Begell House Inc.
Telecommunications and Radio Engineering
TRE
0040-2508
76
5
2017
THE STATE-OF-THE-ART OF DIPOLE, DIELECTRIC, AND PLASMA ANTENNAS IN THE CONTEXT OF HISTORICAL EVOLUTION OF ANTENNA SYSTEMS
371-399
10.1615/TelecomRadEng.v76.i5.10
V. V.
Ovsyanikov
Oles Honchar Dnipro National University
72, Gagarin Av., Dnipro, 49010, Ukraine
dipole antennas
helical antennas
dielectric antennas
plasma antennas
current distribution on the antenna
input impedance
voltage standing-wave ratio
efficiency
radiation pattern
The present paper analyses the period of initiation and development of science and technology of dipole antennas with reactive and complex loads, microwave dielectric and plasma antennas, as well as dipole and helical electrically-small antennas, multi-frequency, broadband and pin
antennas, loop antennas and antenna arrays with improved radiation pattern. The methods of evaluation and calculation of basic antenna parameters such as current distribution, input impedance, voltage standing-wave ratio, efficiency, radiation patterns and polarization characteristics are under study. The results of calculations and the design features of these antennas are discussed.
COMPARATIVE STUDY OF BSA AND FA FOR SYNTHESIS OF COSECANT SQUARED PATTERN
401-416
10.1615/TelecomRadEng.v76.i5.20
Hemant
Patidar
NIT Durgapur
G. K.
Mahanti
National Institute of Technology Durgapur,
Mahatma Gandhi Avenue, Durgapur 713209, West Bengal, India
backtracking search algorithm
cosecant squared pattern
FEKO
firefly algorithm
inverse fast Fourier transform
side lobe level
Comparative study of two evolutionary algorithms namely backtracking search algorithm (BSA) and firefly algorithm (FA) has been described in this paper for synthesis of cosecant squared radiation pattern in linear antenna array. BSA and FA have been used with the inverse fast Fourier transform (IFFT) to reduce the computational time significantly. Performance of the above algorithms for synthesis of shaped beam pattern are compared here in
terms of different antenna parameters like side lobe level, maximum reflection coefficient (S11) in dB, ripple as well as statistical parameters such as global best fitness value, worst fitness value, mean and standard deviation. To obtain the cosecant squared pattern, voltage excitation and the static phase shift of the linear array elements are taken as the optimizing parameters and BSA and FA is used as the optimizing algorithms. In addition to it, obtained results from simulation of both the optimization algorithm on MATLAB is also validated by results obtained from FEKO analysis. Mutual coupling has been considered between the parallel dipole antennas. Work is demonstrated by twenty four element linear array of parallel dipole antennas for synthesis of shaped beam pattern.
INTEGRATED METHOD FOR DYNAMIC REPLICATION OF SERVICES IN SOFTWARE-DEFINED NETWORKS
417-432
10.1615/TelecomRadEng.v76.i5.30
E.
Tkachova
Kharkiv National University of Radio Engineering and Electronics, 14, Nauka Ave, Kharkiv, 61166, Ukraine
A. T. Abu
Jassar
Irbid National University, Jordan
Amman-Irbid International road, Irbid, 21110, Jordan
dynamic replication
response time
Software-Defined Networking
reliability
service provision
The article is devoted to development of a complex method for dynamic replication of services in software-defined networks. Review of existing replication methods that have found a wide application in distributed computing networks is proposed, main advantages and disadvantages of these methods are given. The method is proposed on the basis of the results of this analysis, which involves solution of the following tasks: evaluation of popularity of the service and choice of launching of the replication operation based on the replication threshold value; calculation of the optimal number of replicas and their placement on the computing
nodes; formation of the decision to remove a replica.
EVALUATION OF THE FREQUENCY SCALING PREDICTION TECHNIQUES USING EXPERIMENTAL DATA
433-442
10.1615/TelecomRadEng.v76.i5.40
B. B.
Jimoh
Electrical & Electronics Engineering Department, University of Ilorin,
P.M.B.1515, Nigeria
A. Y.
Abdulrahman
Electrical & Electronics Engineering Department, University of Ilorin,
P.M.B.1515, Nigeria
A. J.
Falade
Electrical & Electronics Engineering Department, University of Ilorin,
P.M.B.1515, Nigeria
O.
Oniyide
Electrical & Electronics Engineering Department, University of Ilorin,
P.M.B.1515, Nigeria
S. O.
Zakariyya
Electrical & Electronics Engineering Department, University of Ilorin,
P.M.B.1515, Nigeria
T. A.
Rahman
Wireless Communication Center (WCC), Universiti Teknologi Malaysia
(UTM), Malaysia, Johor, Malaysia
frequency scaling technique
rain attenuation statistics
huge
receiver margin
tropical climates
Long-term statistics of measured slant-path attenuation above Ku-band are severely scarce in the tropical climate; due to the huge capital costs involved in the experimental setup and receiver margin required, which is very difficult to obtain by using a spectrum analyzer. The received signal becomes masked at heavy rain rates owing to the high noise level therefore the signal level could not be monitored. Therefore the frequency scaling technique is a useful and
powerful tool for estimating the attenuation at a desired frequency when the measurement data are available at a particular, usually lower, frequency. The results of measured rain attenuation from a tropical climate in Malaysia were used to investigate the performance of a few frequency scaling techniques. The experimental results were obtained from the four experimental microwave links (15, 22, 26, and 38 GHz at a separation distance of 300 m) installed at UTM campus, Johor Bahru, Malaysia. The results of the statistical analysis show that the ITU-R model is the most suitable for the lower frequency (26 GHz), while the Drufuca model is most suitable one for the higher frequency (38 GHz).
APPLICATION OF TIME-FREQUENCY ANALYSIS TO NON-STATIONARY AND MULTICOMPONENT SIGNALS
443-459
10.1615/TelecomRadEng.v76.i5.50
A. V.
Totsky
National Aerospace University (Kharkiv Aviation Institute), 17, Chkalov St., Kharkiv, 61070, Ukraine
J. T.
Astola
Tampere University of Technology, Signal Processing Laboratory, P. O. Box 553, FIN-33101, Tampere, Finland
O. A.
Polotska
V. Karazin National University of Kharkov,
4, Svoboda Sq., Kharkiv, 61077, Ukraine
time-frequency analysis
time-frequency distribution
bispectral estimation
Wigner-Ville distribution
autoregressive model
Wigner-bispectrum
frequency resolution
noise immunity
radar backscattering
In this paper, four different approaches to time-frequency analysis performed by using parametrical and non-parametrical bispectral estimation, as well as the Wigner-Ville and Wigner-bispectrum techniques are considered, studied and compared between each other. Frequency resolution and noise immunity have been investigated for different time-frequency distributions by the computer simulations. Results of computer simulations are represented
both for multi-component signal models and radar backscattering signals experimentally recorded for moving radar object in the form of walking human. It is demonstrated that the parametrical bispectrum-based technique provides smallest distortions in time-frequency
distributions for the non-stationary multicomponent signals though, at the same time, it inferiors a few to the Wigner-Ville distribution in noise immunity.