Vol 21, No 1 (2018)
- Year: 2018
- Articles: 8
- URL: https://journals.ssau.ru/pwp/issue/view/369
Articles
The spatial characteristics of a four-wave converter of radiation in multimode waveguide with resonant nonlinearity
Abstract
The quality of wave-front reversal has been studied at degenerate four-wave interaction in two-dimensional multimode waveguide with resonant nonlinearity using the Point-Spread Function (PSF) method. It has been shown that over time the PSF-module width, defined by paraxial waveguide modes, decreases, reaching a steady value, slowly varying with increasing the pump intensity. The PSF-module width first increases and then decreases with the increasing of number of pump wave mode when the coincidence of the numbers of single-mode pump waves.
4-11
12-16
Comparative analysis on sudden ionospheric disturbance
Abstract
The effect of sudden ionospheric disturbances on the phase of the received signal on four paths is considered. The experimental data were obtained from the phase of the signals by the radio navigation system Omega. Paths are almost the same length. The transmitters are located at two points. It is shown that the phase deviation of the received signal obeys the Poisson distribution. It is necessary to take into account the seasonal variations of the electron density.
17-22
To the question of using the cognitive technology of «white spots» of the TV range in VANET networks
Abstract
The article discusses problems transmission of the messages of road safety in the VANET network in the broadcast mode via radio channels between two moving cars. The problem caused by the low location of the transmitting and receiving antennas above the earth’s surface. The waves used in VANET channel with a frequency of 5.89 GHz, due to the weak ability of diffraction, experience significant attenuation up to the complete blocking line of sight. Obstructions of the normal conditions of reception of the messages of road safety causes an increase in delivery time and probability of reception of these messages. To solve the problem of ensuring reliable delivery of the messages of road safety is proposed to add transmission SM in the channel of 5.89 GHz transmission in the UHF TV band for cognitive technologies «white spaces». Wave propagation in this part of the spectrum have a better ability to diffraction, the smaller the attenuation depending on the distance between the transmitter and the receiver, which contributes to the effective delivery of the messages of road safety in the network of VANET.
23-29
Development of algorithms for predicting quality indicators and reliability of elements of onboard radio engineering systems with little informative parameters
Abstract
It is shown that it is expedient to use extrapolation methods for individual forecasting of quality indicators and reliability of elements of onboard radio engineering systems with little informative parameters. Algorithms for predicting quality indicators based on quasi-deterministic models are offered. It is established that the best results of forecasting are achieved using logarithmic models. The reduction of nonlinear models to linear ones is provided. Algorithms are recommended for use in the training and examination stages.
30-37
Technology and technique of the CMOS-chip learning experiment
Abstract
The technique of the learning experiment of the chips with a CMOS structure is considered. The analysis of the constructive-technological features of the 765 series chips have carried out. The connection circuits and schemes of the main parameters measurement during the learning experiment are proposed. A choice of methods and means for the informative parameters control in the investigation tests is studied. The process of the sample size selecting is described. An approach to the development of the routine investigation tests is defined.
38-47
Methodical bases of functioning of the system model information and telemetric ensuring starts of rockets of space appointment
Abstract
Defines the basic structural-elements of functioning of a system of information telemetry ensuring starts rockets of space appointment. The contents of information processes in the system of information telemetry ensuring starts rockets of space appointment. Highlighted factors in the model functioning sieve. Formed functional dependence parameters characterizing the degree of attainment of the objectives of the system parameters, inputs and system state settings.
48-53
The generator of monochromatic self-oscillations in discrete time
Abstract
For design of generators of self-oscillations in discrete time it is offered to use harmoniously linearized models of self-oscillatory systems of Thomson type. Estimates of speed and instant power of oscillations, necessary for these models, are carried out on the basis of a formula of numerical differentiation of harmonious signals with the known frequencies. It is shown that within such approach in discrete time it is possible to realize the nonlinear systems generating strictly monochromatic self-oscillations.
54-57
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