An Improved Method of Finding Complex Permittivity of Lossy Liquids

Abstract

An improved transmission/reflection method for high DK, DF liquid material is proposed. The conventional T/R method often requires a nearly-matched transmission line feeding, which is difficult to realize in high DK liquids. To overcome this problem, in this paper we propose a reference impedance transform technique based on the concept of pseudo-wave. The transformed S parameters will then exhibit better transmission due to better (virtual) matching. In addition, a time-gating method is proposed to solve the resulting equations and obtain smoother complex permittivity w.r.t. frequency. Experiments are conducted to verify the proposed method.