Microstrip patch antennas are the handiest antennas for the present trend of applications in communications. The well-known beneficial mechanical characteristics (low profile, light weight, planar but conformal to non-planar structures, easy to fabricate), flexibility in terms of electromagnetic parameters like radiation pattern, gain, impedance, polarization and low cost are the key features for the success of such antennas. High efficiency antennas are essential to cater the requirements of various military oriented space vehicles like spacecraft, aircraft, satellite and missile applications where dimensions of installation are important as size, weight, performance, ease of installation and easy integration to the circuit. Microstrip antenna array are most apt for such applications, but the limitation of such antennas are gain and the bandwidth. The order of gain is low for patch antenna which is generally in the choice of 1-2dB.To increase gain and bandwidth factors the utilization of material with low dielectric constant having greater thickness is employed. However, this generates surface waves. So, proper thickness of substrate is selected. In this paper, microstrip patch having pentagon shape uses probe feed technique for various substrate materials such as Roger’s RT/Duroid 5880 (tm), Roger’s RO4003 (tm) and FR4 epoxy. The results of the three substrate designs are acquired for the resonant frequencies 6.5 GHz, 6.6 GHz, and 6.7 GHz respectively. The whole analysis is carried out using Ansoft HFSS software version 17.0. The characteristics like bandwidth, amplification factor (gain), return loss and radiation patterns of the different antenna are assessed, related and the same are presented at the end.