The paper presents the theoretical study results of the dispersion characteristics of electromagnetic waves existing in antiferromagnetic (AFM) metamaterial. The AFM metamaterial consists of a transversely magnetized antiferromagnet, inside of which a two-dimensional periodic structure of thin conducting wires surrounded by insulators is placed. It has been established that the AFM metamaterial has two frequency ranges, in which there are backward waves, and the material pa-rameters of the medium are twice negative. The indicated areas are located in the terahertz range. Keywords: metamaterials, left-handed medium, antiferromagnetics, spin waves.

The paper presents the theoretical study results of the dispersion characteristics of electromagnet-ic waves existing in antiferromagnetic (AFM) metamaterial. The AFM metamaterial consists of a transversely magnetized antiferromagnet, inside of which a two-dimensional periodic structure of thin conducting wires surrounded by insulators is placed. It has been established that the AFM metamaterial has two frequency ranges, in which there are backward waves, and the material pa-rameters of the medium are twice negative. The indicated areas are located in the terahertz range.

The results of a theoretical study of the electrodynamic characteristics of fast and slow electromagnetic waves (EMWs) propagating in a metamaterial are presented. The metamaterial consists of a ferromagnetic film inside which a periodic lattice of thin metal wires is located. It has been established that the ferromagnetic thin-film metamaterial possesses the properties of a left-handed medium at frequencies of slow electromagnetic waves. It is shown that, in a ferromagnetic metamaterial, compared with a conventional ferromagnetic film, the cutoff frequencies of fast and slow EMWs shift to a higher frequency range, and EMWs themselves become strongly slowed waves.

We present the results of a theoretical study of the electrodynamic characteristics of fast and slow electromagnetic waves (EMWs) propagating in a metamaterial consisting of a ferromagnetic film inside which there is a periodic lattice of thin metal wires. The ferromagnetic thin-film metamaterial possesses the properties of a left-handed medium at frequencies of slow electromagnetic waves. In a ferromagnetic metamaterial, in comparison with a conventional ferromagnetic film, the cutoff frequencies of fast and slow electromagnetic waves shift to a higher frequency range and the electromagnetic waves themselves become very slow.