In communication systems, there are various types of micro strip antenna that can be used for many applications. This paper mainly focuses on the simple design of inset rectangular micro strip patch antenna to operate at frequency of 2.45GHz for rectenna design. The study involves using HFSS simulator to design the antenna dimensions and to determine its performance. This antenna is based on a thickness of 1.6mm Flame Retardant 4 (FR-4) substrate with a dielectric constant of approximately 4.7, inset feed and has a ground plane. After simulation, the antenna performance characteristics such as return loss, VSWR, gain, radiation pattern are obtained.