Kharkov National University
V.N.Karazin
Main / Vestnik KhNU /Radiophysics and Electronics
 
Main
 
Edit. Board
 
For authors
 
Numbers
 
Authors
 
Titles
 
Keywords
 

1.  Millimeter wave rotational spectrum of the lower excited vibrational states of CH3CF2Cl
O.I. Baskakov, V.V. Ilyushin, E.A. Alekseev
molecule, rotational spectrum, Interacting states, Hamiltonian, HCFC-142b
Vestnik KhNU 712 Pages. 3-9

The millimeter rotational spectrum of CH3CF2CI has been investigated. The rotational, centrifugal distortion and quadrupole coupling parameters have been determined for the vibrational states with energies below 600 cm-1. Parameters of the ground and 111, 171, 181, 171181 and 111 states have been obtained for both chlorine isotopic species. In addition, the 1111, 182, 101, 161, 91 and 111181 vibrational states have been studied for CH3CF235C1 molecule. It was found the interaction between 101 and 161, and 91 and 111 181 couples. The transition frequencies calculated with the parameters obtained coincide with the measured ones within experimental uncertainties.



2.  Telemetering methods, devices and their application in vertebrology
S.N. Kulish, O.Y. Kagan
radiotelemetring research, transmitter, radio channel, Implant devices, spine, Impellent segments
Vestnik KhNU 712 Pages. 33-36

In the given job the review and the analysis of existing telemetering methods of research and diagnostics of various diseases in medicine is resulted. It is offered to use means of radiotelemetering research for registration of mechanical parameters arising on contact and lateral surfaces of impellent segments of a backbone. The block diagram of multichannel telemetering system is resulted and the basic requirements shown to this system are described



3.  Scattering electromagnetic waves by coupling aperture of electrodynamic volumes in presence of finite sizes impedance body
M.V. Nesterenko
Impedance vibrator, narrow slot, distributed surface impedance, rectangular waveguide
Vestnik KhNU 712 Pages. 47-51

Systems of integral-differential equations concerning surface equivalent magnetic and electrical currents which are excited with impressed sources of electromagnetic field in the coupling aperture of electrodynamic volumes and in the finite sizes impedance body have been obtained. The approximate analytical solution of the equations system for the narrow transverse slot in the broad wall of rectangular waveguide with the thin impedance vibrator was represented. Also theoretical and experimental graphs of electrodynamic characteristics of such structure in dependence on the wavelength in the base oscillations band the waveguide was represented



4.  Integral representation of green function in parallel-plate and rectangular waveguide, and in resonator as well
V.A. Katrich, F.S. Novokhatsky
waveguides, Green function, fundamental solution, radial function, elliptical teta- function, Image method, calculus of residues, Integral transformation, grating, formal variative
Vestnik KhNU 712 Pages. 67-70

The known results connected with Green function representation by elliptical theta-function are generalized. New representations of Green function for some widely used types of waveguides are obtained. Earlier, these Green functions are presented either in form of series with nonuniform convergence or in form of integrals containing Hancel functions, which are reduced to asymptotic expressions in far zone. On this work integral representations of Green functions are obtained for Cases where the quadrature formula exists. The method of analytical continuation with parameter is applied



5.  Features of forming patterns of planar antennas arrays
A.A. Bulgakova, N.N. Gorobets, V.A. Katrich, V.A. Lyashenko
planar arrays, pattern, sidelobes, radiator elements, Interference maximums triangular grid
Vestnik KhNU 712 Pages. 71-75

Computer analysis results of an influence of a radiating aperture form of the planar array on its pattern have been presented. It is shown that there is dependence of levels of interference lobes and also near and far sidelobes of pattern in one of main positions of observation planes on number and radiators in plane which is orthogonal to main observation plane



6.  The spectrum of current oscillations of Gunn diodes with the impact ionization in moving domains
D.V. Pavlenko, E.D. Prokhorov
Gunn diode, Impact ionization, UHF-noise
Vestnik KhNU 712 Pages. 123-126

