Permittivity measurement of common solvents using the CSRR based sensor

In this paper, the microwave characterization of common polar and non-polar solvents has been carried out using the planar resonant sensor. The proposed sensor resonates at 2.65 GHz due to the etched complementary split ring resonator (CSRR) in the ground plane of the microstrip-line. The test solvent is filled into a container which covers the CSRR and is mechanically pressed against the ground plane with water proof adhesive filling the gap between them. The solvent inside the container changes the capacitance of the CSRR which causes a shift in the resonant frequency. This frequency shift is used for the measurement of the dielectric properties of solvent samples. The proposed sensor is numerically verified and experimentally tested to estimate the dielectric properties of various standard solvents with a typical error of 2-4%.