Method for nonlinear fitting and impedance analysis with LCR meter

In this paper new method for nonlinear fitting application is defined, described and tested. The method used the data acquired with LCR meter, nonlinear models of equivalent circuits, nonlinear fitting algorithm and iterative procedure for minimization mean square error between input data and nonlinear impedance model. The low cost LCR meter has been used and adopted to perform frequency range sweep impedance analysis and substitute more expensive impedance analyzer instruments. The method is tested in laboratory with different RLC circuit structures. Presented method for nonlinear fitting and impedance analysis can be applied on data acquired with different instruments according to application needs.

I. Introduction

Impedance analysis is very important in many fields, such as: energy harvesting [1], filter design [2], biomedical applications [3], etc.