Electrical Circuit Modeling of Sensor Magneto-Impedances With a Square-Root Frequency Dependence

In this paper, a novel lumped electrical model for magneto-impedance sensors based on square-root of the frequency f (√f) is introduced. The model is mathematically derived using an alternative approximation of √f that leads to an approximate transfer function with a finite number of products of poles and zeros. This approach can be easily implemented in circuit simulators, such as SPICE (Simulation Program with Integrated Circuit Emphasis) by means of current conveyors circuits and linear passive elements, such as resistors, capacitors, and inductors. These elements are interconnected using impedance converters based on Senani's model to implement the poles and zeros of the transfer function. The scope and validity of the model were demonstrated through circuit simulations using spice, and compared with experimental results. The model can be used in the electronic signal conditioning stage for optimizing and/or for researching new cheap low-power practical electronics circuits.