<p>Antennas are long used for communication of data since a century and their usage has been diversified over the past two decades and the antennas also entered the domain of medical fields. A rectangular microstrip patch antenna has been designed on a substrate integrated waveguide with frequency selective surface which is in the shape of a square. The design of this antenna with SIW are done by using CST on a low cost FR4 substrate where є<sub>r</sub> =4.4, h=1.58 mm and tan δ=0.0035. The SIW structure merit is utilized on the traditional FSS is simulated and verified by using CST.</p>