  A broad-band reflectionless channel which supports unidirectional wave
propagation originating from the interplay between gyrotropic elements and
symmetrically placed gain and loss constituents is proposed. Interchange of the
active elements together with a gyrotropic inversion turns the same structure
to a unidirectional absorber where incoming waves from a specific direction are
annihilated. When disorder is introduced asymmetric Anderson localization is
found. Realizations of such multi-functional architectures in the frame of
electronic and photonic circuitry are discussed.
