Microwave complex permittivity of voltage-tunable nematic liquid crystals measured in high resistivity silicon transducers

Abstract

A split post dielectric resonator is used to determine the effect of AC bias voltage on the microwave complex permittivity of nematic liquid crystals. High resistivity silicon transducers separated by 100 μm are bridged by nematic liquid crystals and their properties determined. The in-plane permittivity of liquid crystals can be effectively tuned (change of effective permittivity of up to 8) by increasing the AC bias voltage from 0 to 6 V. Using high resistivity silicon allowed us to obtain tunable dielectric stacks with relatively small dielectric losses at microwave frequencies. © 2013 American Institute of Physics.