THE SIMULATION OF METAL-DIELECTRIC ANTENNA ON THE BASE OF COMBINED APPROACH
I. Y. Lvovich, A. P. Preobrazhenskiy, O. N. Choporov, E. Ruzhitsky
The structure of modern radio transmitting devices may include antennas formed of both metal and dielectric components-metal-dielectric antennas. They are compact enough and can be placed on various objects of equipment. The paper presents a simulation of a metal-dielectric antenna based on a combined approach. The scheme of antenna construction in different planes is given. The process of scattering of a plane electromagnetic wave on an antenna is considered. The combined algorithm including the method of the integral equation, parallel approach and genetic algorithm is developed. In this paper, the integral equation is used to determine the unknown surface electric currents on the antenna surface, it is solved on the basis of the method of moments. A parallel algorithm was used to speed up the calculations. The impedance matrix is represented as a block matrix. Each block has its own parallel stream. Taking into account the influence of a plane dielectric waveguide on the scattered field, a method associated with a generalized scattering matrix is used. To solve the problem of multi-alternative optimization associated with determining the linear dimensions of the antenna device at a given operating frequency of the antenna, a genetic algorithm is used. As a result, the dimensions of the designed antenna for the specified dimensions of its components are obtained.
Keywords: : antenna, integral equation, parallel approach, optimization, genetic algorithm.
THE SIMULATION OF RADIO WAVE SCATTERING ON THE STRUCTURES WITH ABSORBING LAYER
E. V. Aleshkina
This paper describes the problem of scattering of radio waves in a complex diffraction structure having a cut absorptive coating on part of its surface. The system of integral equations in the framework of it contact density potentials, green function and the initial frequency was formed. Once solved the system of equations with the application of the relevant basis functions based on the method of moments was calculated values of the effective area of scattering at given conditions of observation. Suggestions were made on how to form a subsystem of CAD, which will provide opportunities to conduct designing of equipment with the necessary values of the scattering characteristics. As input to this subsystem, you can apply the scattering structure, the sector of observation angles, the required value of the level for the characteristics of scattering of radio waves.
Keywords: scattering of radio waves, absorption, modeling, integral equation.
THE ALGORITHMS THAT FORM THE IMAGE ON THE BISTATIC SYNTHETIC APERTURE RADAR, WHICH ARE PARASITIC ON THE TELEVISION SIGNAL
In the paper the analysis of the algorithm of forming radar images. Reviewed approximate and exact solutions of integral equations using iterative and collocation method. Marked features of the method of Fredholm determinants. Also the algorithm of receiving radar data in the framework of adaptive filtering. Considered a Fredholm equation of the second kind and the algorithm for obtaining the radar information by a method of adaptive filtering are derived a convenient formula for calculating the signal reflected from the surface. Considered the Fourier transform and equality Parseval and ambiguity function of the bistatic synthetic aperture radar. Launched a sounding signal using a sequence of pulses with a certain repetition period. It was also found that it is possible to filter data by adaptive equalization of amplitude-frequency characteristics, in order to compensate for features of uncertainty of television signals.
Keywords: signal, radar with synthetic aperture, integral equation.
THE SOLUTION OF THE PROBLEM OF SCATTERING OF ELECTROMAGNETIC WAVES IN MAGNETO-DIELECTRIC OBJECT BASED ON THE ADAPTIVE METHOD
T. V. Glotova, T.V.Melnikova
This paper discusses how adaptive integral method for solving the problem of scattering of electromagnetic waves on the object, which consists of several magneto-dielectric materials can be used. The integral equation to be solved with the help of this approach helps to eliminate resonance phenomena in dielectrics, and to obtain very accurate results. The method of moments is applied in order to carry out the process of discretization of integral equations is given and the resulting matrix system which is solved based on the iterative approach. As a result, the memory requirements is reduced to store intermediate results and to speed up matrix-vector multiplications. Numerical results that illustrate the accuracy and efficiency of this method are given.
Keywords: scattering of radio waves, method of moments, integral equation, magneto-dielectric materials, algorithm.
THE MODIFICATION OF THE METHOD OF MOMENTS IN THE SCATTERING OF ELECTROMAGNETIC WAVES
T. V. Glotova, T.V.Melnikova
The features of the solution of the integral equations used in the solution of problems of scattering of electromagnetic waves are discussed. The main methods that used are noted. It is proposed to modify the usual method of moments, due to the choice of basis and test functions. Examples of test objects used for the calculations are given. It was found that the more complex the contour of the object, the worse the condition number of linear equations. That is, the scale of the investigated basis functions may not be large. It is shown that if the solution of the integral equation is almost a linear function, the size of the linear equations can be significantly reduced compared to the original.
Keywords: technical electrodynamics, the scattering of radio waves, method of moments, integral equation, numerical method.
THE PROBLEMS OF CONTROL LEVEL OF SCATTERED ELECTROMAGNETIC FIELD
The paper discusses the problem of scattering of electromagnetic waves on a hollow structures. The proposals are given to the management of scattered electromagnetic field due to selection of the size of the object.
Keywords: hollow structure, integral equation, scattering, electromagnetic wave.
ABOUT THE POSSIBILITY OF CLARIFYING THICK-WIRE APPROXIMATION FOR VIBRATOR ANTENNAS
O.N. Gorbenko, A.A.Rozhkova
The discussion about the possibility of clarifying thick-wire approximation for vibrator antennas on the basis of comparison with a strict three-dimensional solution is held. The main phases of the algorithm is pointed out.
Keywords: antenna, integral equation, radio waves.