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  • 1.
    Angermann, L.
    et al.
    Institut für MathematikTechnische Universität Clausthal, Clausthal-Zellerfeld, Germany.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Smirnov, Y. G.
    Department of Mathematics and Supercomputing, Penza State University, Penza, Russia.
    Yatsyk, V. V.
    O.Ya. Usikov Institute for Radiophysics and Electronics, National Academy of Sciences of Ukraine, Kharkiv, Ukraine.
    A nonlinear multiparameter EV problem2018In: Progress In Electromagnetics Research Symposium: PIERS 2017, PIERS 2017: Nonlinear and Inverse Problems in Electromagnetics / [ed] Beilina L., Smirnov Y., Springer New York LLC , 2018, p. 55-70Conference paper (Refereed)
    Abstract [en]

    We investigate a generalization of one-parameter eigenvalue problems arising in the theory of wave propagation in waveguides filled with nonlinear media to more general nonlinear multi-parameter eigenvalue problems for a nonlinear operator. Using an integral equation approach, we derive functional dispersion equations (DEs) whose roots yield the desired eigenvalues. The existence of the roots of DEs is proved and their distribution is described.

  • 2.
    Angermann, Lutz
    et al.
    Clausthal University of Technology, Clausthal, Germany..
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Yatsyk, Vasyl
    O. Ya, Usikov Institute for Radiophysics and Electronics of the National Academy of Sciences of Ukraine, Kharkiv, Ukraine.
    Mathematical models for scattering and generation of plane wave packets on layered cubically polarisable structures2013In: Far East Journal of Applied Mathematics, ISSN 0972-0960, Vol. 81, no 1-2, p. 1-31Article in journal (Refereed)
    Abstract [en]

    The paper deals with different formulations of mathematical models for the analysis of processes of resonance scattering and generation of plane wave packets on isotropic, nonmagnetic, linearly polarised media with a nonlinear, layered dielectric structure of cubic polarisability. For each formulation, sufficient conditions for the existence and, partially, uniqueness of the corresponding solution are derived.

  • 3.
    Angermann, Lutz
    et al.
    Technische Universität Clausthal, Institut für Mathematik, Clausthal-Zellerfeld, Germany .
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Yatsyk, Vasyl V.
    O.Ya. Usikov Institute for Radiophysics and Electronics of the National Academy of Sciences of Ukraine, Kharkiv, Ukraine .
    Eigenmodes of linearised problems of scattering and generation of oscillations on cubically polarisable layers2015In: Inverse Problems and Applications / [ed] Larisa Beilina, Springer-Verlag New York, 2015, Vol. 120, p. 67-80Conference paper (Refereed)
    Abstract [en]

    In the frequency domain, the resonant properties of nonlinear structures are determined by the proximity of the scattering/generation frequencies of the nonlinear structures to the complex eigenfrequencies of the corresponding homogeneous linear spectral problems with the induced nonlinear permeability of the medium. Here the case of cubically polarisable, canalising, and decanalising layers is considered.

  • 4.
    Beilina, Larisa
    et al.
    Department of Mathematical Sciences, Chalmers University of Technology, Gothenburg University, Gothenburg, Sweden.
    Bondestam Malmberg, John
    Department of Mathematical Sciences, Chalmers University of Technology, Gothenburg University, Gothenburg, Sweden.
    Cristofol, Michel
    Institut de Mathematiques de Marseille, CNRS, UMR 7373, Ecole Centrale, Aix-Marseille University, Marseille, France.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Preface for the session "recent Progress in Electromagnetic Field Theory and New Trends in Inverse Problems"2017In: AIP Conference Proceedings, ISSN 0094-243X, E-ISSN 1551-7616, Vol. 1863, article id 370001Article in journal (Refereed)
  • 5.
    Cappello, Barbara
    et al.
    Politecnico di Torino, Torino, Italy.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Matekovits, Ladislau
    Politecnico di Torino, Torino, Italy.
    Analysis of the surface impedance of a sinusoidally modulated metasurface2019In: 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA), IEEE, 2019, p. 0075-0077Conference paper (Refereed)
    Abstract [en]

    Metasurfaces have been extensively exploited in recent years for mantle cloaking applications. In this type of problems it is of fundamental importance to determine the connection between the metasurface geometrical parameters and the realised value of surface impedance, in order to properly design the metasurface. In this paper the surface impedance of a non homogeneous metasurface, based on a sinusoidally modulated metallic pattern is analysed.

