Analytical Model of Guided Waves in Periodically Perforated Dielectric Structure and Its Applications to Terahertz Substrate-Integrated Image Guide (SIIG)

This article presents and derives an analytical model for accurately analyzing lossy dielectric waveguides in the THz regime. By considering the dielectric loss of waveguides and applying the impedance boundary condition (IBC), the proposed method can accurately simulate the waveguiding behavior. By applying the Fourier series expansion along with the Floquet theory, an analytical model is developed, which can effectively account for periodic perforations, which describes an inherent feature of substrate-integrated dielectric waveguides at THz frequencies. The applicability and high accuracy of the proposed method are demonstrated by providing several examples and comparisons with measurements from a fabricated prototype. The efficiency of the proposed method in terms of simulation runtime is compared with some commercial EM software packages. These results demonstrate that while the proposed method maintains a minimum accuracy of 95% compared with the CST Studio Suite and Ansys HFSS software, the simulation runtime is reduced by 300 times.