LAUSR

A novel compact spoof surface plasmonic (SSP) transmission line (TL) consisting of a stem-shaped periodic structure is proposed to achieve high field confinement in the higher frequency range (microwave to terahertz). The dispersion characteristic of the proposed stem-shaped SSP unit cell exhibits much lower asymptotic frequency and higher field confinement than the conventional coplanar waveguide (CPW) and the rectangular SSP unit cell structure without increasing the overall transverse dimension, i.e., improved signal propagation performance with reduced cross-sectional area. The numerical study of the multi-conductor line based on the proposed stem-shaped SSP unit cell shows that it has improved propagation and isolation features in comparison to the conventional TL structures. Here, the improved isolation is characterized in terms of the mutual coupling (MC) between the two adjacent lines designed using the stem-shaped SSP unit cell, which is not found to significantly increase with an increase in the coupling length unlikely in the conventional TLs. For the proposed SSP-based multi-conductor line, the MCs for 1.6, 2.25, and 4.15λ coupling lengths with fixed separation of 0.175λ are found to be 22, -19.8, and -17.55dB, respectively.