  • 6.
    Derevyanchuk, E. D.
    et al.
    Penza State University, Penza, Russia.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Derevyanchuk, Natalia V.
    Penza State University, Penza, Russia.
    Reconstruction of Electromagnetic Parameters of a Thin Anisotropic Dielectric Slab2018In: 2018 Progress in Electromagnetics Research Symposium (PIERS-Toyama), 2018, p. 1968-1972Conference paper (Refereed)
    Abstract [en]

    Reconstruction of electromagnetic parameters of artificial materials is an urgent problem [1], [2]. In practice, as a rule, these parameters cannot be directly measured. Therefore, methods of mathematical modeling must be applied. Conventional waveguide measurement equipment employs network analyzers and dielectric samples having the simplest shape of a parallelepiped adjusted to the walls of a standard rectangular waveguide. Such setups open the way to use well-developed analytical-numerical techniques [3], [4] of determining permittivity and other parameters of the inclusion using accurate closed-form solutions and asymptotic approximations. This work is a continuation of the series of papers [3], [4] devoted to the analysis of inverse problems of finding permittivity and permeability of layered materials. We apply a specially developed mathematical and numerical technique that combines analytical and numerical approaches providing the results with guaranteed accuracy. Particularly, we develop the methods [3] of determining permittivity and permeability tensors of anisotropic materials in a rectangular waveguide.

  • 7.
    Derovyanchuk, E. D.
    et al.
    Penza State University, Penza, Russia.
    Smirnov, Y. G.
    Penza State University, Penza, Russia.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Reconstructing Permittivity and Permeability of Multi-Sectional Anisotropic Diaphragms2018In: 2018 Progress in Electromagnetics Research Symposium (PIERS-Toyama), 2018, p. 1963-1967Conference paper (Refereed)
    Abstract [en]

    A great variety of new and artificial materials have been created during the last decades, such as metamaterials, various composites and many others. To analyze and determine the characteristics of such materials advanced mathematical methods are applied. This work is devoted to the developing the technique for reconstruction of electromagnetic parameters of multi-sectional anisotropic diaphragms in a waveguide of rectangular cross section. To solve this inverse problem we make use of the method of rotation applied for anisotropic materials and reconstruct the quantities to be determined, including the diaphragm positions, from the values of the transmission coefficient measured at different frequencies. The efficiency and accuracy of computations are validated in the course of analytical-numerical solution to the inverse problem. The developed techniques and obtained results can be implemented in practical measurements when anisotropic materials and media with unknown properties are investigated with the aid of commonly used waveguide devices and analyzers.

  • 8.
    Ivanchenko, I.
    et al.
    O. Ya. Usikov Institute for Radiophysics and Electronics of the NAS of Ukraine, Kharkiv, Ukraine.
    Khruslov, M.
    O. Ya. Usikov Institute for Radiophysics and Electronics of the NAS of Ukraine, Kharkiv, Ukraine.
    Popenko, N.
    O. Ya. Usikov Institute for Radiophysics and Electronics of the NAS of Ukraine, Kharkiv, Ukraine.
    Sheina, E.
    Lomonosov Moscow State University, Russia.
    Smirnov, A.
    Lomonosov Moscow State University, Russia.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Reconstructing complex permittivity of local inhomogeneites in a radio-transparent dielectric matrix located in a waveguide2016In: 2016 22nd International Conference on Applied Electromagnetics and Communications (ICECOM), 2016Conference paper (Refereed)
    Abstract [en]

    The results are presented of the numerical solution to the forward problem of the electromagnetic wave scattering by inhomogeneous dielectric bodies in a waveguide and inverse problem of determining parameters of dielectric inclusions from the values of the transmission coefficient of the scattered electromagnetic wave. A comparison with the results of mesurements and analysis of the achieved threshold computational accuracy levels enable one to estimate and validate the simulation results and formulate the ways of improving the model and codes.

