Antennas designed by using conventional metallic waveguides have a poor performance due to the high losses of non-ideal conductors. To avoid this problem, low-loss Silicon-On-Insulator (SOI) substrate is proposed. The proposed compact design of a patch antenna integrated on a SOI exhibits the multiband characteristics. The designing and simulation is done by antenna simulation tool Ansoft HFSS. The proposed design of the multiband antenna offers an improvement in the antenna characteristics. The calculated directivity, radiation efficiency and 10-dB impedance bandwidth of the designed antenna are 6.725dB, 90.8% and 18.6% respectively.