Boundary problem of excitation of spiral wire system on a plane chiral substrate

Microwave devices built on the basis of plane logarithmic spirals, like a printed spiral antenna, are of significant interest due to potentiality of widening the operating frequency range. For obtaining unidirectional radiation, they are used with a screen or a resonator filled with a magnetodielectric, due to mechanical considerations or for reducing the antenna size. The influence of a wire system and chiral material used instead of a dielectric, on the electromagnetic characteristics, is investigated