  • 9.
    Ivanchenko, I.
    et al.
    O. Ya. Usikov Institute for Radiophysics and Electronics of the NAS of Ukraine, Kharkiv, Ukraine.
    Khruslov, M.
    O. Ya. Usikov Institute for Radiophysics and Electronics of the NAS of Ukraine, Kharkiv, Ukraine.
    Popenko, N.
    O. Ya. Usikov Institute for Radiophysics and Electronics of the NAS of Ukraine, Kharkiv, Ukraine.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Rönnow, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Electronics.
    Combined system of the microstrip antennas with different frequencies2016In: 2016 22nd International Conference on Applied Electromagnetics and Communications (ICECOM), 2016Conference paper (Refereed)
    Abstract [en]

    The combined system with microstrip antennas (f1=1.85GHz; f2=3.7GHz, f3=1.75GHz, f4= 3.5GHz) is presented. The measurements of the prototype characteristics have shown that elevation angle of peak directivity of the antennas is oriented to zenith. Simulated S11 at stated frequencies with the following minimum values of S11 = -34dB, f=1.85GHz; S11=-21dB, f=3.7GHz; S11 = -22dB, f=1.75GHz; S11=-19dB, f=3.5GHz are observed.

  • 10.
    Ivanchenko, Igor
    et al.
    O.Ya. Usikov Institute for Radiophysics and Electronics, National Academy of Sciences of Ukraine, Kharkiv, Ukraine.
    Khruslov, Maksym
    O.Ya. Usikov Institute for Radiophysics and Electronics, National Academy of Sciences of Ukraine, Kharkiv, Ukraine.
    Popenko, Nina
    O.Ya. Usikov Institute for Radiophysics and Electronics, National Academy of Sciences of Ukraine, Kharkiv, Ukraine.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Tripathy, Malay Ranjan
    Amity University, Delhi, India.
    Derevyanchuk, Ekaterina
    Penza State University, Penza, Russian Federation.
    Determination of effective permittivity of metamaterial antenna cells2016In: 2016 10th European Conference on Antennas and Propagation: EuCAP 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, article id 7481369Conference paper (Refereed)
    Abstract [en]

    A numerical-analytical method of reconstructing complex frequency-dependent permittivities is proposed. Measurements of the transmission coefficient for three typical metamaterial antenna units are performed and the frequency-dependent effective complex permittivity of the units is reconstructed in a wide frequency range.

  • 11.
    Khulbe, Manisha
    et al.
    Ambedkar Institute of Advanced Communication Technologies and Research (AIACTR), Delhi, India.
    Tripathy, Malay Ranjan
    Amity School of Engineerng and Technology, Amity University, Noida, India.
    Parthasarathy, Harish
    Netaji Subhash Institute of Technology (NSIT), N. Delhi, India.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Lagovsky, Boris
    Russian Technological University, MIREA, Moscow, Russia.
    Inverse Scattering and Imaging Using Second Order Optical Nonlinearities2019In: 2019 6th International Conference on Signal Processing and Integrated Networks, SPIN 2019, IEEE, 2019, p. 1086-1089Conference paper (Refereed)
    Abstract [en]

    In this paper a mathematical technique is developed to find the parameters of a medium in terms of its scattered electromagnetic fields. Optical nonlinearity plays an important role in finding the scattering parameters of a medium. Using perturbation theory and nonlinear inverse scattering techniques with first order, second order and third order optical nonlinearity we find scattered electromagnetic fields. Using error minimization techniques parameters are estimated in term of permittivity and permeability up to second order. © 2019 IEEE.

  • 12.
    Kimsis, Karlis
    et al.
    Riga Technical University.
    Semenjako, Janis
    Riga Technical University.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Mechanically tunable coupled resonator waveguide bandpass filter2019In: 2019 IEEE Microwave Theory and Techniques in Wireless Communications (MTTW), 2019, Vol. 1, p. 52-56Conference paper (Refereed)
    Abstract [en]

    This paper proposes a novel mechanically tunable waveguide filter design, based on a coupled resonator topology. The resonator geometry consists of a rectangular waveguide cavity and a dielectric cylinder. Unlike conventional cylindrical resonators which are made out of a single part, here the cylinders are cut in half. By changing the distance between these two parts, the resonating frequency of the resonator can be changed, which allows for a tunable filter design. A filter using the proposed geometry has a large tuning bandwidth as well as relatively constant passband frequencies. The performance of the proposed filter is demonstrated by evaluating the filter using 3D simulation software CST Studio Suite.