The results of the numerical simulation of the GaAs Gunn diode with electric field strengths, enough for development of the impact ionization in the moving high-field domains, are presented. The form of current oscillations and frequency spectrums is in good agreement with experimentally measured data. It is shown that the Gunn diode, operating under conditions of the impact ionization, may be used as a source of wide spectrum UHF-noise



7.  On the directive gain of the self-focusing antenna
Ya.S. Shifrin
directive gain, self-focusing antenna, Inhomogeneities, structure function
Vestnik KhNU 756 Pages. 11-17

The influence of the atmospheric inhomogeneities on the directive gain of the self-focusing antenna array (SFAA) at description of the atmosphere by the theory of the local-isotropic turbulence is considered. There are analyzed two cases when a size of the SFAA subaperture is respectively more or less than the turbulence scale of the medium. It is shown mat the results of the meat directive gain estimation for the two cases are well conformed qualitatively with the analogous estimates obtained at the atmosphere description wife the help of the Gaussian correlation function of its refractivity index



8.  GAUSSIAN EXPANSIONS FOR RADIATION PATTERN OF AN OPEN-ENDED LINE WITH IMPEDANCE BORDERS
A.P. Udovenko
aperture distribution, Impedance border, orthogonal functions, diffraction integral, feed
Vestnik KhNU 756 Pages. 87-90

Near-field and far-field two-parameter expansions in terms of Laguerre-Gaussian orthogonal basis functions are proposed, which take into account the effect of impedance feed borders. The expansions enable the feed characteristics on a base of lines with impedance borders to be calculated in wide frequency region. Radiation intensity distributions for the open-ended two-layer metal-shielded dielectric waveguide in a nonresonance regions of surface impedance varying, relative errors of expansion truncations, comparison with experimental data are presented



9.  Amplitude and noise features of detectors a mm of range of lengths of waves on base of contacts a metal-semimetal BiSb
O.N. Sukhoruchko, V.T. Plaksiy, E.D. Prokhorov, A.V. Dyadchenko
contact metal-semimetal BiSb, power zones, contact a metai-semimetal BiSb, millimeter range of lengths of waves, relative noise temperature, Influence of displacing and resistances of contacts on sensitivity
Vestnik KhNU 756 Pages. 113-117

In work are brought results of analytical and experimental thermoelectrical detector study with the point contact a metal-semi-metal BiSb. Determined relative noise temperature, as well as influence of displacing and resistances of contacts on the sensitivity in 8 mm range of waves.



10.  THE H10 WAVE SCATTARING BY THE THIN VARIABLE RADIUS IMPEDANCE VIBRATOR IN A
Nesterenko, E.Y. Belogurov, V.A. Katrich, V.I Kijko
Impedance vibrator, biconical vibrator, distributed surface impedance, rectangular waveguide, the method of induced electromotive forces
Vestnik KhNU 806 Pages. 14-17

The problem of the fundamental wave scattering by the thin variable radius impedance vibrator arbitrary situated in a rectangular waveguide was solved. Calculations were carried out and energetic characteristics of such structures were plotted


Download >>


11.  The influence of a dispersion and losses to the interaction of impulse signal with the model of the biological tissues
O.N. Zheryobkina, O.V. Kazanskiy
Impulse signal, a biological tissue, time domain, flatlayer dielectric, dispersion
Vestnik KhNU 806 Pages. 40-43

In this paper the interaction of the impulse signal with biological tissues on an example of the flatlayer dielectric that models consecutive layers a skin, fat, muscle tissue is investigated. In this model, it is taken into account dispersion of the dielectric permeability and losses in a medium. The calculation program is received in result. It accounts the space-time characteristics of the reflected and past signals for layers of the flatlayer dielectric with parameters of biological tissues. Influence of values of the dielectric permeability and angle of incidence on the characteristics of past and scattered signals also is considered.


