Designing Multi Beam Receiving and Transmitting Aperture LEO Space Communication Systems

2021 ◽  
Vol 26 (1) ◽  
pp. 64-73
Author(s):  
A.G. Efimov ◽  
◽  
S.A. Korneev ◽  
V.S. Matveev ◽  
V.V. Chistyukhin ◽  
...  
Keyword(s):  
Circular Polarization ◽  
Communication Systems ◽  
Space Communication ◽  
Energy Characteristics ◽  
Technical Parameters ◽  
Phased Antenna Array ◽  
Polarization Coefficient ◽  
Scanning Sector ◽  
Transmitting Antenna ◽  
Antenna Systems

In designing the receiving-transmitting active phased antenna array (APAA) an important problem is an achievement of the level of maximum outcome between the receiving and transmitting channels. In the work, the concept of building multi-beam receiving-transmitting antenna systems based on APAA has been considered. The criteria for selecting the type of emitter for an S-band antenna with the specified parameters have been presented. It has been shown that the use of a turnstile emitter based on the printing technology can reduce the complexity of manufacturing without compromising the technical parameters. In accordance with the requirements for volume of the tasks of APAA being designed the optimal geometric and electric characteristics of the turnstile radiator have been calculated. In designing the radiating apertures of the multi-element APAA the specifics of the dependence of their electric characteristics on the inter-element distance has been taken into consideration. To increase the circular polarization coefficient of the apertures being designed, the method of tearing apart of the radiator with further compensation of the obtained phase using the phase rotators APAA has been implemented. The estimates of the energy characteristics of the multi-element antennas with a given scanning sector for various inter-element distances have been given. To ensure the separation of the receiving and transmitting antennas the recommendations have been presented.

Actual issues of systematization of scientific knowledge on the conditions of shot in the forensic ballistics

2020 ◽  
Vol 2020 (3) ◽  
pp. 164-169
Author(s):  
Igor' Latyshov ◽  
Fedor Samuylenko
Keyword(s):  
Scientific Knowledge ◽  
Communication Systems ◽  
Production Method ◽  
Natural Phenomenon ◽  
Projectile Energy ◽  
Energy Characteristics ◽  
Shot Classification ◽  
Forensic Ballistics

In this research, there was considered a challenge of constructing a system of scientific knowledge of the shot conditions in judicial ballistics. It was observed that there are underlying factors that are intended to ensureits [scientific knowledge] consistency: identification of the list of shot conditions, which require consideration when solving expert-level research tasks on weapons, cartridges and traces of their action; determination of the communication systems in the course of objects’ interaction, which present the result of exposure to the conditions of the shot; classification of the shot conditions based on the grounds significant for solving scientific and practical problems. The article contains the characteristics of a constructive, functional factor (condition) of weapons and cartridges influence, environmental and fire factors, the structure of the target and its physical properties, situational and spatial factors, and projectile energy characteristics. Highlighted are the forms of connections formed in the course of objects’ interaction, proposed are the author’s classifications of forensically significant shooting conditions with them being divided on the basis of the following criteria: production from the object of interaction, production from a natural phenomenon, production method, results weapon operation and utilization, duration of exposure, type of structural connections between interaction objects, number of conditions that apply when firing and the forming traces.

scholarly journals Radar station with digital axisymmetric active phased antenna array as a promising direction for the development of surveillance radars

2017 ◽  
pp. 37-45
Author(s):  
M. V. Indenbom ◽  
R. L. Makhlin
Keyword(s):  
Service Life ◽  
Antenna Array ◽  
Phased Array ◽  
Time Increase ◽  
Promising Direction ◽  
Radar Station ◽  
Operating Modes ◽  
Phased Antenna Array ◽  
Mechanical Rotation ◽  
Antenna Systems

The purpose of the study was to build a surveillance radar station (radar) with an axisymmetric (i.e. cylindrical, conical, etc.), multibeam receiving-transmitting active phased array (APAR) and investigate its characteristics. The radar station makes it possible to shorten the surveillance time, increase the rate of updating information, provide flexibility in changing operating modes, increase the reliability and service life of a radar station as compared to a radar station with mechanical rotation of antenna systems. The radar station is compared with electronic circular scanning based on cylindrical, three- and tetrahedral APAR

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