High‐gain compact rectangular dielectric resonator antenna using metamaterial as superstrate

A compact high‐gain rectangular dielectric resonator antenna (RDRA) using metamaterial (MTM) as superstrate for C‐band applications is proposed in this article. The proposed antenna consists of coaxial‐fed RDRA with 50 unit cells of MTM arranged in 5 × 10 layout as superstrate. Each unit cell is constructed of two parallel eight‐shaped copper strips printed over both faces of a dielectric substrate to provide negative refractive index from 7.3 to 8.1 GHz covering the maximum bandwidth of RDRA. The extracted lumped equivalent circuit model of unit cell of MTM shows concurrence with electromagnetic simulations. The use of MTM superstrate increases the peak gain of the antenna by 89% through simulation and 86% experimentally. The measured results show that the proposed antenna achieves an impedance bandwidth of 16.1% over a band of 7.18‐8.44 GHz, with a peak gain of 14 dBi at 7.8 GHz.