BaSrTiO/sub 3/ interdigitated capacitors for distributed phase shifter applications

In this letter, BaSrTiO/sub 3/ (BST) interdigitated capacitors on sapphire substrates have been investigated. The tunability and quality factor of interdigital capacitors have been optimized for microwave and millimeter wave applications. A monolithic K-band phase shifter circuit that employs voltage tunable BaSrTiO/sub 3/ (BST) interdigitated capacitors is presented here.