ABSTRACT
Electromagnetic properties of metamaterials (MTM) are defined by the properties of inclusions and by their positioning in the matrix. The inclusions forming many MTM are resonant and their resonances are in the frequency range where the distance between them can be a rather small fraction of the wave-length in the host medium. Frequency dispersion in MTM formed by electrically small inclusions is very strong, since such particles can be effectively excited only in the vicinity of their resonant frequencies. Also, spatial dispersion effects can be strong in MTM, because inclusions or distances between them are often comparable in size with the effective wavelength in the composite. Since the wires are usually quite long, spatial dispersion is very strong even at very low frequencies. However, in simple wire media this spatial dispersion holds only if the wave propagates obliquely with respect to the axes of wires.
