Аннотация:This article is devoted to the study of the possibilities of increasing
the spectral efficiency in MIMO systems by using antennas with substrates of
biisotropic and bianisotropic chiral metamaterials and various types of fractal
emitters. Fractal structures in the form of a Sierpinski triangle, Koch and Gilbert
curves, as well as a dipole triangular antenna of complex configuration were
used. The method of designing a chiral metamaterial based on helices, which
provides the implementation of the specified values of resonant frequencies, is
shown. The spectral efficiency was calculated by using one of the variations of
the Shannon formula, which includes a complete matrix of Z-parameters calculated
using electrodynamic modeling methods based on integral equations. It
is shown that the use of such antennas with the fractal geometry of the emitters
located on chiral substrates allows to reduce the mutual influence between the
emitters, and, in turn, to increase the spectral efficiency in several frequency
ranges compared to traditional solutions.