Efficient Analysis of Longitudinally Corrugated Rods Using Asymptotic Boundary Conditions for Investigation of Conductor Losses and Plasmonic Field Localization

This paper proposes an analytical modal method that provides quick yet accurate surface-wave solutions for tackling longitudinally corrugated conducting circular rods with dielectric-filled grooves. Using asymptotic corrugations boundary condition—the asymptotic corrugated boundary condition, this elegant albeit nonfull-wave approach offers a simple way to obtain not only the dispersion relation between the frequency and wavenumber but also the modal field distribution from the solution of the final system matrix for the amplitude coefficients. The proposed method is validated with an independent full-wave simulation software. Parametric studies for the field localization are carried, and the results of conductor losses as well as radial attenuation are also reported. The results of measurements conducted on a manufactured corrugated rod are presented at the end.