Broadband Analysis of Sample Permittivity on a Conductor-Backed Coplanar Waveguide

Understanding the interaction of electric fields with biosystems and developing biomedical diagnostic and therapeutic methods require knowledge of the dielectric properties of biomolecular systems. However, the large sample volumes needed for complex permittivity analysis hinder progress in this area. To address this issue, this paper presents a novel method for obtaining a broadband complex permittivity using a conductor-backed coplanar waveguide, which enables the measurement of dielectric properties of very small sample volumes (in the order of μL) and an explicit formula for complex permittivity. The method is validated using S-parameters of an aqueous solution of L-alanine at different concentrations and compared with an independent reference method.