Electrical Filters Containing Multistage PBG Resonators

Electrical filters of a recently invented type are designed and constructed as transmission lines into which multistage photonic-band-gap (PBG) structures are incorporated. As used here, “transmission lines” refers to any or all of the standard electrical media, including coaxial cables, microstrips, and the like, used for propagation of electromagnetic waves along enclosed or well defined paths. The term “electrical filters” is used here in a conventional sense, denoting any of a variety of systems or components that block propagation of signals in certain frequency bands (stop bands) and/or support propagation in other frequency bands (pass bands). The PBG structures used in this invention can be any of a variety of dielectric or electrically conductive structures, containing precise periodic or quasiperiodic arrays of holes or other features that can be tailored to obtain desired stop bands.