Slot Loaded Triple Band Microstrip Antenna for GSM Application

The Broader bandwidth in microstrip antenna can be recognized using electrical thicker substrate with thickness greater than
$0.07\lambda_{0}$
using proximity feeding. As getting proper impedance matching between basic and greater order modes of microstrip antenna is difficult at such a thick substrate, realization of multiband response with same substrate thickness is not possible. Hence for getting multiband response with 5% bandwidth at each band, in this paper a study is proposed on thinner substrate. First a broadband E-shaped suspended microstrip antenna designed on thicker substrate of
$0.09\lambda_{0}$
for 900MHz with 240MHz (32%) bandwidth is discussed. Then in depth analysis for realization of multiband response from the same configuration but fabricated on electrically thinner substrate with electrical thickness
$0.05\lambda_{0}$
is presented. The optimized configuration is fabricated and tested on suspended proximity fed low cost glass epoxy substrate that results into triple band response respectively at 840MHz, 1040MHz and 1650MHZ with bandwidth around 2% to 7% and gains more than 8dB with broadside radiation pattern. Due to operating frequency range and comparative high gain proposed antenna is suitable for GSM application.