Quad-Band Circularly Polarized Tunable Graphene Based Dielectric Resonator Antenna for Terahertz Applications

A Cylindrical Dielectric Resonator antenna (CDRA) along with silicon based Rectangular Dielectric Resonator (RDR) slab is proposed in this paper for terahertz (THz) applications. This antenna provides multi-band response at different resonant frequencies. Unique feature of the proposed antenna is, it provides Circular Polarization (CP) behaviour at quad band in the field of THz dielectric resonator antennas and also CP tuning is achieved by varying graphene potential of the antenna. Furthermore this antenna shows both Right Hand CP (RHCP) and Left Hand CP (LHCP) behaviour at different resonant frequencies. A rectangular slab is incorporated with CDRA knows CPDRA to achieve CP response. Results show that a maximum gain of 6.67 dB, maximum radiation efficiency of 89%, 10 dB Impedance Bandwidth (IBW) of 4.66% (8.59-9THz), 2.98% (10.88–11.21THz), 4.83% (14.19–13.52THz) and 5.86% (15.88–16.84), Axial Ratio Bandwidth (ARBW) of 1.83% (8.66–8.82 THz), 2.16% (10.94–11.18), 3.84% (13.26–13.78 THz) and 4.8% (16.04–16.83 THz) is achieved by the combination of CDRA and Rectangular slab. For antenna tunability, the upper layer of CDRA is layered with graphene material and CP performance of antenna is analyzed for different values of graphene chemical potential. This new approach for the tuning and obtained results make the proposed Quad band CP DRA as unique and is suitable for THz applications.