Perfect co-circular polarization reflector: A class of reciprocal perfect conductors with total co-circular polarization reflection

We establish a general class of reciprocal perfect conductors, namely perfect co-circular polarization (CP) reflector, from which the reflected waves are completely co-polarized when a circularly polarized electromagnetic (EM) wave impinges on it, in contrast to a conventional perfect conductor like a perfect electric conductor (PEC), a perfect magnetic conductor (PMC) or their interpolated version as a perfect electromagnetic conductor (PEMC). We discuss the impedance boundary conditions and the reflection characteristics of the perfect conductors, including perfect co-CP reflectors and perfect cross-CP reflectors, in terms of a circularly polarized EM wave. We also discuss the realization of one of the perfect co-CP reflectors approximated by coating a layer of anisotropic, yet lossless and reciprocal, material on a PEC. In addition, we discuss its realization using metamaterial structures.