The paper proposes design of an array antenna with proximity coupled feeding at frequency 2.55 GHz. At first, a linearly polarised rectangular patch antenna is discussed. The basic rectangular structure is modified using proximity coupled feed to enhance the impedance bandwidth. Then, in order to introduce circular polarisation, the patch structure is further modified into Split Ring structure. An Array of these Split Rings is constructed to increase the directivity. Inter-element spacing of the array is further changed with 5mm offset and it is observed that the antenna turns in to a dual band antenna. The performance of Split Ring Array Antenna (SRAA) is investigated in terms of relevant parameters viz. impedance bandwidth, gain, axial ratio and efficiency. The SR Array antenna exhibits qualitatively better performance and can be used for wireless LAN and WAN in MIMO environment.

1. Rajeev Mathur, Sunil Joshi, “A Novel Multiple Element Patch Antenna for Wireless MIMO Beamforming & WiMAX Applications” proceedings of “IEEE Sponsored - International Conference on Emerging Trends in Networks and Computer Communications (ETNCC-2011), Udaipur”, INDIA on 22-23 April 2011 and published in IEEE Explorer Digital Library
2. White Paper: A Practical Guide to WiMAX Antennas:MIMO and Beamforming Technical Overview, Motorola, Inc. www.motorola.com/wimax
3. Antenna Theory by C.A. Balanis.
4. G J Joshi, Shyam S Pattnaik, Swapna Devi, M R Lohkare, IETE ournal of research, Vol56, Issue 6, pp 373-379, Nov-Dec2010
5. The IEEE website.
6. Online. Available: http://www.ieee.org
7. R.W. Ziolkowski, “Applications of Metamaterial to realize efficient electrically small Antenna”, 0-7803-8842-9/05 IEEE International Workshop on Antenna Technology.
8. Pendry, J. B., A. J. Holden, D. J. Robbins, and W. J. Stewart, “Magnetism from conductors and enhanced nonlinear phenomena,” IEEE Trans. Microwave Theory.
9. Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specification, IEEE Std. 802.11, 1997.
10. G. Foschini and M. Gans, ““On Limits of Wireless Communications in a Fading Environment when Using Multiple Antennas”,” Wireless, Personal Communications, vol. 6, pp. 311–335, March 1998.
11. P. Wolniansky, G. Foschini, G. Golden, and R. Valenzuela, ““V-BLAST: An Architecture for Realizing Very High Data Rates Over the Rich-Scattering Wireless Channel”,” in Proc. 1998 URSI Int. Symp. on Sign.,Syst., and Elect., 1998, pp. 295–300.
12. M. Bengtsson and B. Ottersten, “Optimal and suboptimal transmit beamforming,” in Handbook of Antennas in Wireless Communications. CRC Press, Aug. 2001.
13. D. Gore, R. Heath, and A. Paulraj, “Statistical antenna selection for spatial multiplexing systems,” in Proc. 2002 IEEE Int. Conf. Communications, vol. 1, New York, NY, pp. 450–454.
14. L. C. Godara, “Applications of Antenna Arrays to Mobile Communications, Part I:Performance Improvement, Feasibility, and System Considerations” Proceedings of the IEEE, VOL. 85, NO. 7, JULY 1997 page 1032.

Array Antenna Split Ring Array Antenna Array MIMO Wireless Local area Networks Wide Area Network