Spoof Surface Plasmon Polariton Based Ultra-Wideband Filters in Terahertz Region: A Finite Element Method Study

Conventional electrical waveguides have become a major obstacle in future high frequency ultra fast data transmission. These traditional electrical micro-stripe lines suffer from low transmission, high insertion loss, and total reflection of the excitation signal at terahertz range. The Spoof Surface Plasmon Polariton (SSPP) based waveguide can be a better alternative with low loss and tight field confinement within the metal-dielectric interfaces. This article investigates the transmission characteristics of a single SSPP waveguide filter with uniform corrugation on both sides of the metal line. Additionally, the effect of geometric parameters of SSPP filter on transmission coefficients (S
21
) and reflection coefficients (S
11
) has been investigated. The proposed SSPP model is simulated with six different design parameter values. Among them, the best performance is obtained with groove width 3 µm, height 20 µm and groove period of 20 µm. For this optimized design, an ultra-wide passband of approximately 400 GHz is found with a low signal reflection of below -8dB (approximately).