About electrical control of nonreciprocity of microwave transition in metastructures

V. S. Butylkin, G. A. Kraftmakher, Yu. N. Kazantsev
V.A. Kotel’nikov Institute of Radio-engineering and Electronics of RAS, Fryazino Branch

The paper is received on December 15, 2014

Abstract. A possibility of electric control of microwaves passage nonreciprocity (up to its inversion) is under investigation on the sample of a nonreciprocal proto-device consisted of a varactor loaded dipole and ferrite piece. Phenomenon of nonreciprocity in structures with transversely magnetized ferrites is caused by different absorption of waves which have the magnetic field sense of rotation coincident with direction of the ferrite magnetic moments precession and opposite it. That is why microwave magnetic field behaviour in the neighborhood of a dipole is regarded. This magnetic field is a result of the incident and scattered waves superposition. It is shown that whole magnetic field is elliptically polarized in common case. During the dipole own frequency re-tuning the phases of its current and scattered wave are changed. Hereupon the magnetic field sense of rotation can change. This change results in the nonreciprocity inversion. In contrast to traditional methods there is no need to re-magnetize ferrite for switching nonreciprocity. One can get re-tuning of the dipole frequency by alteration of a bias voltage applied to varactor. experimental investigation of a structure with varactor-loaded dipole “Butterfly” has demonstrated inversion of microwave nonreciprocity. The proposed metastructures open up wide prospects for applications in the field of information technologies. These metastructures may form the basis for manufacturing fast controlled and switchable nonreciprocal microwave systems.

Key words: microwave, nonrecipocal transmission, switching, electrical control, ferrite, varactor.