Tunable electromagnetic bandgap performance of coplanar waveguides periodically loaded by ferroelectric varactors

To achieve tunable electromagnetic bandgap) (EBG) performance, ferroelectric varactors are considered, in LC circuits, for periodically, loading coplanar waveguides (CPWs). Asymmetric or symmetric timing of the bandgap, width maybe achieved by changing the capacitance of the varactors in the LC circuits. To validate this concept, tunable EBG arrays based on silicon substrate CPWs, including thin film SrTiO3 (STO) varactors, are fabricated and tested experimentally. The EBGs are designed so that the first band gap starts between 20 and 30 GHz. Up to 10% tuning is achieved, under 20-V DC applied bias in the EBG structures. (C) 2003 Wiley Periodicals, Inc.