High Frequency Permeance Measurements Using a Shielded Loop Coil

Abstract

We have developed a 1 MHz-2 GHz thin-film permeance meter using a shielded loop-coil type pickup coil. To measure the permeance accurately up to the GHz region, it is necessary to consider impedance matching throughout the driving plates and pickup coil, mode matching of the pickup coil, electromagnetic mode in the driving plates, and the voltage induced by an electric field. Errors can be reduced in the 500 MHz to 2 GHz range by taking account of the change in the input impedance of the pickup coil with and without a magnetic sample.