Materials for freedom fabrication of GHz tunable dielectric photonic crystals

Photonic crystals are of interest for GHz transmission applications, including rapid switching, GHz filters, and phased-array technology. 3D fabrication by Robocasting enables moldless printing of high solid loading slurries into structures such as the "woodpile" structures used to fabricate dielectric photonic band gap crystals. In this work, tunable dielectric materials were developed and printed into woodpile structures via solid freefrom fabrication (SFF) toward demonstration of tunable photonic crystals. Barium strontium titanate ceramics possess interesting electrical properties including high permittivity, low loss, and high tunability. This paper discusses the processing route and dielectric characterization of (Ba_xSr_1-XTiO₃):MgO ceramic composites, toward fabrication of tunable dielectric photonic band gap crystals.