Nonlinear Dielectric Thin Films For Active and Electrically Tunable Microwave Devices

Abstract

AbstractWe have prepared electrically tunable and active microwave devices incorporating (superconducting YBa2Cu3O7-x)/(nonlinear dielectric SrTiO3) or (normal metal Au)/(nonlinear dielectric Sr0.5Ba0.5TiO3) bilayers. The dielectric layer thickness for these samples varied between 0.5 μm and 2 μm. The top electrode layer for each sample was patterned into a coplanar waveguide device structure. We have configured these devices as voltage-tunable resonators, voltage-tunable phase shifters, voltage-tunable mixers, and voltage-tunable filters. Under dc voltage bias, these prototype devices have exhibited up to 30% resonant frequency modulation, about 1°/mm-GHz phase shift, more than 40 dB change in mixed microwave power, and finetunable symmetric filter profile with less than 2% bandwidth and more than 15% adaptive range.