Download >>


12.  CALCULATION AND MEASURING OF IMPEDANCE OF IMPATT-DIODE IN MILLIMETR WAVE
A.V. Arkhipov, V.T. Plaksiy, I.K. Kuzmichev, E.D. Prokhorov, A.V. Dydchenko, D.P. Chuechkov
millimeter wave range, Impedance, IMPATT diode, conductance, susceptance
Vestnik KhNU 806 Pages. 59-64

The calculated and experimental results of the impedance of the impact avalanche transit-time (IMPATT) diode for the 8 millimeter wavelength range have been presented. The dependences of the IMPATT diode impedance as a function of the normalized amplitude the fundamental current harmonic of the p-n junction and frequency have been calculated and measured. The apparatus and measuring method of the conductance and susceptance of the IMPATT diode has been developed


Download >>


13.  Identification and localization of radar impulses buried in noise
A. G. Tyzhnenko, Y. V. Ryeznik
radar, pulse, Identification, localization, low SNR
Vestnik KhNU 806 Pages. 70-74

Statistical method identification and localization of radar impulses buried in noise is addressed. To this end, the correlation coefficient between carrier samples measured in the extremal points and analogous set of points of received signal is proposed to implement. Such measurements for receiving signal need to be done at least by one tenth of the half period of the carrier. Because of very simple algorithm proposed, such measurements do not lead to heavy computational burden. To decrease identification and localization errors for given signal to noise ratio (SNR) one needs to increase the number of measurements points, and hence, the pulse width. To prevent this issue, one can increase the carrier frequency. In general, the method accuracy increases with the carrier frequency. The method proposed permits theoretically to identify with fidelity impulses buried in noise for SNR lower than -30 dB.


Download >>


14.  Target size and shape identification by multifrequency radar measurements E. V. Ryeznik, O. I.
Sukharevskiy, A. G. Tyzhnenko
Iceberg, shape and size identification
Vestnik KhNU 834 Pages. 31-36

A new method identification of targets shape and size is proposed. In this method, the values of RCS measured on the set of discrete frequencies are compared with the theoretical ones on the same set for canonical group of target configurations (patterns). 2D patterns implementation is considered instead of 3D patterns for the sake of scattering problems simplification. To this end, 2D RCS were transformed to 3D RCS under definite conditions. The method is implemented to the iceberg identification problem in model approach


Download >>


15.  Radiation of short pulses from the open end of waveguide
O.M. Dumin, O.O. Dumina, V.O. Katrich, Zheng Yu
transient field, modal basis method, evolutionary equations, Impulse field irradiation
Vestnik KhNU 834 Pages. 63-67

The problem of transient electromagnetic field radiation from the open end of waveguide is solved in time domain by the analytical and direct numeral methods. The problem of impulse signal propagation in regular waveguide is converted to the finding of transient wave propagation operator by modal basis method. The application of the operator for the obtaining of time form of signal both for the time change in positive and in the negative direction permits to seek an arbitrary time dependence of field amplitude in any point of waveguide taking into account distortions due to wave dispersion. The correction of diffraction distortions of time form of wave and forming the short probe impulse on the waveguide aperture by the excitation of waveguide in the given cross-section by field with the previously calculated time dependence are considered . Numerical simulation of short impulse irradiation of layered medium with losses is carried out


Download >>


16.  Features of radiation defect formation in kdp crystals under different kinds of irradiation
A.N. Levchenko
KDP single crystal, UV, Ionizing irradiation, radiation centers, ESR
Vestnik KhNU 834 Pages. 95-99

Formation processes of different types of radiation paramagnetic centers in potassium dihydrogen phosphate (KDP) single crystals under ultraviolet (UV), gamma-, electron, neutron and proton kinds of irradiation have been investigated with the help of electron spin resonance (ESR) method. The dose dependencies of the relative concentration of the impurity electron centers containing arsenic ions and hole-like centers with the hole localized on the p-orbit of oxygen ion have been measured. The comparison of the effects of the different kinds of irradiation on the radiation paramagnetic defect formation processes has been carried out


