Tag Archives: diffraction

THE TECHNIQUE OF CALCULATION THE PARAMETERS OF THE ELECTROMAGNETIC THE FIELDS SCATTERED BY THE BODY WITH COMPLEX FORM IN THE NEAR ZONE

UDC 621.396

J.Stefanovic, E.Ruzitsky

The paper is based on the methodology that uses the representation of an object of complex shape as a set of facets, we investigate the characteristics of scattered by this object in its near zone. It is shown how, using the calculated data to explore the effect of the spatial configuration of the field on the accuracy of measurement of angular coordinates of the object. The calculated dependence of the relative field amplitude of the object and the plate from the corner for the near zone to the far zone. The graphical analysis of the dependencies shows that in addition to monotonic attenuation length fields exist oscillating damped oscillations. It is believed that the antenna is moved around the object at random are averaged over all viewing angles characteristics of the scattered field. After calculating the parameters of the distribution law of a random variable from section to section, we can conclude about how changing the process in time. The analysis demonstrates that when we move from the far zone to the near, there is a shift of peak values of amplitudes and is an extension of the main lobe of the secondary radiation. The histograms of the distributions of amplitudes and phases of a complex object, after analysis it was found that the distribution of instantaneous values of the amplitudes of the scattered field by the object is described by Rayleigh. If we consider the distribution of the instantaneous phase of the scattered field, the shape of the histogram is close in form to the histogram of a uniform law. The analysis of the results allows to assert that the regularities of the distribution of values of amplitudes and phases of the scattered field related to the far and near zones will be the same.

Keywords: complex object, electromagnetic wave, near zone, scattering, diffraction.

Full text:
StefanovicRuzitsky_2_17_1.pdf

THE MODELING OF THE SCATTERING OF RADIO WAVES OF CELLULAR COMMUNICATION SYSTEMS ON THE ELEMENTS OF BUILDINGS

UDC 621.396

A.A. Alimbekov, E.A. Avdeenko, V.V. Shevelev

This paper considers the problem of scattering of electromagnetic waves in cellular communication systems, elements of buildings. As a basic method is proposed to use the radial approach. The main steps of the algorithm for the calculation of total attenuation of the signal caused by the diffraction at the corners of buildings. The loss caused by reflection of the radio signal from the earth, are calculated based on the Fresnel coefficients for a plane wave. Indicated input parameters for the calculation. A diagram of the module of calculation of fields scattered by buildings, which uses a block optimization. A classification of optimization techniques used in the optimization of communication systems. Methods associated with unconditional optimization are divided into: one-dimensional case multidimensional case. Optimization methods are divided into these: optimization under linear constraints, optimization under nonlinear constraints.

Keywords: diffraction, building, link, beam, electromagnetic wave scattering.

Full text:
AlimbekovAvdeenko_1_17_2.pdf

THE RESEARCH OF FEATURES OF DIFFRACTION PROCESSES IN THE HIGH FREQUENCY RANGE

UDC 621.396

V.G. Panarin, A.G.Yurochkin

This paper discusses the features of processes of diffraction of electromagnetic waves in the high frequency range as it is promising from the point of view of further development of communication systems. It is noted that with the increase in frequency is required to consider the objects surface on which the diffraction as rough. The numerical simulation is introduced the Fresnel’s coefficient of roughness. This description of the reflection coefficients taking into account the surface roughness. Given the calculated reflection coefficients for different polarizations of the incident electromagnetic wave depending on frequency. The dependence of the reflection coefficient depending on angle of incidence for a given frequency of the incident electromagnetic wave.

Keywords: diffraction, electromagnetic waves, reflection coefficient, Fresnel’s coefficient.

Full text:
PanarinYurochkin_3_16_1.pdf

THE ANALYSIS OF ELECTROMAGNETIC WAVE PROPAGATION INSIDE THE BUILDING WITHIN THE RADIAL APPROACH

UDC 621.396

A. P. Preobrazhensky

In this paper the analysis of the characteristics of radiation methods for the analysis of electromagnetic wave propagation – the method of geometrical optics, physical optics, physical theory of diffraction are considered. In order to determine the amplitude of the field in each point of space is required to determine all the rays that pass through this point. The considered model of distribution of the main beam in the room for two cases – floor reflections and the reflection from the object, located a certain height above the floor. Built according to the horizontal distance to the point of reflection of the beam on the incidence angle, the height of the receiver from the angle of reflection, the height of the receiver for various values of height of the reflecting object.

Keywords: simulation, communication, diffraction, wave propagation in indoor radiation methods.