  • 13.
    Kushnin, R.
    et al.
    Riga Technical University, Latvia.
    Semenjako, J.
    Riga Technical University, Latvia.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Accelerated boundary integral method for solving the problem of scattering by multiple multilayered circular cylindrical posts in a rectangular waveguide2017In: 2017 Progress In Electromagnetics Research Symposium - Fall (PIERS - FALL), Electromagnetics Academy , 2017, p. 3263-3271Conference paper (Refereed)
    Abstract [en]

    An accelerated boundary integral method for the analysis of scattering of the dominant mode by multiple multi-layered full-height circular cylindrical posts in a rectangular waveguide is presented. After some transformations the surface integral equation is converted to a system of equations whose entries can be evaluated analytically yielding Schlömilch series. Slow convergence of these series is accelerated using the Ewald technique. The proposed method gives results that are comparable in terms of accuracy with other approaches, including those incorporated in solvers HFSS and CST Studio and outperforms them in terms of computation time, especially for posts with large electrical sizes. The efficiency of the proposed method is confirmed by the examples of H-plane cylinder bandpass filters design.

  • 14.
    Kushnin, R.
    et al.
    Riga Technical University, Latvia.
    Semenjako, J.
    Riga Technical University, Latvia.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Maximum-sensitivity method for minimizing uncertainty in the measurements of permittivity of a cylindrical dielectric sample in a rectangular waveguide2017In: 2017 Progress In Electromagnetics Research Symposium - Fall (PIERS - FALL), Electromagnetics Academy , 2017, p. 570-578Conference paper (Refereed)
    Abstract [en]

    A novel and efficient methodology is proposed for reducing measurement uncertainty associated with the dielectric constant of low-loss materials. The experimental setup consists of two H-plane cylindrical rods located in a rectangular waveguide. One of the rods has the unknown dielectric constant to be extracted, while the other dielectric rod whose dielectric constant is known in advance and serves as a tool for altering the shape of the dependence of the absolute value of the reflection coefficient on the dielectric constant in such a way that the resulting curve exhibits more rapid variations in the range of possible values of the dielectric constant of the post being characterized. The distance between the rods, radius of the optimizing rod, and position offset of the optimizing post serve as optimization parameters to be adjusted so that measurement uncertainty could be reduced which is confirmed by the results of numerical modeling. However, in the vicinity of the resonances, the method cannot be applied. © 2018 Electromagnetics Academy. All rights reserved.

  • 15.
    Kushnin, R.
    et al.
    Riga Technical University, Latvia.
    Semenjako, J.
    Riga Technical University, Latvia.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Viduzs, A.
    Riga Technical University, Latvia.
    Two-Slab High Sensitivity Technique for Measurement of Permittivity of a Dielectric Slab in a Rectangular Waveguide2018In: 2018 Progress in Electromagnetics Research Symposium (PIERS-Toyama), 2018, p. 176-183Conference paper (Refereed)
    Abstract [en]

    In the present paper an approach to reduce uncertainty in the measurement of the dielectric constant of a rectangular dielectric slab situated in a rectangular waveguide is discussed. The experimental model under consideration consists of two rectangular full height and full width slabs located in an otherwise empty section of a rectangular waveguide. The dielectric constant of one of these slabs is to be measured, while the dielectric constant of the other slab is known (measured with high accuracy in advance). The slab with known constitutive properties is introduced for the purpose of altering the shape of the curve representing the relationship between the absolute value of the reflection coefficient and the dielectric constant to be measured, since curves having larger steepness in the neighborhood of the actual value of the dielectric constant result in smaller values of uncertainty. Although it is possible to change the shape of the curve by varying sample parameters, an increase in steepness obtained this way is not always sufficient. Furthermore, it is not always possible or convenient to alter dimensions of the sample under test and/or frequency. The results of the present study show that this issue can be overcome by extending the experimental model, i.e., by introducing an auxiliary dielectric slab with known constitutive properties. Additionally, it is shown that under certain conditions it is always possible to increase the steepness of the curve in the range of values in which the value of the dielectric constant is expected to fall, by varying the thickness of the auxiliary slab and distance between the slabs. The efficiency of the proposed approach is confirmed by results of numerical modeling.

  • 16. Kuzmina, E. A.
    et al.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Complex Waves in Multi-Layered Metal-Dielectric Waveguides2018In: Proceedings of the 2018 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2018, p. 122-125, article id 8520457Conference paper (Refereed)
    Abstract [en]

    We consider normal waves in multi-layered dielectric rod and Goubau line that are basic types of open metal-dielectric waveguides. The dispersion equations are analyzed using the notion of generalized cylindrical polynomials and methods of calculating determinants of block-diagonal matrices. Sufficient conditions of the existence of symmetric waves are established.

