DefinePK

Abstract

A three-layer microstrip resonator is introduced to measure complex permittivities of mediumloss liquids. The device is configured such that the first layer containing the liquid under test; a sheet ofpolytetrafluoroethylene (PTFE) is embedded in the middle layer, and the third layer functions as the baseon which the patch is printed. The base layer is inverted on PTFE layer, and reflection coefficient ismeasured from 2.5 GHz to 5 GHz. The complex permittivities are extracted from the resonant frequencyand the 10-dB bandwidth of S-parameter for different combinations of ethanol and methanol. Indeed,a three-layer microstrip resonator allows us to possess an affordable, and yet, high-accuracy electricaldevice to measure complex permittivities of medium loss liquids. FDTD method is used for analysingthe structure and the results obtained by using FDTD method and the experimental data indicate a highdegree of similarity.