Download >>


17.  Pulse water insonification for laboratory research of electromagnetic wave propagation and dispersion in randomly inhomogeneous media in order to meet the conditions close to working ones
V.B. Yuferov, A.N. Ponomarev, E.V. Mufel, A.N. Ozerov, I.V. Buravilov, V.N. Ishenko
electromagnetic wave propagation, Inhomogeneous medium, air bubbles in liquid, acoustic pulse pneumatic radiator
Vestnik KhNU 834 Pages. 114-119

The efficiency of pulse water insonification by pneumatic radiator is shown. Such radiator enables the formation above the water surface of hydrometcors and aerosols with a desired concentration. It is necessary for laboratory research of fluctuation phenomena of the electromagnetic wave propagation in randomly inhomogeneous media. The use of pneumatic radiator makes possible lo remove salt from the solution. This enables a certain degree of control over liquid permittivity


Download >>


18.  Global Sensitivity analysis of the dipole matrix element according to variation of parameters of the indium surface segregation in ingan/gan quantum well
M.V. Klymenko
Indium surface segregation, semiconductor nitrides, piezoelectric polarization, dipole matrix element, global sensitivity analysis
Vestnik KhNU 853 Pages. 8-14

In this paper, influence of the indium surface segregation on dipole matrix element for InGaN/GaN heterostructure is under investigation. The global sensitivity analysis has been applied for quantitative estimation of the indium surface segregation effect at each interface of the quantum well. Together with the indium surface segregation, the piezoelectric effects are considered. It has been shown that joint action of the piezoelectric fields and the indium surface segregation leads to changes in the selection rules for optical transitions. Results give the method to apply the optical spectroscopy for observation of the indium surface segregation


Download >>


19.  Oscillation efficiency of TED diodes on the basis of nitrides
E. D. Prokhorov, O. V. Botsula, A. N. Zabazhan
AlN, GaN, InN-diodes, drift speed, oscillation efficiency
Vestnik KhNU 853 Pages. 15-21

Oscillation efficiency of intervalley transfer electrons diodes on the basis of nitrides (InN, GaN, AlN) is considered. Electric fields at peak oscillation efficiency are determined. The results have been compared to results for GaAs. The account of floatable potential in connections InGaN improves their power characteristics in comparison with power characteristics of these connections without taking into account floatable potential, maximal efficiency In0.8 Ga 0.2N and In0.5Ga0.5N diodes to compare to InN diodes on 30 % is higher (22 % to compare to 16,43 %) but at more high tensions of an electric field. The maximal oscillation efficiency is observed at higher electric fields than GaAs ( from 250 V/sm for InN to 1000 kV/sm for AlN)



20.  Algorithms of the processing signal from the trellised receiver for measuring of the laser radiation characteristics
Kokodiy N.G., Pak A.O.
the laser, optical radiation, Intensity, bolometer, direct task, reverse task
Vestnik KhNU 853 Pages. 37-44

In this paper has been considered the development of the device for the measurement of the intensity distribution in the beam of optical radiation. The algorithm of processing of a signal from the receiver of radiation is studied. The method of measurement of the intensity distribution of optical radiation by the bolometric grid is offered. The developed algorithms for processing a signal from the measuring converter and programs realizing them are checked up experimentally, their serviceability is confirmed. The comparative characteristic of algorithms based on the transformation of Fourier and transformation of Radon has shown an opportunity of their use in practice


Download >>


21.  Single cone with longitudinal slots excitation by an impulse point source
A.V. Artyukh, y.A. Doroshenko, Y.D. Shimuk
Impulse source, cone, longitudinal slots, analytical solution, numerical solution
Vestnik KhNU 853 Pages. 51-56

In this work the excitation of a semi-infinite perfectly conducting cone with periodic longitudinal slots by an impulse radial source problem is investigated. The solution of the well-posed initial-boundary problem is found using an analytically numerical method based upon Green function and Meler-Fock integral transforms applying. It is shown that the original electrodynamic problem is equivalent to the one of the Fredholm linear algebraic equations system of the second kind solving. Analytical view of the solution is derived and the graphs illustrating the field dependence on the aperture angle and angle slot width are presented


