Two directional THz wave duplexer and filter based on graphene disks and rings

Abstract

Coating both sides of a dielectric spacer with graphene patterns, leads to a tunable meta surface which acts as a THz duplexer. Two separate channels, reflection and transmission are considered as outputs ports while the aim is to minimize absorption ration. The presented structure consists of periodic arrays of graphene patterns on both sides of silicon dioxide as substrate. Moreover, the patterns include disks and rings are biased differently compared to conventional patterns which makes it possible to achieve tunable behaviors versus external bias. utilizing equivalent circuit models (ECM) for graphene patterns and dielectric, the whole structure is modeled by passive RLC branches.According to the simulation outputs, the presented structure can transmit and reflect incident THz waves at desired frequencies in 0.1 THz to 30 THz which makes it an ideal candidate for manipulating THz waves in terms of transmission and reflection. The THz duplexer can transmit and reflect incident waves at 1-3.3 THz as wide-band and 1.05 THz as narrow-band operation. Such a tunable device is in great demand for indoor communications, security, less harmful medical imaging and space related researches.

A High Performance Duplexer Based on Dual-mode E-type Resonator

“…The most commonly used duplexer is to combine two bandpass filters into a three-port impedance matching network [8][9][10]. A large-sized T-shaped joint circuit is widely adopted in the combination to produce good transmission in one passband and good attenuation in the other.…”