Microstrip patch antennas are becoming increasingly useful because they can be printed directly onto a circuit board. Microstrip antennas are becoming very widespread within the mobile phone market. Patch antennas are low cost, have a low profile and are easily fabricated.The aim of this book is to clarify the design and Analysis process of a rectangular Microstrip Patch Antenna and study the effect of antenna dimensions Length (L), Width (W) and substrate parameters relative Dielectric constant, substrate thickness (t) on the Radiation parameters of Bandwidth and Beam-width.