The design documentation was developed, the layout was made, and an experimental study of the direction-finding receiver was conducted. A functional diagram and a description of the design are given. The method of the experiment is given. Shows the achievement of the following parameters: operating frequency range: centimeter; the dynamic range of the signals at the entrance 48 dB; the duration of the received pulses is not less than 0.1 µs; the irregularity of amplitude-frequency characteristics of not more than 5 dB.

Keywords: direction finding receiver, logarithmic receiver, amplitude-frequency response, amplitude response, dynamic range

In July and August 2019, the Grott ground penetrating radar was used as part of the field work of the Russian Arctic National Park, a federally funded institution, to survey areas polluted by oil products on Alexandra Island in the Franz Josef Land Archipelago. The results obtained are discussed and conclusions are drawn about the prospects of using the method of ultra-wideband electromagnetic sounding to solve environmental problems in the permafrost zone in the Arctic region.

Keywords: national park, Arctic, pollution, waste, soil, rock, georadar, ecosystem, sounding, radarogram, infiltrate

This study investigates possibilities for identifying additional deposits of polymetallic ores based on geophysical studies that use ground-penetrating radar (georadar). Such studies can render a deposit significantly more attractive from an economic standpoint. Experimental methodological work was carried out to compare the geological data of preliminary exploration and georadar exploration with GROT 12 georadars.

Keywords: ground-penetrating radar, radargram, geological section, profile, anomaly, ore body, exploration, video pulses

The article describes the correlation between the signal edge amount of sounding pulse and small irregularities detection in environments with dispersion. The analysis of experimental data on effective bandwidth of decameter waves spreading on the route Moscow-Ekaterinburg and results of wideband ground-penetrating radar sounding in natural environments with high dispersion gives the opportunity to experiment on surface, vertical and backward-inclined sounding. It is reported that the use of wideband electromagnetic pulses is perspective trend of progress in sounding of natural environments.

Keywords: electromagnetic sounding, decameter waves, electromagnetic pulses, small irregularities, permittivity, ground-penetrating radar sounding, dispersion, natural environment, vertical sounding, spectral form, ionosphere

A novel compact easy-to-manufacture design of 20 dB directional coupler has been proposed for a high power operation within frequency band 4-12 GHz. In order to obtain the broad band frequency response a three-section asymmetric coupled strip-line directional coupler has been chosen. The periodic structures are introduced on the outer edges of coupled strip-lines for the wide-band compensation of the difference between phase velocities of even and odd modes. The successfully fabricated and tested coupler shows high electrical performances. The proposed 20 dB directional coupler provides within frequency band 4-12 GHz the coupling characteristic imbalance 0.5 dB, isolation 35 dB, directivity 15 dB and VSWR<1.35. The allowable input power of directional coupler is up to 100 W. The coupler dimensions are 39x35x26 mm.

Keywords: directional coupler, coupled strip-lines, even and odd modes, periodic structures, phase velocity of modes, lines with side coupling

A possibility to observe synchronous emission of distant galaxies' ionized hydrogen by extended disks is discussed in this work. It is shown that the most preferred wavelength range from the viewpoint of observation success rate is decameter range on low frequency limit allowing for such observations: 3 MHz. It is shown that high brightness temperature of noise in this frequency range forces to consider only a possibility of interferometer observations. This mode allows to detect a signal from extended ionized galactic disks located within the Local Group. The work also provides an assessment of the capacity to measure the parameters of these disks by means of raying them with radiation from pulsars and measuring dispersion of signal.

Keywords: HII and HI regiones, synchrotron radiation, radio emission galaxies, brightness and noise temperature, radiointerferometry, decameters interferometer

A calculation module for electromagnetic field calculation of an energy stream density in arbitrary points is developed.  This module is counting from any quantity emitters. Orientation properties of antennas are taken into account by the emitters. The module is calculated for an orientation diagram of various type antennas. The module is allows counting various types of emitters in horizontal and vertical planes. The module is realized as fully operational program. This application deals with the algorithm counting energy stream density with vector maps. This program is making calculations restriction areas for building and sanitary-protective areas for mobile companies and TV and radio stations.

Keywords: Calculation module, electromagnetic irradiation, energy stream density, aperture sources, emitters, restriction areas for building, sanitary-protective areas

The work is focuses on the determination of the attenuation factor of electromagnetic radiation when applied in soils with different physical properties as a criterion for assessing the depth of Ground-penetrating radar (GPR) method. The measurements were performed using a tunable coaxial resonator which frequency range coincides with one normally used in the practice of GPR. The attenuation factor of a sample of soil placed in a cavity is determined by the shift and width of the resonance line. Advantage of this method is the preservation of soil structure during the measurement.

Keywords: ground-penetrating radar, properties of soils, attenuation factor.