Temperature Controlled Artificial Coaxial Line for Microwave Characterization of Liquid Crystal

As a tunable dielectric, liquid crystals (LCs) promise as a suitable passive tunable material for microwave components. Hence, precise knowledge of dielectric properties are necessary to design these microwave components. In this paper, a broadband temperature controlled artificial coaxial line measurement setup is presented to characterize LCs in a broad microwave frequencies. Material features, which are functions of dielectric properties, of different LCs are extracted at the room temperature from 3.5 GHz to 30 GHz. Especially being important for the applications which need stable functionalities in a wide temperature range, temperature dependent properties of several LCs, including commercially available LCs named GT3-23001 and K15, are provided from 10 deg C to 60 deg C at 20 GHz.