HIGH-Q RADIOFREQUENCY STRUCTURES USING ONE-DIMENSIONALLY PERIODIC METALLIC-FILMS

High-Q structures are very interesting theoretically, and very importa nt practically, for a variety of engineering applications in communica tion systems. We address the issue of designing a thin-film metal stru cture of reflectivity higher than the intrinsic reflectivity of the bu lk metal itself. We study a finite array of planar conducting layers o f arbitrary thickness periodically placed an arbitrary distance apart, and we arrive at an exact analytical formula for the reflection and t ransmission coefficients. These structures are equivalent to a one-dim ensional metallic photonic bandgap (PBG) system. We apply our formulas to the microwave regime and fully explore the system's three-dimensio nal parameter space, consisting of the number of layers, their thickne ss, and their spacing. We find very significant enhancements of the ra dio frequency-Q, relative to the bulk metal, in narrow regions of the parameter space.