Measurement of liquid crystal's dielectric permittivity in the microwave range using inductive coupled ring resonator

摘要

For the measurement of dielectric permittivity of liquid crystal, we developed inductive coupled ring resonator. The dielectric permittivity of nematic liquid crystal(BL006) was determined in the 3 - 33 GHz frequency range by using a inductive coupled ring resonator. The frequency performance of ε'{sub}(//) (the long axis of the liquid crystal molecules is parallel to the direction of the r.f. electric field E{sub}(rf)) and ε'{sub}┴ (perpendicular to F{sub}(rf)) can be obtained from the measured resonant frequencies of an inductive coupled ring resonator with or without DC electric field E0. In addition, the nematic liquid crystal's permittivity by this method is compared with the one by cutback method.