Download >>


22.  Asymptotic method of the solution of diffraction problem on the convex impedance cylinder, excited by the string of the electric current
V.I. Vyunnik, A.A, Zvyagintsev
diffraction, asymptotic method, Interpolation, convex impedance cilinder
Vestnik KhNU 853 Pages. 64-70

In the work considered the problem of diffraction electromagnetic waves on the convex impedance cylinder exited by string of the electric current, located near to its surface. The method asymptotic theories of the diffraction, offered by Fok is used. Are received asymptotic interpolation formulas for calculation radar cross section of the system string the current - cylinder, for a case of circular and elliptic impedance cylinders. The received formulas are suitable for calculations both in shadow and in lighted areas. It is shown, that these formulas can be distributed on a case of the any convex impedance cylinder with variable curvature


Download >>


23.  Paramagnetic properties of ASO2" free radical in irradiated KDP single crystals
A.N. Levchenko
KDP single crystal, Ionizing irradiation, free radicals, EPR, spin Hamiltonian
Vestnik KhNU 853 Pages. 84-87

The electron paramagnetic resonance (EPR) spectra of AsO22- free radical in potassium dihydrogen phosphate (KDP) single crystals irradiated with gamma rays and electrons have been investigated. The angular dependences of the spectra have been measured. The number of magnetically inequivalent sites for the AsO22- in the crystal lattice of KDP has been determined. The principal values of g-factor and hyperfine structure tensor have been calculated. It is found that the radical exhibits orthorhombic symmetry. The lagest component of hyperfine tensor is in the ab crystal plane. The molecular planes of the free radicals and the ab crystal plane are mutually perpenducular. The superhyperfine structure of the spectra indicates an existence of two protons near the paramagnetic center


Download >>


24.  Random inhomogeneous liquid medium as a continuous laser of low-intensity modulator for excitating sound in the medium
B. G. Yemets
laser, random inhomogeneous liquid medium, Interference, temperature field, optical acoustical phenomenon, sound, excitation, modulation
Vestnik KhNU 853 Pages. 95-100

When a medium is irradiated by laser pulses, sound waves are excited in this medium, i.e., the well-known optical acoustical phenomenon occurs. To excite sound oscillations, the specific laser beam modulator is shown to be unnecessary. The role of the modulator can play the liquid itself, which is a random inhomogeneous medium. The real liquid contains suspended solids and gas bubbles of small dimensions (dust particles and the like) that move irregularly in space (fluctuations). As a result, the electromagnetic wave interference taking place in the liquid undergoes random changes. Consequently, the temperature field changes, and hence variations in the local pressure occurs (thermo-optical mechanism for exciting sound). The excitation of sound due to the laser irradiation of low intensity is observed in an increase in the gas bubbles dimensions in the liquid


Download >>


25.  Analysis of impulse fields reflected from layered medium with losses using artificial neural network
Shyrokorad D. V., Dumin O.M., Dumina O.O., Katrich V.O.
time domain, artificial neural network, Impulse fields, layered medium
Vestnik KhNU 883 Pages. 35-40

The problem of determination of thickness a layer of layered medium by impulse irradiation is solved. The impulse fields reflected from the layered medium with electrical characteristics close to the characteristics of human skin are analyzed by artificia


Download >>


26.  FREQUENCY MULTIPLICATION AT IMPUCT IONIZATION IN TRASFER ELECTRON DIODES ON BASIS AlN, InN
E. D. Prokhorov, O.V. Botsula, I. A. Grishchenko
AlN, GaN, InN diodes, frequency transformation factor , drift velocity, harmonics.
Vestnik KhNU 883 Pages. 30-34

Multiplication of frequency at impact ionization in intervalley transfer electron diodes on basis InN, AlN is considered. The current voltage characteristics of intervalley transfer electron diodes have negative conductivity region and strong increasing


