Investigations on metamaterial superstrates for gain enhancement in rectangular microstrip patch antenna

Abstract

Communication between the transmitter and receiver is very important for the newlinecommunication system to complete. The inevitable component of a communication system is newlinethe antenna. Antennas that are larger in size became compact with the invention of planar newlineantennas. Shortcoming of planar antennas is its lower gain compared to conventional newlineantennas. Hence radio engineers are focusing on improving the gain of planar antennas. If newlinegain is increased, it improves the range and efficiency of the antenna. Also, these antennas newlinecan be employed in situations where the transmitted and received signal strength should be newlinehigh. The higher the gain of the antenna, the higher the signal to noise ratio of the transmitted newlineand received signals. Various gain enhancement techniques are reported in literature. One newlinesuch solution is to employ metamaterials. Metamaterials are artificial structures whose newlineparameters, like the permittivity, permeability, and refractive index, can be varied based on newlinethe requirements of different applications. In this thesis, metamaterial superstrates are newlineincorporated with the conventional rectangular microstrip patch antenna to increase the gain newlineof the antenna. The metamaterial superstrates are kept above the rectangular microstrip patch newlineantenna for its gain enhancement. This thesis mainly focuses on the 2.4 GHz frequency band, newlinewhich finds application in WiFi and WLAN. The gain of the antenna is enhanced by two newlineapproaches. The metamaterial superstrates act as a partial reflective surface forming a Fabry newlinePerot cavity that leads to the gain enhancement. Secondly, the superstrates possess near-zero newlinerefractive index that concentrates the electromagnetic waves and thereby increasing the gain newlineof the antenna. The thesis presents six different metamaterial superstrates for achieving gain enhancement in newlinerectangular microstrip patch antennas. newline