A new giant magneto-impedance head using magnetic microstrip lines

The performance of a novel magneto-impedance (MI) sensor head is described. The sensor is based on a magnetic microstrip line whose transmission impedance changes due to the permeability variation induced in the magnetic strip by external fields. The effects of device geometry on the performance is examined. It is found that output signal increases with both higher carrier power and narrower strip width. A microsensor with magnetic strip dimensions of 5/spl times/20 /spl mu/m demonstrated a high sensitivity of 6 mv/sub pp//Oe and a broad bandwidth of 300 MHz at an input power of 1 mW.