A compact antenna structure for circular polarized terahertz radiation

A compact circular polarized graphene-based patch antenna is proposed for THz applications. The proposed antenna consists of a microstrip patch radiator made of graphene and is designed on silicon-di-oxide substrate. Initially, a linear polarized antenna is developed with an axial ratio of 40 dB. Further, the proposed antenna is modified to achieve circular polarization by blending the opposite edges of the radiating patch, which makes the antenna simple in design and easy for fabrication. It operates at 2.05 THz and an axial ratio bandwidth of 0.5 THz is achieved. The proposed circular-polarized antenna provides a maximum return loss of -22 dB and a VSWR less than 1.5 over the operating band. A significant gain of 5.02 dB and an efficiency of 95 % are observed. The design is simulated using 3D Full-wave EM simulator based on Finite Difference Time Domain (FDTD) method.