Experimental Complex Permittivity Characterization of Mixed Dielectric Materials over a Broadband Frequency

Abstract

The complex permittivity of mixed organic materials that are widely employed for micro-strip transmission lines is experimentally investigated. Micro-strip transmission line test patterns consisting of two different dielectric materials are fabricated on an organic substrate. In order to extract the complex permittivity over a broadband frequency, we determine the per-unit-length (PUL) capacitance and conductance with the S-parameters measured from 10 MHz to 40 GHz by using a vector network analyzer (VNA). In order to show the physical validity of the determined complex permittivity of mixed organic materials, we calculate the wave propagation factor and compare it with nominal and measured values. The complex permittivity characterized in this paper is shown to reflect accurately the loss of a transmission line at the high frequency.