A Comparative Analysis of Hairpin Resonator and Split Cuboid Resonator

Abstract

In this study, comparative analysis is being presented for the basic hairpin resonator and improved hairpin resonator. The device is designed to possess a resonant frequency of about 3 GHz. Design has been optimized by changing dimensions of a basic hairpin resonator in a manner so as to increase its sensitivity. Simulation in HFSS software was done to study effects on resonant frequency, quality factor ‘Q factor’ and sensitivity with varying resonator dimensions. Three different polar liquids i.e distilled water, methanol and dimethyl sulfoxide, are used for sensitivity analysis. Introduction of these liquids into resonator gap results in perturbation of electric field. Shift in resonant parameters and their sensitivities is observed for these resonators with these liquids. The design in which maximum shift is obtained in these parameters was considered as optimized design. Optimized design resembled a cuboid with a split. This novel design is referred as split cuboid resonator (SCR). Simulation results of both resonators are compared for validation of concept. Later on, the proposed design was fabricated and then tested with Vector Network Analyzer (VNA) in order to verify the simulation results. The analysis and comparisons of hairpin resonator and SCR with respect to resonant frequency, Q factor and sensitivity were carried out for the two polar liquids i-e dimethyl sulfoxide and methanol. These liquids were filled in capillary tube and that tube was placed in the gap of hairpin resonator and then analyzed on VNA. This method was repeated for SCR as well. The comparisons and analysis depict that the experimentation results are in close agreement with the results obtained from simulations. Hence the extractions from simulation have been justified with the help of experimentation. The shift in the Q factor, resonant frequency and sensitivity of the SCR is greater than the hairpin resonator.