VOL 6, NO 4, APRIL 2011 ISSN 1819-6608 ARPN Journal of Engineering and Applied Sciences ©2006-2011 Asian Research Publishing Network (ARPN) All rights reserved www.arpnjournals.com IMPROVING BANDWIDTH RECTANGULAR PATCH ANTENNA USING DIFFERENT THICKNESS OF DIELECTRIC SUBSTRATE Ali A Dheyab Al-Sajee and Karim A Hamad Department of Electronic and Communication, College of Engineering, Al-Nahrain University, Iraq E-Mail: alidiab70@yahoo.com ABSTRACT Microstrip patch antenna has some drawbacks of low efficiency, narrow band (