Murad, Ridwan (PhD)Leyla, Ahmed2021-08-262023-11-282021-08-262023-11-282021-04http://etd.aau.edu.et/handle/12345678/27751The performance of microstrip antenna arrays is greatly undermined by the excitation of space waves and surface waves which cause mutual coupling between microstrip antenna elements. Mutual coupling between antenna elements can affect the side lobe levels, beam position and frequency bandwidth of arrays. Mutual coupling through space waves are very strong if the array elements are very close to each other, and they can be suppressed by increasing the interelement spacing between the array elements. Defected ground structure (DGS) is a type of metamaterials designed at ground that is used to minimize the surface wave and prevents the degrading in performance of an antenna. Frequency Selective Surface (FSS) is also useful in miniaturization of a designed antenna. In this thesis work, a ground plane is loaded with defected ground structure and frequency selective surface techniques to minimize the effect of coupling loss and to enhance the performance of the MSPA. A rectangular-aperture coupled microstrip patch antenna is first designed for S-band application and 2x1 MSPA antenna array is formed by using the optimized design of the individual antenna for an inter element spacing l/4 (where l is the operating wave length of the antenna which is equal to 130.43mm). Then a simulation is carried out to measure the S11, S12, and other parameters of the antenna. Finally, DGS &FSS are applied on the antenna and the reduction in coupling loss is analyzed using HFSS Software. The result of the study indicates, 2X1 rectangular micro strip patch antenna array inserting FSS at the ground plane were proposed for 2.3GHz which has an improved bandwidth of 71.8MHzand mutual coupling effect is -35.668dB when compared with an antenna array with DGS.en-USMicro-Strip Antenna (MSA)Defected Ground Structure (DGS)Frequency Selective Surface (FSS)Thesis