Modeling Nonlinearity in Superconducting Interdigital Capacitors and Its Effects on Metamaterial Structures

Behnam Mazdouri | S. Mohammad Hassan Javadzadeh

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=64281
Date :  2017/12/16
Publish in :    IEEE Transactions on Applied Superconductivity
DOI :  https://doi.org/10.1109/tasc.2017.2759246
Link :  http://ieeexplore.ieee.org/document/8059867/
Keywords :Modeling, Nonlinearity, Superconducting, Metamaterial

Abstract :

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Superconducting devices are known to indicate nonlinear behaviors such as harmonic generation and intermodulation distortion (IMD) even at low input powers. In this paper, nonlinear equivalent circuit model for superconducting interdigital capacitor (SIDC) is proposed. A numerical approach based on three-dimensional finite element method (3D-FEM) is used to compute the current distribution in SIDCs. Then closed-form expressions for kinetic inductance, resistance and geometrical nonlinear factor (GNF) of SIDCs are proposed. The proposed model can be analyzed nonlinearly by using of Harmonic Balance (HB) method to predict nonlinear phenomena. To validate accuracy of proposed nonlinear model, nonlinearity in a superconducting metamaterial structure consist of two SIDCs are predicted. Good agreement between calculated results and measured ones was found. Thereafter, based on the proposed model, other nonlinear behaviors of the considered structures are predicted and based on our new method, effects of nonlinearity on main parameters of the superconducting metamaterial structure such as phase constant, attenuation factor, plasma frequency, permittivity and permeability are analyzed.