Wide-band measurement of the complex permittivity of dielectric materials using a wide-band cavity

Abstract

A technique is presented for the characterization of dielectric materials over a wide band of frequencies (RF to millimeter wave region). The cavity structure offers a well-defined reference plane for precision measurements of dielectric characteristics. The dielectric sample completely fills a cylindrical cavity adapted to a precision air line(s). Two configurations are considered: the terminating cavity configuration, in which the cavity is adapted to the end of a precision air line; and the through-cavity configuration where the cavity is placed between two precision air lines. The measured scattering parameters, the reflection and/or the transmission coefficients, are used to determine the complex permittivity of the dielectric sample.< >