Predicting Cole-Cole parameters of microfluids with microstrip technology

In this paper we present the novel design of a microstrip sensor to measure the broadband complex permittivity of small fluid samples and accurately predict their Cole-Cole parameters. This novel approach differs from prior works by placing the fluid analyte in an enclosed chamber underneath the trace of a suspended microstrip, allowing for better overlap between the electromagnetic fields and the fluid in comparison with microfluidic sensors in coplanar technology. A simple direct measurement technique that exploits device symmetry is proposed to extract the dielectric properties of the fluid from full 2-port scattering parameters and is validated through simulation data.