Tri-band high gain polarization reconfigurable split ring resonator based dielectric resonator antenna for terahertz applications

A polarization reconfigurable tri-band dielectric resonator antenna (DRA) is designed and numerically investigated for THz applications. The designed rectangular DRA made of silicon is excited by a silver nanostrip feed. The unique feature of the proposed DRA is the incorporation of dual split ring resonators (SRRs) connected with graphene layer. The SRRs are used to excite orthogonal modes required to achieve circular polarization response in the THz bands. The tunability in polarization is achieved by varying the chemical potential of the graphene layer used to connect the outer ring of the two SRRs. The proposed circularly polarized DRA (CPDRA) achieves a triple band with an impedance bandwidth of 4.96–5.52 THz, 6.85–7.12 THz, and 8.5–9.4 THz. The dual 3-dB axial ratio bandwidth of 5–5.6 THz and 8.8–9.4 THz with a peak gain of 7 dBi is obtained by the proposed design. The CPDRA exhibits stable left-hand circular polarization radiation pattern with RHCP below 15 dB in the boresight directions. This novel approach for tuning the polarization and triple band impedance bandwidth makes the proposed design a suitable candidate for THz communication, imaging, and sensing applications.