On the implementation of electromagnetic bandgap structures for enhanced performance on types of patch antennas

Abstract

In recent years there has been a growing interest in utilizing newlineElectromagnetic BandGap EBG structures in antenna and microwave newlineengineering This thesis presents the performance improvement of the patch newlineantenna incorporated with the Electromagnetic BandGap structures The newlineimpedance bandwidth is investigated for several different patch antennas with newlinevarious ground sizes Three of them are selected viz the single frequency newlinesquare patch antenna single frequency circular patch antenna and dual newlinefrequency slotted rectangular patch antenna Each of them represents a newlinedifferent shape and is fine tuned to exhibit its own resonant frequency and is newlineplaced above the ground plane Compactness and patch area reduction can be newlineachieved through suitable unitcells of EBG structures Then the three newlinedifferent unitcells of EBGs such as mushroom like spiral like and ring like newlinestructures are designed and operated at frequencies of 24GHZ 15GHz and newline18GHZ and 23GHz All the EBGs are surrounded by the aforementioned newlinepatch antennas the impedance bandwidth of all the three can not only be newlinematched but also the impedance bandwidth enhancement of 674 932 newlineand 11 75 7817 respectively is obtained Compared to the conventional newlinemushroom like EBG antenna the gain and bandwidth of 11 11 spiral like newlineEBG antenna is enhanced by 2 8dBi and 79 8 respectively newline newline