Download >>


27.  Dielectric permittivity profile reconstruction by frequency probing problem for a plane-layered media with regard to dispersion
Batrakov D.O., Simachov O.A.
plane layered media, dispersion, Inverse problem, dielectric permittivity
Vestnik KhNU 883 Pages. 45-49

In the present paper the problem of dielectric permittivity profile reconstruction with regard to dispersion is discussed. The nature of dispersion function is assumed to be known and unknown functions are real and imaginary parts of dielectric permittivi


Download >>


28.  Signal scattering on the meteor trail
Kharchenko H.V.
signal scattering, meteor trail, diffraction oscillations, electron density, plasma collective interaction, Impulse response.
Vestnik KhNU 966 Pages. 90-96

A generalized model of the radiosignal scattering on the meteor trail is proposed. The model allows to take into account the process of formation and development of the meteor trail, and to calculate the scattered signal power change without sharing the meteor trails on underdense and overdense. As input parameters of the model used the physical parameters of the meteoroid - the mass and velocity, which determine the ionization of the plasma formation, as well as the location and orientation of the meteor trail. In the derivation of the analytical relations taken into account the presence of the plasma sheath surrounding the 'metal cylinder' and the collective interactions in the plasma. In the paper shown that the results of calculations are in good agreement with observations.


Download >>


29.  

AlN, GaN, InN diodes, frequency transformation factor , drift velocity, harmonics.
Vestnik KhNU 883 Pages. 30-34

Multiplication of frequency at impact ionization in intervalley transfer electron diodes on basis InN, AlN is considered. The current voltage characteristics of intervalley transfer electron diodes have negative conductivity region and strong increasing current regions due to impact ionization that is nonlinearity and lead to transparent frequency. If impact ionization takes place, frequency transformation factor increases and reaches, for example, 40 % for second harmonic have being showed. The frequency transformation factor increases for second and third harmonic if first harmonic voltage amplitude is several threshold voltage if compare with frequency transformation factor for all nitride compounds.


Download >>


30.  

time domain, artificial neural network, Impulse fields, layered medium
Vestnik KhNU 883 Pages. 35-40

The problem of determination of thickness a layer of layered medium by impulse irradiation is solved. The impulse fields reflected from the layered medium with electrical characteristics close to the characteristics of human skin are analyzed by artificial neural network in time domain directly. The normal incidence of plane wave with Gaussian time form is considered. The reflected electromagnetic field is calculated by FDTD method. Initial data for the neural network analysis are the values of amplitude of electrical component of reflected field. As an example, the network is trained to determine the thickness of one of the layers of the medium. The stability of the determination in presence of interferences, experimental errors and instabilities of medium parameters is investigated.


Download >>


31.  

layered media, dispersion, Inverse problem, dielectric permittivity.
Vestnik KhNU 883 Pages. 45-49

In the present paper the problem of dielectric permittivity profile reconstruction with regard to dispersion is discussed. The nature of the dispersion function is assumed to be known and unknown functions are real and imaginary parts of dielectric permittivity. Frequency is used as an informative parameter. It is assumed that the layered medium is laying on a substrate with known dielectric permittivity and permeability. The iterative method reducing the problem of reconstruction to the functional minimization problem is used. Within the scope of this method the inverse problem for of dielectric permittivity profile with a conducting medium dispersion is solved. The algorithm and numerical results are given.


Download >>


32.  Impact of random variations of air hole diameters and random variations of the centers position of air holes on operation parameters of a solid core microstructured optical fiber
A.I. Filipenko, A.N. Donskov
finite-element method, Gaussian distribution, Inclusions diameter, total mode field power, angular positioning, microstructured optical fiber.
Vestnik KhNU 983 Pages. 29-32

We investigated the impact of random variations of air hole diameter and random variations of the centers position of air holes on operation parameters in the case of solid core microstructured optical fiber with a ring of air holes. The found results show that at any of considered defect types mode field will have two pronounced maximums. At practical use an investigated type of the MOF special angular positioning end faces of fibers is necessary. We also have shown that random variations of inclusions diameter can increase total mode field power. In our research we used finite-element method.


