Nonlinear Measurements of Electrochromic WO3/LiNbO3/NiO at Microwave Frequencies

In this paper and for the first time, nonlinear behaviour of an electronically tuneable electrochromic (EC) thin film material is investigated experimentally at microwave frequencies. The measurement setup based on the single tone method uses identical topologies for test cells based on SiO2 or Silicone Dioxide (SD) and EC dielectric materials for a mutual comparison study of the nonlinear behaviour of the tuneable EC dielectric. The measured third-order intercept point of EC test cells is around 80 dBm, which is larger than typical values for other tuneable technologies such as ferroelectrics and liquid crystals (LCs).

I. Introduction

Tuneable dielectric materials have potential applications in various integrated reconfigurable microwave devices, such as antennas, phase shifters and filters, to name but a few [1]. The use of this innovative control strategy requires precise characterization of the dielectric properties, and in this regard, numerous studies have been conducted to study dielectric properties of potential candidates such as ferroelectrics, [2], and liquid crystals (LC), [3].