FABRICATION AND PERFORMANCE OF COPLANAR FERROELECTRIC PHASE-SHIFTER

Coplanar ferroelectric phase shifters have been fabricated from thin f ilms of barium strontium titanate (BST) and gold coplanar waveguide. T he ability for these devices to provide a variable phase shift is base d upon the change in dielectric constant of the BST with an applied de bias. We have fabricated coplanar phase shifters by three different s eries of fabrication steps. For each of the three devices, MgO was use d as the substrate, and the BST films were deposited by laser ablation . We describe the coplanar design, material deposition, and the high f requency testing. The phase shifters were tested at frequencies up to 35 GHz.