Tunable electromagnetic bandgap structures based on ferroelectric films

This work reports on an experimental tunable electromagnetic bandgap array based on SrTiO/sub 3/ (STO) films grown on a Pt coated silicon substrate. The structure, which is a periodically loaded coplanar waveguide (CPW), has its first rejection band between 30 and 40 GHz. Without DC bias, the center of the rejection band is at 35.5 GHz and the insertion loss is 38 dB. At applied 20 V DC bias the center frequency tunes about 4% due to the change in dielectric constant of STO.