Although microstrip antenna are basically poor radiators, but now a day these poor radiators have gained importance and created interest in research during the last decade due to many advantage over conventional antennas. These advantages of mircostrip antenna have led to multi uses especially in high-speed space vehicles, satellites, missiles, tanks and other strategic applications in defense. The plasma medium present during the voyage of space shuttles interacts with antenna, which may modify the antenna characteristics. Thus in present chapter an attempt has been made to study the radiation properties of microstrip antenna in homogeneous plasma medium. For this the analysis of circular patch in homogeneous plasma has been carried out. The effect of collision frequency on the radiation is also considered extensively. The details of entire investigations are given in following sections of the paper.