A metamaterial inspired UWB circular antenna as superstrate for gain and directivity improvement’s

Abstract

A Near Zero refractive Index (NZIM) metamaterial inspired UWB circular antenna as a superstrate for gain and directivity improvement’s is presented and investigated in this work. The frequency range with S11 less than-10dB is from 4.5GHz to 12.5GHz. The permeability and permittivity of the (NZIM) has an extraordinary property that could be optimized to synchronously approach zero and have an effective wave impedance matching with air and near-zero index simultaneously, this feature of metamaterial gives the NZIM the ability to collimates the incident bending waves and gather it’s towards the normal direction. Hence the antenna performances in term of the gain and directivity will be enhanced. The studied metamaterial design is optimized and analyzed using CST microwave. Obviously, the antenna gain and directivity are enhanced by 4.8 and 4.89 respectively. The simulation of this developed metamaterial antenna has been optimized and performed by using Computer Simulation Technology-Microwave Studio (CST) and Ansof High Frequency Structure Simulator (HFSS).