1. Alam, S., M. T. Islam, and H. Arshad, "Gain enhancement of a multiband resonator using defected ground surface on epoxy woven glass material," The Scientific World Journal, 2014.
2. Rajawat, A., P. K. Singhal, S. H. Gupta, and C. Jain, "Gain enhancement of microstrip patch antenna using H-shaped defected ground structure," Progress in Intelligent Computing Techniques: Theory, Practice, and Applications, 2018.
3. Zheng, Y., et al. "Metamaterial-based patch antenna with wideband RCS reduction and gain enhancement using improved loading method," IET Microwaves, Antennas & Propagation, Vol. 11, No. 9, 1183-1189, 2017.
doi:10.1049/iet-map.2016.0746
4. Saravanan, M., V. B. Geo, and S. M. Umarani, "Gain enhancement of patch antenna integrated with metamaterial inspired superstrate," Journal of Electrical Systems and Information Technology, 2-9, 2018.
5. Kim, J. H., C. H. Ahn, and J. K. Bang, "Antenna gain enhancement using a holey superstrate," IEEE Transactions on Antennas and Propagation, Vol. 64, No. 3, 1164-1167, 2016.
doi:10.1109/TAP.2016.2518650
6. Cao, W., B. Zhang, A. Liu, T. Yu, D. Guo, and Y. Wei, "Gain enhancement for broadband periodic endfire antenna by using split-ring resonator structures," IEEE Transactions on Antennas and Propagation, Vol. 60, No. 7, 3513-3516, 2012.
doi:10.1109/TAP.2012.2196959
7. Liu, Z., P. Wang, and Z. Zeng, "Enhancement of the gain for microstrip antennas using negative permeability metamaterial on low temperature co-fired ceramic (LTCC) substrate," IEEE Antennas and Wireless Propagation Letters, Vol. 12, 429-432, 2013.
doi:10.1109/LAWP.2013.2254697
8. Roy, S. and U. Chakraborty, "Gain enhancement of a dual-band WLAN microstrip antenna loaded with diagonal pattern metamaterials," IET Communications, Vol. 12, No. 12, 1448-1453, 2018.
doi:10.1049/iet-com.2018.0170
9. Khandelwal, M. K., B. K. Kanaujia, and S. Kumar, "Defected ground structure: fundamentals, analysis, and applications in modern wireless trends," International Journal of Antennas and Propagation, 1-22, 2017.
doi:10.1155/2017/2018527
10. Dgs, G. S., "Investigation of novel tapered hybrid defected ground structure (DGS)," International Journal RF and Microwave Computer-Aided Engineering, 544-550, 2005.
11. Paulraj, A. J., D. A. Gore, R. U. Nabar, and H. Bolcskei, "An overview of MIMO communications — A key to gigabit wireless," Proceedings of the IEEE, Vol. 92, No. 2, 198-217, 2004.
doi:10.1109/JPROC.2003.821915
12. Pandit, S., A. Mohan, and P. Ray, "A compact four-element MIMO antenna for WLAN applications," Microwave and Optical Technology Letters, Vol. 60, No. 2, 289-295, 2018.
doi:10.1002/mop.30961
13. Sharawi, M. S., et al. "A CSRR loaded MIMO antenna system for ISM band operation," IEEE Transactions on Antennas and Propagation, Vol. 61, No. 8, 4265-4274, 2013.
doi:10.1109/TAP.2013.2263214
14. Yang, L., S. Yan, and T. Li, "Compact printed four-element MIMO antenna system for LTE/ISM operations," Progress In Electromagnetics Research Letters, Vol. 54, 47-53, 2015.
15. Anitha, R., P. V. Vinesh, K. C. Prakash, P. Mohanan, K. Vasudevan, and S. Member, "A compact quad element slotted ground wideband antenna for MIMO applications," IEEE Transactions on Antennas and Propagation, Vol. 64, No. 10, 4550-4553, 2016.
doi:10.1109/TAP.2016.2593932
16. "Gaussian beam,", Online Available: https://en.wikipedia.org/wiki/Gaussian beam.
doi:10.1109/TAP.2016.2593932
17. Bhuiyan, M. D. S. and N. C. Karmakar, "Defected ground structures for microwave applications," Wiley Encyclopedia of Electrical and Electronics Engineering, 1-31, 2014.
18. Balanis, C. A., Antenna theory: Analysis and Design, 4th Edition, JohnWiley & Sons, Inc, Canada, 2016.
19. Blanch, S., J. Romeu, and I. Corbella, "Exact representation of antenna system diversity performance from input parameter description," Electronics Letters, Vol. 39, No. 9, 705, 2003.
doi:10.1049/el:20030495
20. Han, W., X. Zhou, J. Ouyang, Y. Li, R. Long, and F. Yang, "A six-port MIMO antenna system with high isolation for 5GHz WLAN access points," IEEE Antennas and Wireless Propagation Letters, Vol. 13, 880-883, 2014.
doi:10.1109/LAWP.2014.2310739
21. Malviya, L., R. K. Panigrahi, and M. V. Kartikeyan, "Circularly polarized 2 × 2 MIMO antenna for WLAN applications," Progress In Electromagnetics Research C, Vol. 66, 97-107, 2016.
doi:10.2528/PIERC16051905
22. 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.
doi:10.1109/TAP.2011.2109685
23. Malviya, L. D., R. K. Panigrahi, and M. V. Kartikeyan, "A 2 × 2 dual-band MIMO antenna with polarization diversity for wireless applications," Progress In Electromagnetics Research C, Vol. 61, 91-103, 2016.
doi:10.2528/PIERC15110401