Dielectric Properties Measurement Based on Split Ring Resonator For Microfluidic Characterization

In this work, a bridge element approach based on the circular SRR configuration is proposed for accurate measurement in terms of complex permittivity and the loss tangent. It is observed that the proposed inter-connected bridge structure based on split ring resonator provides better sensitivity for dielectric measurement when compared with the standard microwave SRR sensors. The sensor operating at 1 to 6 GHz frequency range with 2.5μL sample volume at a time. The mathematical derivation is generated by loading sample with a standard reference of the materials in order to develop the empirical model for the determination of complex permittivity and the loss tangent. As demonstrated by the results, the unloaded Q-factor improves more than 400 over the narrow bandwidth at operating frequency of 2.3 GHz and provides less than 5 dB of the insertion loss. The measured data of each sample are in good agreement with the corresponding reference values available in the literature having a typical average detection error of less than 2.04%. By comparison, this design has an identical performance goal and provides excellent sensing capability which can be implemented in chemical and biosensor applications.