Reversal of Microwave Propagation Nonreciprocity in Metastructures by Voltage Application under Ferromagnetic Resonance Excitation near Resonance of Dipole or Chiral Elements

摘要

Ferrite plate/varactor-loaded conductive resonance elements (chains or single element) metastructures are investigated experimentally in waveguide to achieving voltage controlled inversion of sign of the nonreciprocity S of microwave propagation. Dipoles of various shapes (butterfly, loop, snake, double split rings) with different type-varactors have been investigated. The metastructures show unique magnetically and electrically controlled nonreciprocal effects under coupled ferromagnetic resonance (FMR) in ferritc and resonance in dipoles (DR). Inversion of sign of δ occurs by the application of a bias voltage to a varactor when resonance frequency of DR passes through the FMR frequency as a result of which reversal of sense of rotating clliptically polarized h-field takes place. Usually inversion of nonreciprocal propagation of microwaves in ferrite is implemented by reversal of magnetization direction as a result of which reversal of sense of spins precession occurs.