Design and analysis of microstrip patch antennas for multiband and wideband wireless communications

Abstract

In our work, several wide-slots made up by merging two or more different shapes are etched in the ground plane to obtain the wideband response. It is also seen that by merging two or more different Euclidean shapes (or hybrid) and using it as a radiating structure also shows the wideband response. Time domain analysis is also studied for the proposed wideband antenna structures for calculating their group delay and phase response. For this, two configurations, i.e., side-by-side (SS) and face-to-face (FF) are considered where two similar prototypes of the same antenna structures are placed at a certain distance. The transfer function (S21) is also considered while designing the wideband antenna structures. The multiple-input-multiple-output versions of both multiband and wideband antennas are also studied and proposed in this Thesis in order to support high data rates, enhanc ing channel capacity and combat multipath fading problems in wireless applications with no additional bandwidth utilization. The performance of the proposed MIMO antennas is investigated on the basis of their diversity performance parameters such as envelope correlation coefficient, diversity gain, total active reflection coefficient and channel ca pacity loss. The performance of these MIMO antennas when placed inside the portable devices gets affected by the presence of large ground plane (or PCB of their motherboard or large metallic body of vehicle when mounted on their roof-top). Hence, the effect of having large ground plane, USB connector and housing with extended ground plane on both S11 and S21 parameters are also studied