Analysis of Nonlinearity in Step in Width Discontinuity of Superconducting Coplanar Waveguide Structures

Abolfazl Mostaani | Seyed Mohammad Hassan Javadzadeh

---

URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=43797
Date :  2017/09/01
Publish in :    IEEE Transactions on Applied Superconductivity
DOI :  https://doi.org/10.1109/tasc.2017.2691582
Link :  http://ieeexplore.ieee.org/document/7893792/
Keywords :Nonlinearity, Discontinuity, Superconducting, Co-Planar, Waveguide

Abstract :

---

In this paper, the nonlinearity in superconducting coplanar waveguides (SCPWs) with step in width discontinuities has been analyzed using a distributed nonlinear circuit model. In such structures, nonlinearities depend on the current distribution of the central strip of the SCPW. A numerical electromagnetics approach based on the method of moments, which analyzes high-frequency planar circuits, determines the current distribution. This is used to obtain the nonlinear circuit elements of a discontinued SCPW structure. The equivalent nonlinear circuit model can be solved using the harmonic balance method as has been done in an example of a step in width SCPW. The accuracy of the model is shown by comparison of results from an experiment for a SCPW transmission-line structure. Moreover, all different types of step discontinuities in a SCPW have been compared and the efficient structure, which has the minimum nonlinearity has been defined.