Broadband coaxial cavity resonator for complex permittivity measurements of liquids

A novel cavity perturbation technique using coaxial cavity resonators for t he measurement of complex permittivity of liquids is presented. The method employs two types of resonators (Resonator I and Resonator II). Resonator I operates in the frequency range 600 MHz-7 GHz and resonator II operates in the frequency range 4 GHz-14 GHz. The introduction of the capillary tube f illed with the sample liquid into the coaxial resonator causes shifts in th e resonance frequency and loaded Q-factor of the resonator, The shifts in t he resonance frequency and loaded Q-factor are used to determine the real a nd imaginary parts of the complex permittivity of the sample liquid, respec tively, Using this technique, the dielectric parameters of water and nitrob enzene are measured. The results are compared with those obtained using oth er standard methods. The sources of errors are analyzed.