  • 17.
    Kuzmina, E. A.
    et al.
    Institute of Information Technologies, Moscow Technological University (MIREA), 86 Vernadsky Avenue, Moscow, Russian Federation.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Complex waves in a dielectric rod and goubau line2017In: 2017 International Conference on Electromagnetics in Advanced Applications (ICEAA), Institute of Electrical and Electronics Engineers Inc. , 2017, p. 963-966, article id 8065417Conference paper (Refereed)
    Abstract [en]

    Existence of complex TM and TE waves in a dielectric waveguide of circular cross section and a Goubau line is proved by analyzing functional properties of the dispersion equations (DEs) using the theory of functions of several complex variables and validating the existence of complex roots of DE. The method proceeds from the analysis of general setting involving hybrid nonsymmetric azimuthally dependent real and complex waves.

  • 18. Kuzmina, E.
    et al.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Higher-order surface modes in the Goubau line2014In: Progress in Electromagnetics Research Symposium, Electromagnetics Academy , 2014, p. 2605-2609Conference paper (Refereed)
    Abstract [en]

    Existence of the higher-order surface waves of the Goubau line is proved and their structure is analyzed. An efficient computational approach is proposed based on numerical solution to initial-value problems obtained by the parameter differentiation. Several applications and further research directions are discussed.

  • 19.
    Kuzmina, Ekaterina
    et al.
    Moscow Technical University MIREA, Moscow, Russia.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Symmetric surface complex waves in Goubau Line2018In: Cogent Engineering, ISSN 2331-1916, Vol. 5, no 1, article id 1507083Article in journal (Refereed)
    Abstract [en]

    Existence of symmetric surface complex waves in a Goubau line—a perfectly conducting cylinder of circular cross-section covered by a concentric dielectric layer—is proved by constructing perturbation of the spectrum of symmetric real waves with respect to the imaginary part of the permittivity of the dielectric cover. Closed-form iteration procedures for calculating the roots of the dispersion equation (DE) in the complex domain supplied with efficient choice of initial approximation are developed. Numerical modeling is performed with the help of a parameter-differentiation method applied to the analytical and numerical solution of DEs.

  • 20.
    Kuzmina, Ekaterina
    et al.
    Moscow State Institute of Radio Engineering, Electronics and Automation, Technical University, Moscow, Russian Federation.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Waves in a lossy Goubau line2016In: 2016 10th European Conference on Antennas and Propagation: EuCAP 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, article id 7481368Conference paper (Refereed)
    Abstract [en]

    We consider a homogeneous Goubau line (GL) with a lossy cover. We analyze the dispersion equation for symmetric waves with respect to the problem parameters, find radially symmetric complex waves, and examine their behavior. We show that longitudinal wavenumbers of complex waves are regular perturbations of the propagation constants of eigenwaves of lossless GL, weakly depend om the imaginary part of permittivity of the cover, and that attenuation in GL is low at higher losses.

  • 21.
    Lagovsky, B. A.
    et al.
    Deptartment of Applied Mathematics, Moscow Technological University, Moscow, Russian Federation.
    Samokhin, A. B.
    Deptartment of Applied Mathematics, Moscow Technological University, Moscow, Russian Federation.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Creating Two-Dimensional Images of Objects with High Angular Resolution2018In: Proceedings of 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP), 2018, p. 114-115Conference paper (Refereed)
    Abstract [en]

    A new method of digital radar signal processing for remote sensing is proposed. The technique allows one to obtain two-dimensional images of objects with super resolution. The method is based on solving a convolution-type two- dimensional linear integral equation of the first kind by algebraic methods.

  • 22.
    Lagovsky, B. A.
    et al.
    Moscow Technological University, Moscow, Russia.
    Samokhin, A. B.
    Moscow Technological University, Moscow, Russia.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Increasing accuracy of angular measurements using UWB signals2017In: 2017 11th European Conference on Antennas and Propagation, EUCAP 2017, Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 1083-1086Conference paper (Refereed)
    Abstract [en]

    We show that dispersion characteristics of antenna patterns should be taken into account when developing systems using UWB signals. The accuracy of measurement of angular coordinates of objects using UWB pulses is increased by optimizing their shape based on known characteristics of the antenna system and at least partially known characteristics of the investigated signal source. Optimization algorithms allow to minimize the width of the directional pattern for a given level of the useful signal.

