Design of high gain, broadband resonant cavity antenna with meta-material inspired superstrate

Abstract

A broadband high gain planar meta-material based Resonant Cavity Antenna (RCA) operating at C-band is proposed. The RCA is modeled using simple ray tracing method. The unit cell metamaterial consists of Artificial Magnetic Conductor (AMC) and square patch laminated on either side of a lossy commercial dielectric material of dielectric constant 4.4 & thickness 1.6 mm, is used as the superstrate to design RCA. Square patch is the capacitive type and that AMC as inductive. Effects of the reflection phase of the substrate decide the high gain of the antenna. A cylindrical dielectric resonator antenna (CDRA) is embedded into the cavity as a feed. The proposed antenna achieves 22.4 dBi gain with 2 layers of 4 × 4 array superstrate with a bandwidth of around 5.1 GHz. The full-wave analysis is performed to extract the impedance matching, radiation pattern & gain of the composite RCA. A prototype antenna is fabricated and tested for verification of experimental results which was found to be well correlated. It also shows that the proposed RCA achieves −10 dB impedance bandwidth of 72.72% ranging from 4 to 9.1 GHz with a high gain around 22.4 dBi.