Investigation of Enhanced Gain Miniaturized Patch Antenna Using Near Zero Index Metamaterial Structure Characteristics

This paper presents a novel miniaturized patch antenna with enhanced gain characteristics using a Near Zero Index Metamaterial Structure (NZIMS). The proposed antenna consists of a ground plane, rectangular radiating patch and inverted metamaterial structure, which provides wideband behavior, high gain and relatively good matching around 534 MHz. Moreover, the effects of high permittivity and permeability on Hilbert fractals reduced the size of the antenna. The antenna has a small area (44 mm x 58 mm) and offers an impedance bandwidth of 2.11% in 534 MHz. The gain of proposed antenna is better than similar previous works. An NZIMS material with Electric-LC Resonators (ELCR) is used to attain better gain performance and acceptable near-zero permittivity in superstrate. The simulation and optimization process was accelerated using equivalent material parameters for simulation of materials in substrate and superstrate. The simulation and measurement results of the antenna showed a gain of 7.27 dB and a miniaturization factor of 4.8. Both simulated and experimental results obtained for this antenna, validate better radiation performance at 534 MHz frequency range.