Abdo, Mohammed (PhD)Hailu, Zewdu2018-06-292023-11-282018-06-292023-11-282008-01http://etd.aau.edu.et/handle/12345678/5033Conventional microstrip antennas in general have the attractive features such as low profile, light weight, easy fabrication, and conformability to mounting hosts. However, microstrip antennas inherently have a narrow bandwidth, low gain, and bandwidth enhancement is usually demanded for practical applications. In addition, applications in present-day mobile communication systems usually require smaller antenna size in order to meet the miniaturization requirements of mobile units. Thus, size reduction and bandwidth enhancement are becoming major design considerations for practical applications of microstrip antennas. For this reason, conducting studies to achieve compact and broadband operations of microstrip antennas is thought to be very important. The purpose of this thesis is to make a comparative study on the techniques that help to overcome the bandwidth constraint of microstrip patch antennas and to propose the better technique by taking different consideration such as the antenna gain, bandwidth and related issues. In this thesis work broad banding techniques like using feeding techniques (proximity coupled), stacked patches, parasitic arrangement of patches and the use of different shapes (i.e. E-shaped) are studied. The bandwidth obtained for each type of the antenna are 10.8%, 11.5%, 15.6% and 25.6% respectively with respect to the operating frequency of each of the antennas. The result shows that the E-shaped patch antenna has better performance. Key Words: patch antenna, return loss, bandwidth, gainenpatch antennaReturn lossBandwidthGainThesis