1999.
6. Latif, S. I. and L. Shafai, "Investigation on probe-fed open ring microstrip antenna for miniaturization," Microwave and Optical Technology Letters (MOTL), Vol. 48, No. 11, 2175-2179, Nov. 2006.
7. Chen, W.-S., C.-K. Wu, and K. L. Wong, "Square-ring microstrip antenna with a cross strip for compact circular polarization operation," IEEE Trans. on Antennas and Propagation, Vol. 47, No. 10, 1566-1568, Oct. 1999.
8. Sultan, M. A., "The mode features of an ideal-gap open-ring microstrip antenna," IEEE Trans. on Antennas and Propagation, Vol. 37, No. 2, 137-142, Feb. 1989.
9. Wu, Y. S. and F. J. Rosenbaum, "Mode chart for microstrip ring resonator (short Paper)," EEE Trans. on Microwave Theory and Techniques, 487-489, Jul. 1973.
10. Liu, J.-C., B.-H. Zeng, L. Badjie, S. Drammeh, S.-S. Bar, T.-F. Hung, and D.-C. Chang, "Single-feed circularly polarized aperture-coupled stack antenna with dual-mode square loop radiator," IEEE Antennas and Wireless Propagation Letters, Vol. 9, 887-890, 2010.
11. Rezaiesarlak, R., F. Hodjat Kashani, and E. Mehrshahi, "Analysis of capacitively coupled microstrip-ring resonator based on spectral domain method," Progress In Electromagnetics Research Letters, Vol. 3, 25-33, 2008.
12. Mink, J. W., "Circular ring microstrip antenna elements," IEEE Antennas and Propagation Society Int. Symp. Digest, 605-608, 1980.
13. Bafrooei, P. M. and L. Shafai, "Characteristics of single- and double-layer microstrip square-ring antennas," IEEE Trans. on Antennas and Propagation, Vol. 47, No. 10, 1633-1639, Oct. 1999.
14. Garg, R., P. Bhartia, I. J. Bhal, and A. Ittipiboon, Microstrip Antenna Design Handbook, Artech House, Boston, 2001.
15. Mayhew-Ridgers, G., J. W. Odendaal, and J. Joubert, "New feeding mechanism for annular-ring microstrip antenna," Electronics Letters, Vol. 36, No. 7, 605-606, Mar. 30, 2000.
16. Row, J. S., "Design of square-ring microstrip antenna for circular polarization," Electronics Letters, Vol. 40, No. 2, Jan. 22, 2004.
17. Ansari, J. A., R. B. Ram, and P. Singh, "Analysis of a gap-coupled stacked annular-ring microstrip antenna," Progress In Electromagnetics Research B, Vol. 4, 147-158, 2008.
18. Ren, Y. J. and K. Chang, "An annular ring antenna for UBW communications," IEEE Antennas and Wireless Propagation Letters, Vol. 5, No. 1, 274-276, 2006.
19. Mellah, S., M. Drissi, J. M. Floch, and J. Citerne, "Theoritical and Experimental investigation of smooth and discrete microstrip ring antennas," IEEE Antennas and Propagation Society Intern. Symp., Vol. 4, 2196-2199, 1992.
20. Latif, S. I. and L. Shafai, "Dual-layer square-ring (DLSRA) for circular polarization," IEEE Antennas and Propagation Society Intern. Symp., Vol. 2A, 525-528, 2005.
21. Chen, S. H., J. S. Row, and C. Y. D. Sim, "Single-feed square-ring patch antenna with dual-frequency operation," Microwave and Optical Technology Letters, Vol. 49, 991-994, 2007.
22. James, J. R. and P. S. Hall, Handbook of Microstrip Antennas, Vol. 1, Peter Peregrinus Ltd., London, 1989.
23. Chew, W. C., "A broad-band annular-ring microstrip antennas," IEEE Trans. on Antennas and Propagation,, Vol. 30, No. 5, 918-922, Sep. 1982.
24. Pal, A., S. Behera, and K. J. Vinoy, "Design of multi-frequency microstrip antennas using multiple rings," IET Microwaves Antennas & Propagation, Vol. 3, 77-84, 2009.
25. James, J. R., et al., "Some recent developments in microstrip antenna design," IEEE Trans. on Antennas and Propagation, Vol. 29, 124-128, Jan. 1981.
26. Pozar, D. M. and B. Kaufman, "Increasing the bandwidth of a microstrip antenna by proximity coupling," IEE Electronics Letters, Vol. 3, No. 8, 368-369, Apr. 1987.
27. Pozar, D. M., Microwave Engineering, John Wiley & Sons. Inc., 2005.
28. Cheng, D., "Compact multi-band multi-port antenna,", US Patent 7289064, Oct. 30, 2007.
29. Behera, S. and K. J. Vinoy, "Microstrip square ring antenna for dual-band operation," Progress In Electromagnetics Research, Vol. 93, 41-56, 2009.