title: Point matching: a new electronic method for homogenizing the phase characteristics of giant magnetoimpedance sensors.
abstract: Recently, our research group at PUC-Rio discovered that magnetic transducers based on the impedance phase characteristics of GMI sensors have the potential to multiply by one hundred the sensitivity values when compared to magnitude-based GMI transducers. Those GMI sensors can be employed in the measurement of ultra-weak magnetic fields, which intensities are even lower than the environmental magnetic noise. A traditional solution for cancelling the electromagnetic noise and interference makes use of gradiometric configurations, but the performance is strongly tied to the homogeneity of the sensing elements. This paper presents a new method that uses electronic circuits to modify the equivalent impedance of the GMI samples, aiming at homogenizing their phase characteristics and, consequently, improving the performance of gradiometric configurations based on GMI samples. It is also shown a performance comparison between this new method and another homogenization method previously developed.
authors.affiliation: Department of Electrical Engineering, Pontifícia Universidade Católica do Rio de Janeiro, PUC-Rio, Rio de Janeiro, 22451-900, Brazil.
authors.forename: E Costa
authors.initials: EC
authors.lastname: Silva
authors.affiliation: Postgraduate Program in Metrology, Pontifícia Universidade Católica do Rio de Janeiro, PUC-Rio, Rio de Janeiro, 22451-900, Brazil.
authors.forename: C R Hall
authors.initials: CR
authors.lastname: Barbosa
authors.affiliation: Department of Electrical Engineering, Pontifícia Universidade Católica do Rio de Janeiro, PUC-Rio, Rio de Janeiro, 22451-900, Brazil.
authors.forename: L A P
authors.initials: LA
authors.lastname: Gusmão
authors.affiliation: Postgraduate Program in Metrology, Pontifícia Universidade Católica do Rio de Janeiro, PUC-Rio, Rio de Janeiro, 22451-900, Brazil.
authors.forename: Y
authors.initials: Y
authors.lastname: Leipner
authors.affiliation: Postgraduate Program in Metrology, Pontifícia Universidade Católica do Rio de Janeiro, PUC-Rio, Rio de Janeiro, 22451-900, Brazil.
authors.forename: L G S
authors.initials: LG
authors.lastname: Fortaleza
authors.affiliation: Postgraduate Program in Metrology, Pontifícia Universidade Católica do Rio de Janeiro, PUC-Rio, Rio de Janeiro, 22451-900, Brazil.
authors.forename: E Costa
authors.initials: EC
authors.lastname: Monteiro