Demonstration of in-situ dielectric permittivity measurement using precision probing technique

Abstract

This paper proposes a breakthrough in-situ dielectric permittivity measurement technique for a circuit substrate with various planar circuits on the substrate. The proposed technique uses a quasi-resonator at the backside of an RF probe, which is contacted at the middle of the feed line of the planar circuits. Dielectric permittivity is calculated using the difference between the resonance frequencies of two measurements with different probe-contact positions. The proposed technique can be used for the feed lines of a matched-transmission line and an attenuator. Therefore, it can be used for the evaluation of circuit substrates with various devices. The proposed technique can realize the in-situ dielectric measurement of circuit substrates, and it is expected to be a powerful tool for the investigation of the defects in practical RF devices because it does not require any resonator for a device under test.