A complete circuit model for terahertz spoof surface plasmon polariton waveguides for ultrafast and accurate synthesis of terahertz integrated circuits

Official URL: https://dx.doi.org/10.1109/ACCESS.2025.3582843

The increasing demand for ultra-wideband wireless communications has pushed requirements of integrated circuits (ICs) to terahertz band. Operation in the terahertz band requires ultra-high efficiency for all the building blocks in ICs; however, the conventional passive components prevent achieving desired output power levels. Moreover, these components also strongly impede the synthesis of ICs as the design flow requires an enormous number of full-wave analyses. In this paper, we present the first-ever, complete, closed form, theoretical model for Terahertz Spoof Surface Plasmon Polariton Waveguides (THz-SSPP WGs), which hold the record for the lowest loss performance among all the planar waveguides at 0.3 THz. The electromagnetic field distribution around the THz-SSPP WG is non-uniform that even makes the solution of the problem of a nonlinear differential equation of multiple variables even more challenging. Because the guided-wavenumber is non-linear because of the dispersive behavior of the waveguide and the field distribution, hence the boundary conditions depend on all the corrugation dimensions, substrate thickness, and material properties. The proposed model is the first complete closed-form model not only among all THz-SSPP WGs, but also any single conductor planar waveguide. The proposed model illustrates the behavior of the confined and propagated electromagnetic wave around the THz-SSPP WGs, where the field distribution pattern changes as any of the waveguide parameter changes in contrast with any conventional waveguide with a ground.