Magnetically and electrically controlled microwave interference pattern in a meta-interferometer

A specific selective effect of ferromagnetic and dipole resonances on an interference pattern in the range of $3$–$6$ GHz has been detected experimentally for the first time in a modified interferometer based on a waveguide T junction with a metastructure consisting of a ferrite plate and varactor-loaded dipole or ring conducting elements as a controlled beam splitter. A dependence of the shape, width, intensity, and frequency of an interference band on the magnitude and sign of a static magnetic field $H$, the relative position of ferromagnetic resonance and band, and the electric voltage $V_{\mathrm{DC}}$ on varactor diodes has been observed. The nonreciprocity of microwave transmission in interference stop bands characterized by change in the transmission coefficient $T$ at the inversion of $H$ has been revealed. Nonreciprocity increases at the excitation of ferromagnetic resonance near a band. In this case, a jump of $T$ by two orders of magnitude to a level of a passband is observed with the reversal of the magnetic field $H$. The sign of nonreciprocity depends on the relative position of ferromagnetic resonance and the stop band and can change at a small variation of the magnitude of $H$. The selectively controlled narrowing of the nonreciprocal band by several times, as well as the shift by $0.2$ GHz, is observed with the variation of $V_{\mathrm{DC}}$ in the range of $0$–$10$ V.