Full text:
Preobrazhensky_2_16_2.pdf

THE SIMULATION OF SCATTERING CHARACTERISTICS OF OBJECTS HAVING EDGES

UDC 621.396

A. P. Preobrazhensky

In the paper the problems of scattering of radio waves on the objects, which include edge are considered. First, the analysis of the simplest edges, which is a wedge-shaped structure having a certain angle of solution is given. For the general case the edge of such structures may be truncated. The calculations of the scattering parameters was based on the method of integral equations in the framework of the Kirchhoff approximation. The examples of calculations of scattering characteristics are given, and built the radio image. Further the models of hollow structures is considered. The edges of these hollow structures can be defined by different edges. The calculations of the scattering parameters was based on the method of integral equations. The examples of calculations of scattering characteristics of hollow structures, and built the radio image of the edge part of the hollow structure.

Keywords: simulation, communication, diffraction, wave propagation, design, edge, hollow structure.

Full text:
Preobrazhensky_2_16_1.pdf

THE POSSIBILITY OF USING ITERATIVE METHOD FOR THE CALCULATIONS OF SCATTERING CHARACTERISTICS OF COMBINED OBJECTS

UDC 621.396

A. G. Yurochkin, A.V.Danilova, I.A.Gusarova

This paper considers the scattering of radio waves on the combined object consisting of several components. One of the possible ways, which is analyzed by the application of the method of integral equations. But with a large size of circuits and an increase in the number of components the time required for calculations increases significantly. In this regard, the iterative method is considered, which takes into account only the currents that are related directly to the reflection between components, which leads to a reduction in the size of the matrix of linear equations and an overall reduction in the computation time. Given an example, when as a combined object is a combination of two-dimensional elliptic cylinders. Characteristic size at which the iterative method works well.

Keywords: communication, diffraction, wave propagation, method of integral equations, iteration, cylinder.

Full text:
YurochkinDanilovaGusarova_2_16_2.pdf

THE ANALYSIS OF APPROXIMATE MODELS FOR ESTIMATING THE AVERAGE CHARACTERISTICS OF THE SCATTERING DIFFRACTIVE STRUCTURE

UDC 621.396

A. G. Yurochkin, A.V.Danilova, I.A.Gusarova

This paper analyses the possibilities of how to apply the approximate model in order to assess the average characteristics of the scattering object. The exact approach is based on the method of integral equations, and an approximate model based on the combination of the method of edge waves and the physical optics approximation. The object is represented in the form of separate components. It is shown how the defined sector angles, given the framework of specific errors. Based on how aggregated information on the elements of an object given suggestions on how to build a subsystem of CAD in order to design the average characteristics of the objects. As a test data for the subsystem are selected dimensions of the elements and sector angles, the required levels for the average characteristics of the scattering.

Keywords: communication, diffraction, wave propagation, design, CAD, diffraction structure.

Full text:
YurochkinDanilovaGusarova_2_16_1.pdf

THE CHARACTERISTICS OF TWO-DIMENSIONAL PERIODIC COMBS WITH DIELECTRIC WAVEGUIDE

UDC 621.396

A. A. Maximova

The paper discusses the issues of diffraction of electromagnetic waves on reflective comb with double periodicity is covered by a dielectric layer. The algorithm, which is considered, based on the method of integral equations for the problem of determining the currents on the surface of the comb. The obtained result can be generalized to two-dimensional comb. According to the found current density distribution on the surface of the comb element can be determined of the scattered electromagnetic field.

Keywords: scattering of radio waves, diffraction, two-dimensional-periodic comb filters, dielectric waveguide.

Full text:
Maksimova_1_16_1.pdf

MODELLING OF DISPERSION OF ELECTROMAGNETIC WAVES IN AN INHOMOGENEOUS MAGNETO-DIELECTRIC BODIES

UDC 621.396

A.A. Maximova

In this paper, the analysis in the time domain based integral equation approach. The approach is considered for describing of transient processes in composite metal-dielectric bodies is given. Numerical examples are given to demonstrate the stability and precision of the proposed method. As the object of analysis is a metal cylinder.

Keywords: modeling, scattering on magneto-dielectric body, diffraction.

Full text:
Maksimova_4_15_2.pdf

THE APPLICATION OF SIMPLIFIED APPROACHES IN THE ANALYSIS OF THE ELECTRODYNAMIC CHARACTERISTICS OF OBJECTS

UDC 621.396

E.M.Buldigin

The paper considers possibilities of use of approximate methods in the evaluation of characteristics of complex objects. It was noted that when using research Institute of these approaches is significantly reduced the time required.

Keywords: diffraction, scattering, the algorithm, object.

Full text:
Buldigin_2_14_1.pdf