A compact printed and planar Multiple-Input Multiple-Output (MIMO) for Ultra Wideband (UWB) communications is presented. Two circular disc monopole antenna elements constitute the proposed UWB-MIMO antenna operating over the frequency band of 3.2-10.6 GHz. The isolation between the antenna ports has been enhanced to the value of more than 15 dB throughout the frequency band of interest. This enhancement is achieved by taking the advantage of an inverted-Y shaped stub that is being inserted on the ground plane of UWB-MIMO antenna. The insertion of the stub has also facilitated reduction of the size of the antenna, i.e., overall dimensions of the antenna are 40×68mm2. The proposed antenna is investigated both numerically and experimentally.
2. Federal Communication Commission (FCC), "Revision of part 15 of the commissions rules regarding ultra-wideband transmission systems," ET Docket 98-153, FCC 02-48, First Report and Order, Apr. 2002.
3. Dossche, S., S. Blanch, and J. Romeu, "Optimum antenna matching to minimize signal correlation on a two port antenna diversity system," Electronic Letters, Vol. 40, No. 19, 1164-1165, Sep. 2004.
4. Mak, A. C. K., C. R. Rowell, and R. D. Murch, "Isolation enhancement between two closely packed antennas," IEEE Transactions on Antennas and Propagation, Vol. 56, No. 11, 3411-3419, Nov. 2008.
5. Chebihi, A., C. Luxey, A. Diallo, P. Le Thuc, and R. Staraj, "A novel isolation technique for closely spaced pifas for umts mobile phones," IEEE Antennas and Wireless Propagation Letters, Vol. 7, 665-668, Nov. 2008.
6. Chiu, C.-Y., C.-H. Cheng, R. D. Murch, and C. R. Rowell, "Reduction of mutual coupling between closely-packed antenna elements," IEEE Transactions on Antennas and Propagation, Vol. 55, No. 6, 1732-1738, Jun. 2007.
7. Najam, A. I., Y. Duroc, J. F. A. Leao, and S. Tedjini, "A novel collocated antennas system for UWB-MIMO applications," Proc. IEEE International Radio and Wireless Symposium, 368-371, Jan. 2009.
8. Wong, K.-L., S.-W. Su, and Y.-L. Kuo, "A printed ultra-wideband diversity monopole antenna," Microwave Optical Technology Letters, Vol. 38, No. 4, 257-259, 2003.
9. Liu, L., H. Zhao, T. S. P. See, and Z.-N. Chen, "A printed ultra-wideband diversity antenna," Proc. IEEE International Conference on Ultra-Wideband, 351-356, Sep. 2006.
10. Kim, I., C. W. Jung, Y. Kim, and Y. Kim, "Low-profile wideband MIMO antenna with suppressing mutual coupling between two antennas," Microwave Optical Technology Letters, Vol. 50, No. 5, 1336-1339, May 2008.
11. Hong, S., K. Chung, J. Lee, S. Jung, S. S. Lee, and J. Choi, "Design of a diversity antenna with stubs for UWB applications," Microwave Optical Technology Letters, Vol. 50, No. 5, 1352-1356, May 2008.
12. Cheng, Y., W. J. Lu, C. H. Cheng, W. Cao, and Y. Li, Printed diversity antenna with cross shape stub for ultra-wideband applications, Proc. IEEE International Conference Communications Systems, 813-816, Nov. 2008.
13. Najam, A. I., Y. Duroc, and S. Tedjini, "Design and analysis of MIMO antennas for UWB communications," Proc. European Conference on Antennas and Propagation, Apr. 2010.
14. Choi, S. H., J. K. Park, S. K. Kim, and J. Y. Park, "A new ultrawideband antenna for UWB applications," Microwave and Optical Technology Letters, Vol. 40, No. 5, 399-401, May 2004.
15. Sheng, H., P. Orlik, A. M. Haimovich, L. J. Cimini, and J. Zhang, On the spectral and power requirements for ultra-wideband transmission, Proc. IEEE International Conference on Communications, Vol. 1, 738-742, May 2003.
16. Salonen, I. and P. Vainikainen, "Estimation of signal correlation in antenna arrays," Proc. International Symposium on Antennas, Vol. 2, 383-386, Nov. 2002.
17. Manteghi, M. and Y. Rahmat-Samii, "Multiport characteristics of a wide-band cavity backed annular patch antenna for multipolarization operations," IEEE Transactions on Antennas and Propagation, Vol. 53, No. 1, 466-474, Jan. 2005.