Download >>


33.  

thermal nonlinearity, optical beam, total reflection, Induced inhomogeneity, self-defocusing.
Vestnik KhNU 983 Pages. 33-37

The interaction of optical beams in media characterized by a refractive index depending on temperature is examined. The optical pump beam is partially absorbed by the medium induces a region with an inhomogeneous refractive index. As a result complete reflection, refraction or diffraction of the signal beam on the induced optical inhomogeneity may be observed. Experimental results on the research of this phenomenon are presented. Waveguide propagation of light in the region formed by two narrow pump beams is realized.


Download >>


34.  

optical element of the cylindrical form, light scattering, Monte-Carlo method, Indicatrix of scattering, Index of refraction
Vestnik KhNU 983 Pages. 67-71

Modeling of characteristics of optical spectral-selective elements of the cylindrical form with the increased value of the refraction index, using effect of light scattering is organized. The parameters of the optical element materials, forming its spectral-selective characteristic are determined. As have shown results of researches, application of cylindrical optical element for spectral angular selection is possible in limited range of values of the index of refraction. At increase in value of refraction index before determined level the optical element starts to function in a mode of quasi uniform light scattering.


Download >>


35.  

grid, bolometer, Intensity distribution, polarization, energy center, beam diameter, generalized cross-sectional square of the beam.
Vestnik KhNU 983 Pages. 72-76

In this paper the grid receiver for measuring laser radiation characteristics has been considered. The receiver contains four grids located perpendicular to the direction of propagation. Wire elements are located at angles 0 , 45?, 90? and 135? to the vertical. One grid contains 8 nickel bolometers with diameter 40 microns, bolometers are located on 7.2 mm from each other. The diameter of the window 60 mm. Intensity distribution in the space has been measured, therefore, the position of the energy center, the diameter, the generalized cross-sectional square of the radiation beam have been determined. The Radon transformation has been used as the mathematical basis of signal processing algorithms. Also the polarization direction and intensity distribution of polarized radiation have been measured by a numerical experiment.


Download >>


36.  

nitrides, Intervalley electron transfer, Monte Carlo method, homogeneous field mode.
Vestnik KhNU 927 Pages. 7-10

frequency properties of intervalley electrons transfer (IET) are considered in double nitride compound ALN. A frequency properties of AlN is determined by Monte Carlo method taking into account of all actual scattering mechanisms of electrons in the wide frequencies range to be corresponded to realization of limited space charge accumulation mode (LSA). The results of calculation of static characteristics and oscillation efficiency are presented. A frequency limits of oscillation efficiency of considered compound are defined. A region corresponding to neglecting of charge careers distribution inertia have been determined.


Download >>


37.  

plane dielectric waveguide, Inverted dielectric waveguide, Fourier transformation, Fredholm integral equation, dispersion equation.
Vestnik KhNU 927 Pages. 78-84

The eigenvawes problem of inverted dielectric waveguide is considered. The cross-section of waveguide is divided into partial domains in such way that the field in each domain is represented as a superposition of eigenwaves of a plane dielectric waveguide. Using the equality conditions of tangential components of electric and magnetic fields at the interface of domains two Fredholm integral equations of the second kind relatively waves amplitudes are obtained. The symmetric and asymmetric waves are considered. The dependencies of the propagation constant versus wave number and field distribution in the waveguide are presented.


Download >>


38.  

laser, optical radiation, Intensity, distribution, receiver, direct problem, Inverse problem.
Vestnik KhNU 927 Pages. 31-35

In this paper has been considered the method of the measurement of the intensity distribution in the beam of optical radiation and the algorithm of processing of a signal from the receiver. The method is using the knife attenuator of the special shape. The power of the reflected radiation on knife was measured by using detector of photoelectric. The algorithm and program for handling of the signal from receiver are developed. The influence of errors in the measurement signal from the receiver on the results of calculations has been researched. The experiment has confirmed the serviceability of the method and the possible of their use in practice.


Download >>

founded: 38 result (s)
Development wip.com.ua - V.N. Karazin Kharkov National university