Size reduction and bandwidth enhancement in metamaterial antenna / Umi Namirah Zakaria

This thesis presents a design of metamaterial patch antenna incoperates with Electromagnetic Band Gap (EBG) structure for WiMax application. The patch antenna was fabricated on RO3003 substrate together with three circular EBG structure on ground plane. The RO3003 substrate has relative permittivity, er = 3.0, and height, h = 0.75 mm. The patch antenna was designed to resonate at 3.5GHz. This metamaterial antenna is focusing on reducing the size and increasing the bandwidth. All simulations and measurements were done using Computer Simulation Technology Microwave Studio (CST-MWS) and Vector Network Analyzer (VNA) respectively. The metamaterial characteristics were tested for the negative permittivity and permeability using Nicolson-Rose-Weir (NRW). The simulation results show that the metamaterial antenna has improved the return loss, Su by 37.29% compared to the conventional antenna. The size of the metamaterial patch was reduced by 18.03% compared to the conventional antenna. The bandwidth was increased by 138.13% from the conventional antenna. In the measurement, the resonant frequency of the antenna is slightly shifted from the actual frequency. The both antennas shifted to the 3.545 MHz frequency which represented the return loss (Su) for the patch antenna with EBG and without EBG are - 26.694dB and -17.874dB respectively.