V. V. Biryukov - Ph.D. (Eng.), Associate Professor of Department of Physics and Technology of Optical Communication, Institute of Nuclear Energy and Technical Physics, Nizhny Novgorod State Technical University n.a. R.E. Alekseev. E-mail: physics@nntu.nnov.ru
V. A. Grachev - Postgraduate Student, Department of Physics and Technology of Optical Communication, Institute of Nuclear Energy and Technical Physics, Nizhny Novgorod State Technical University n.a. R.E. Alekseev
A. S. Raevskij - Dr.Sc. (Phys.-Math.), Professor, Head of Department of Physics and Technology of Optical Communication, Institute of Nuclear Energy and Technical Physics, Nizhny Novgorod State Technical University n.a. R.E. Alekseev
V. V. Shcherbakov - Ph.D. (Eng.), Associate Professor of Department of Physics and Technology of Optical Communication, Institute of Nuclear Energy and Technical Physics, Nizhny Novgorod State Technical University n.a. R.E. Alekseev

Planar slot antenna arrays (SAA) are used for receiving low-intensity relict cosmic radiation in terahertz range. Particularly, the measurement of the polarization characteristics of the received signal is important. The manufacture of such antenna systems and their experimental study directly in the terahertz frequency range is a very complex technological and technical problem. To solve it, the principle of electrodynamics similarity is used: having fulfilled design of such antenna array in the microwave range, it is possible to extend the results on a higher frequency range. Different receiving elements of the slot antenna array were investigated. It was experimentally established that a single slot has the lowest coefficient of cross-polarization. Array elements are arranged on a dielectric substrate of finite size. Frequency dependence of the transmission coefficients between slots of the antenna array, the frequency dependence of the input impedance and VSWR of central element the antenna array were obtained by simulating in the CAD HFSS. To assess the influence of the antenna array substrate surface waves on the cross-polarization coefficient various boundary conditions were considered. The best polarization discrimination was achieved with substrate ends covered with the radio absorbing material. The SAA main characteristics, the comparison results of experimental and calculated data are shown. Recommendations for creating SAA with the desired characteristics are given.