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Journal of the Russian Universities. Radioelectronics

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No 1 (2017)
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RADIO ELECTRONIC FACILITIES FOR SIGNAL TRANSMISSION, RECEPTION AND PROCESSING

5-12 562
Abstract
An adaptive transversal filter capable of suppressing broadband jams and receiving broadband signal simultaneously is considered. Signal processing algorithm using power vector basis is proposed. Regularized estimation weight vectors for a limited number of samples of the input process that can be both larger and smaller than the number of filter taps are obtained (case of short sampling). Simulation results showing high efficiency of signal processing algorithm are given.
12-16 454
Abstract
This paper deals with the radio source type detection algorithm with a complicated time-frequency structure. The algorithm is based on splitting training data classes into sub-classes, and using them for making a decision about the type of radio source. Result of testing on simulated data is presented.

TELEVISION AND IMAGE PROCESSING

17-28 469
Abstract
The problem of detection and localization of various size and shape small-extended objects in electronic surveillance systems using synthetic aperture radar, lidar, infrared and television cameras is discussed. An intensive and non-stationary background is described as the main difficulty in processing. This problem is solved using oriented filtering, adaptive thresholding and morphological analysis. Improved method is proposed for the adaptation of detection threshold based on the analysis of isolated fragments remaining in the image after thresholding.

ELECTRODYNAMICS, MICROWAVE ENGINEERING, ANTENNAS

29-35 495
Abstract
The characteristics of different architectures antenna arrays with switchable radiation pattern (RP) are investigated. The results of design and development of S-band antenna systems with switchable RP based on planar emitters are presented. The obtained solution minimizes the size and the irregularity of RP in the azimuth plane while providing the required antenna gain. The results of measurements of a prototype are given that demonstrate the possibility of Wi-Fi router input signal increasing up to 10 dB compared to standard antennas.
35-39 463
Abstract
The various methods of antenna electrical tuning for mobile handsets working in several LTE frequency bands are described. The PIFA-type antenna containing high and low frequency branches is proposed. A tuning element is connected to the low-frequency branch. The proposed antenna operates at one of four low-frequency bands depending on the tuning element switching states, keeping tuning to the high-frequency band. A digitally tunable capacitor, a varactor and a p-i-n-diode are used as a tuning element. Comparison of simulation results demonstrates that the p-i-n diode provides the best performance showing antenna radiation efficiency 36…60 % in the low frequency bands and 78 % in the high frequency band. The antenna simulation is performed by RFS computer code.

TELECOMMUNICATION SYSTEMS, NETWORKS AND DEVICES

40-44 599
Abstract
User session extraction from network traffic data is considered. Statistical analysis of inter-session times of infocommunication network link was performed. Q-exponential distribution was proposed to describe the inter-session times distribution. Aggregated traffic model of infocommunication network link based on superposition of short-term traffic fragments data was suggested. The aggregated traffic model was verified by means of empirical traffic data.

RADAR AND NAVIGATION

45-48 429
Abstract
Several scenarios of wireless time scales synchronization for promising local positioning system are reviewed. A way to eliminate the frequency drift when measuring the object coordinates in the result of the reference generators nonidentity is proposed.
49-55 425
Abstract
Building of user interface of the local positioning system is considered. It is shown that to achieve centimeter positioning accuracy the application of ultra-wideband signal technology with separate transmission of data message is required.

MICROWAVE PHOTONICS

56-62 605
Abstract
A method of calculation of resonant frequencies and thus free spectral range of high-Q dielectric disk resonators with whispering gallery modes is proposed. The method is based on application to the dispersion equation derived for a dielectric cylinder with unlimited length, dimensional quantization, due to the requirement of phase balance for the standing waves in the resonator. The simplified expressions suitable for calculation of optical microcavities used in the devices of radio photons are obtained.

MICROWAVE ELECTRONICS

63-73 465
Abstract
The construction principle of simulator-analyzer is proposed providing simulation modeling of amplifiers and oscillators in coaxial microwave measurement chain according to their technical specifications, followed by measurement of complex load reflection coefficients of the active component of the devices for their further development in microstrip design. Mathematic model of simulator-analyzer as well as mathematic model of its calibration is presented. Analysis method of active component stability in the area of its complex load reflection coefficients is considered that facilitates the choice of the loads and the most active component in simulation of amplifiers and oscillators. In addition, the possibility of using the simulator-analyzer for measuring complex reflection coefficients at the input and the output of the loaded active component is described, as well as measurement of its complex transmission coefficients which together with the measured complex load reflection coefficients allow to determine S-parameters of the analyzed component it will have when included in a micro strip line.

MEDICAL DEVICES, ENVIRONMENT, SUBSTANCES, MATERIAL AND PRODUCT

74-79 466
Abstract
The paper presents the program module that estimates the probability of complications after the bone marrow transplantation. The shown approach is based on a logistic regression. The medical database containing the records of 155 patients aged from 5 to 21 is used. The program module contains a detailed graphical representation of the results in the form of a ROC curve, the calculated values of true and false predictions as well as likelihood ratio of the obtained values. The areas of reliable and unreliable predictions as well as the area where predictions are impossible are highlighted on the chart.


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ISSN 1993-8985 (Print)
ISSN 2658-4794 (Online)