A Calibration Technique for Measuring the Complex Permittivity of Materials with Planar Transmission Lines

摘要

A simple two-standard calibration procedure for determining the permittivity of a material from the propagation constant measured with planar transmission lines is presented. The suitability of this procedure is demonstrated by using a coplanar waveguide transmission-line sensor to measure the permittivity of five liquids, covering a wide range of complex permittivity. The results agree closely with expected values when the radiation and conductor losses are small. This technique allows the permittivity of materials to be measured without knowing the planar transmission-line dimensions apart from the line lengths.