Simulation of bow-tie THz antenna using hybrid finite element method and spectral ray tracing technique

In this paper, we propose a hybrid method that uses commercially available Finite Element Method (FEM) software and our in-house developed Spectral Ray Tracing (SRT) algorithm. The method is used for calculating the radiation patterns of complex lens antenna such as a bow-tie antenna backed by silicon lens. A traveling-wave terahertz photomixer integrated with a coplanar stripline (CPS) waveguide is used to generate the radiation that couples to the antenna. We employ HFSS, a FEM solver, to model THz propagation along the CPS line and planar bow-tie. Once the near-field distribution is found, the SRT method is then applied to find the radiation patterns and gain of the bow-tie antenna backed by a silicon hyper-hemispherical lens. The results are compared with full FEM simulation of the antenna-lens structure.