A variable fractional-order inductor design

Abstract

Recently, interest in fractional-order inductors (FOIs) has increased since theyallow for accurate and robust models of dynamical systems to be designed.However, practical implementation of these models has not been possible dueto the lack of single FOI realizations. To address this challenge, in this work,we propose a simple-to-realize fractional-order inductor design with variableconstant phase angle (CPA). The design relies on characteristics of transverseelectromagnetic (TEM) mode propagating on a coaxial structure filled withconductive material, more specifically NaCl-water solution and flour-basedmixtures. The CPA of the resulting FOI can be tuned by changing the conduc-tivity of the dough mixture. Analysis of the proposed FOI design show that theCPA can vary in a range from 0 to 90 . Two of these CPA values are verifiedagainst experiments in the frequency band changing from 1 to 10 MHz