For wireless communication systems, the antenna is one of the most critical components. A good design of the antenna can relax system requirements and improve overall system performance. This book gives the design of a rectangular microstrip edge-fed and patch antenna array with a centre frequency of 13 GHz for Satellite applications whose frequency range is from 12 to 18GHz. A single element and 2×2 microstrip rectangular patch antennas was designed and simulated by using HFSS tool. The proposed patch antennas are used for RADAR and Satellite applications. The proposed antenna will be simulated for suitable frequencies in different applications for improving some antenna parameters like gain, return losses, radiation pattern, VSWR, etc.