High - frequency MI in ferromagnetic microwires for magnetic sensor

The design of an advance strip cells on PCB board for VNA calibration which allows to measure the MI dependence at frequency up to GHz region has been discussed in this work. Different types of Co-based amorphous glass-coated microwires were investigated showing large MI changes even at GHz frequencies before and after ac-current annealing. It is found that the microwire at low frequency (less than 300 MHz) had the different behaviour in MI than the high frequency (above 300 MHz) which can be useful for the application of tensile stress to control the magnetic anisotropy even at GHz frequencies. Also, the effect of stress on MI at high frequencies in ac-current treatment of amorphous wire has the potential for developing stress sensitive applications especially for wireless operation at microwave frequencies.