Good Stability Performance of SPP Transmission Lines to Substrate Perturbation

Abstract

The performance of modern microwave and radiofrequency (RF) electronic systems partially depends on the substrate. However, the relative permittivity $\varepsilon_r$ and the conductivity $\sigma$ of the substrate can be easily distorted owing to the change of temperature and humidity of the environment, especially in some extraordinarily special circumstances. Such kind of substrate perturbation can make circuits and systems unstable and affect their performance seriously. In this paper, we proposed a new method to break this challenge by utilizing the strong field confinement of artificial surface plasmon polariton (SPP) transmission line (TL). As a comparison, the performance distortions of both microstrip and SPP TL caused by substrate perturbation are analyzed theoretically and numerically, and a stronger stability of SPP TL under substrate perturbation is indicated. In another word, SPP TL possesses an outstanding ability to withstand violent change of environment.