Non-destructive Measurement of Complex Permittivity of Board Type Dielectric Sample using Rectangular Cavity Resonator

Abstract

In this paper, the author presents the non-destructive measurement method that the imaginary part of the complex permittivity of thin dielectric sample which conforms the slit of the cavity resonator is estimated. First, the author calculates the quality factor using finite difference time domain (FDTD) method, on condition that a thin sample is inserted into the rectangular cavity resonator. The agreement is obtained between calculation and measurement, under the variation of the complex permittivity. Second, the author provided here the measurement chart by the relation between the quality factor calculated by FDTD method and the imaginary part of the permittivity, and then the measurement chart could be used for practical measurement. The comparison of the complex permittivity of the material determined by the present method with FDTD and perturbation method at 2GHz is performed. It was confirmed that the present method is effective for estimation the complex permittivity.