A novel, miniature multiple input multiple output (MIMO) ultra wide band (UWB) antenna with dual notched characteristics is proposed. The antenna incorporates a tapered microstrip feed line with two radiating patch structures procured by the incorporation of two ellipses with a circle and a reduced ground structure. The proposed antenna is printed on an FR-4 substrate having a concise size of 40 x 22 mm2 to cover -10 dB bandwidth of 3.18-11.26 GHz with fractional bandwidth of 112%. The two notched bands 3.31-3.99 GHz for WiMAX and 4.97-5.93 GHz for WLAN accomplished by two T-shaped parasitic structures are etched above ground plane and inverted U- shaped slots etched on radiating patch, respectively. The isolation of < -15 dB is realized by inserting a T-shaped stub in between two patch elements. The measured MIMO diversity characteristics are the evidence of that the proposed antenna is appropriate for portable wireless applications.
2. Costa, J. R., E. B. Lima, C. R. Medeiros, and C. A. Fernandes, "Evaluation of a new wideband slot array for MIMO performance enhancement in indoor WLANs," IEEE Transactions on Antennas and Propagation, Vol. 59, No. 4, 1200-1206, 2011.
3. Karimian, R., H. Oraizi, S. Fakhte, and M. Farahani, "Novel F-shaped quad-band printed slot antenna for WLAN and WiMAX MIMO systems," IEEE Antennas and Wireless Propagation Letters, Vol. 12, 405-408, 2013.
4. Bait-Suwailam, M. M., O. F. Siddiqui, and O. M. Ramahi, "Mutual coupling reduction between microstrip patch antennas using slotted-complementary split-ring resonators," IEEE Antennas and Wireless Propagation Letters, Vol. 9, 876-878, 2010.
5. Zhang, S. and G. F. Pedersen, "Mutual coupling reduction for UWB MIMO antennas with a wideband neutralization line," IEEE Antennas and Wireless Propagation Letters, Vol. 15, 166-169, 2016.
6. Assimonis, S. D., T. V. Yioultsis, and C. S. Antonopoulos, "Design and optimization of uniplanar EBG structures for low profile antenna applications and mutual coupling reduction," IEEE Transactions on Antennas and Propagation, Vol. 60, No. 10, 4944-4949, 2012.
7. Farahani, H. S., M. Veysi, M. Kamyab, and A. Tadjalli, "Mutual coupling reduction in patch antenna arrays using a UC-EBG superstrate," IEEE Antennas and Wireless Propagation Letters, Vol. 9, 57-–59, 2010.
8. Assimonis, S. D., T. V. Yioultsis, and C. S. Antonopoulos, "Computational investigation and design of planar EBG structures for coupling reduction in antenna applications," IEEE Transactions on Magnetics, Vol. 48, No. 2, 771-774, 2012.
9. Varzakas, P., "Average channel capacity for rayleigh fading spread spectrum MIMO systems," International Journal of Communication Systems, Vol. 19, No. 10, 1081-1087, 2006.
10. Zhu, J., B. Feng, B. Peng, S. Li, and L. Deng, "Compact CPW UWB diversity slot antenna with dual band-notched characteristics," Microwave and Optical Technology Letters, Vol. 58, No. 4, 989-994, 2016.
11. Gorai, A., A. Dasgupta, and R. Ghatak, "A compact quasi-self-complementary dual band notched UWB MIMO antenna with enhanced isolation using Hilbert fractal slot," International Journal of Electronics and Communications, 2018, doi: https://doi.org/10.1016/j.aeue.2018.06.035.
12. Liu, X. L., Z. D. Wang, Y.-Z. Yin, and J. H. Wang, "Closely spaced dual band-notched UWB antenna for MIMO applications," Progress In Electromagnetics Research C, Vol. 46, 109-116, 2014.
13. Bhattacharya, A., B. Roy, S. K. Chowdhury, and A. K. Bhattacharjee, "An isolation enhanced, printed, low-profile UWB-MIMO antenna with unique dual band-notching features for WLAN and WiMAX," IETE Journal of Research, 2019, DOI: 10.1080/03772063.2019.1612284.
14. Li, J.-F., D.-L. Wu, and Y.-J. Wu, "Dual band-notched UWB MIMO antenna with uniform rejection performance," Progress In Electromagnetics Research M, Vol. 54, 103-111, 2017.
15. Manohar, M., R. S. Kshetrimayum, and A. K. Gogoi, "Printed monopole antenna with tapered feed line, feed region and patch for super wideband applications," IET Microwaves, Antennas and Propagation, 1-7, 2013.
16. Biswal, S. P. and S. Das, "A low profile dual port UWB-MIMO/diversity antenna with band rejection ability," International Journal of RF and Microwave Computer Aided Engineering, e21159, 2017, https://doi.org/10.1002/mmce.21159.
17. Abdalla, M. A. and A. A. Ibrahim, "Compact and closely spaced metamaterial MIMO antenna with high isolation for wireless applications," IEEE Antennas and Wireless Propagation Letters, Vol. 12, 1452-1455, 2013.