A New Microstrip Pickup Coil for Thin-Film Permeance Meters

In this paper we propose an application of microstrip line for a single-turn pickup coil in the thin-film permeance meters. This coil has two electric ports with one terminated into 50 Ω. It is free from LC resonance up to a few GHz because the microstrip line does not resonates and because the stray capacitance between the pickup coil and the driving sheets is small as compared with the conventional figure-8 coil. We measured the thin film permeance up to 700 MHz which is the upper frequency limit of the driving sheets used. The proposed coil has a potential to measure thin-film permeances over the wide range from 1 MHz up to a few GHz.