[1] Ahmed Khidre, Kai-Fong Lee, Atef Z. Elsherbeni, and Fan Yang, “Wide Band Dual Beam U-Slot Microstrip Antenna”, IEEE Transaction on Antenna and propagation , vol. 61, no. 3, pp. 1415-1418, March 2013.

[2] S Bhunia “Effects of Slot Loading on Microstrip Patch Antennas”, International Journal of Wired and Wireless Communications Vol.1, Issue 1, October, 2012

[3] Amber Haidery, Reshma Tawde, Tazeen Shaikh,”l- Slot Rectangular Microstrip Patch Antenna for WiMAX and WLAN Application” International Journal of Emerging Technology and Advanced Engineering, Volume 3, Issue 10, October 2013.

[4] Kumari Nidhi Lal , Ashutosh Kumar Singh “Modified Design of Microstrip Patch Antenna for WiMAX Communication System”

[5] D.M. Pozar, Microwave Engineering. New York: Addison- Wesley, 1990, P.185.

[6] C. A. Balanis, Antenna theory: Analysis and Design. New York: Wiley, 1997, p. 734.

[7] Kai-Fong Lee, Fellow IEEE, and Kin-Fai Tong, Member IEEE “Microstrip Patch Antennas Basic Characteristics and Some Recent Advances”

[8] Kaushik Mandal and Partha Prtim Sarkar” High Gain Wide-Band U-Shaped Patch Antennas With Modified Ground Planes”, IEEE Transactions on Antenna and Propagation ,vol. 61, no.4,pp.2279-2282,April 2013.

[9] Teruhisa Nakamura and Takeshi Fukusako, “Broadband Design of Circularly Polarized Microstrip Patch Antenna Using Artificial Ground Structure With Rectangular Unit Cells” IEEE Transactions on Antenna and Propagation, VOl. 59, no.6,pp.2103-2110, June 2011