A four-port self-multiplexing tunable graphene based dielectric resonator antenna with defective ground structure for high isolation and MIMO capabilities

Abstract

Objectives and design

A novel self-multiplexing terahertz antenna with four tunable ports is proposed in this work. The configuration comprises four rectangular dielectric resonators (DRs) affixed to a substrate, which are excited through L-shaped microstrip-fed slots positioned beneath them. To guarantee efficient isolation among the tunable antenna components, periodic unit cells are introduced into the ground plane, forming a defective ground structure (DGS). Each L-shaped slot element is equipped with a graphene strip to regulate the tunability of each DR element.

Results and applications

This antenna can operate in various modes with resonant frequencies at 4.01, 4.23, 4.37, and 4.57 THz. It holds potential for future terahertz wireless applications that require the utilization of adjacent channels with distinct communication frequencies. Furthermore, a four-port antenna design is implemented, offering tunable MIMO capabilities with self-quadruplexing ability. The MIMO parameters, specifically the envelope correlation coefficient (ECC) and diversity gain (DG), have been assessed and found to fall within acceptable limits across the operating frequency bands. Additionally, an equivalent circuit model (ECM) is analysed to shed light on the antenna's working principle and verify the obtained results.