  • 23.
    Lagovsky, B. A.
    et al.
    Moscow State Institute of Radio Engineering and Automation, Technical University, Moscow, Russian Federation.
    Samokhin, A. B.
    Moscow State Institute of Radio Engineering and Automation, Technical University, Moscow, Russian Federation.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Pulse characteristics of antenna array radiating UWB signals2016In: 2016 10th European Conference on Antennas and Propagation: EuCAP 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, article id 7481624Conference paper (Refereed)
    Abstract [en]

    Dispersion properties of the mutual impedance of emitters significantly alter the shape and spectrum of ultra-wideband (UWB) signals which must be taken into account when forming the signal. In order to take into consideration mutual coupling of elements we propose to use pulse characteristics in the antenna performance analysis and calculations. This approach allows us to simplify calculations of UWB antenna systems and improve their accuracy.

  • 24.
    Lagovsky, B. A.
    et al.
    Russian Technological University (MIREA), Moscow, Russia.
    Samokhin, A. B.
    Russian Technological University (MIREA), Moscow, Russia.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Regression Methods of Obtaining Angular Superresolution2019In: 2019 URSI Asia-Pacific Radio Science Conference (AP-RASC), New Dehli: IEEE, 2019, article id 8738539Conference paper (Refereed)
    Abstract [en]

    New methods of signal processing based on nonlinear regression methods are presented. They allow us to restore images of individual objects of group targets with superresolution at signal-to-noise ratios that are significantly lower than those provided by the known methods.

  • 25.
    Lagovsky, B.
    et al.
    Moscow Technological University (MIREA), Moscow, Russian Federation.
    Samokhin, A.
    Moscow Technological University (MIREA), Moscow, Russian Federation.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Increasing effective angular resolution of measuring systems based on antenna arrays2016In: 2016 URSI International Symposium on Electromagnetic Theory (EMTS): Conference publications, IEEE conference proceedings, 2016, p. 432-434Conference paper (Refereed)
    Abstract [en]

    Resolution of goniometric systems on the basis of antenna arrays can be increased due to the secondary digital processing of the accepted signals. Necessary algorithms are created on the basis of solution to inverse problems.

  • 26. Lagovsky, Boris A.
    et al.
    Samokhin, Alexander B.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Superresolution based on the methods of extrapolation2015In: PIERS 2015 Prague: Progress in Electromagnetics Research Symposium : Proceedings, Cambridge, MA: The Electromagnetics Academy , 2015, p. 1548-1551Conference paper (Refereed)
    Abstract [en]

    A new method of signal processing by smart antennas is proposed and justified. It allows to improve the accuracy of angle measurement and to restore the image of the object with superresolution. The method is based on the extrapolation of the signals received by each element of the antenna array, outside the aperture. This allows introducing new virtual elements and thus synthesizing significantly larger antenna array. The method is tested in numerical experiments using a mathematical model and the maximum effective angular resolution is found for different cases and objects. Algorithms based on the method of digital aperture synthesis provide angular superresolution 3-7 times greater than that according to the Rayleigh criterion for a signal/noise ratio of 12-13 dB.

  • 27.
    Nakonechny, A. G.
    et al.
    Taras Shevchenko National University of Kyiv, Ukraine.
    Podlipenko, Y. K.
    Taras Shevchenko National University of Kyiv, Ukraine.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Aposteriori estimates in inverse problems for the Helmholtz equation2017In: 2017 Progress In Electromagnetics Research Symposium - Fall (PIERS - FALL), Electromagnetics Academy , 2017, p. 3526-3531Conference paper (Refereed)
    Abstract [en]

    We consider the problem of estimation of the right-hand sides of the Helmholtz equation that models electromagnetic and acoustic wave fields when that initial data is uncertain. In the case when measurement errors depend on solutions, we construct algorithms of computation of the optimal estimates which are compatible with the measurement data. It is shown that approximate a posteriori estimates of the right-hand sides are expressed via solutions of linear algebraic equations.

  • 28.
    Nakonechny, Alexander G.
    et al.
    Taras Shevchenko National University of Kyiv, Kyiv, Ukraine.
    Podlipenko, Yuri K.
    Taras Shevchenko National University of Kyiv, Kyiv, Ukraine.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Guaranteed a posteriori estimates of right-hand sides in transmission problems for Helmholtz equations2017In: 2017 XXXIIND GENERAL ASSEMBLY AND SCIENTIFIC SYMPOSIUM OF THE INTERNATIONAL UNION OF RADIO SCIENCE (URSI GASS), Institute of Electrical and Electronics Engineers (IEEE), 2017Conference paper (Refereed)
    Abstract [en]

    In this work we describe a method of obtaining guaranteed a posteriori estimates of unknown right-hand sides of the Helmholtz transmission problems from indirect measurements of a solution to this problem. The obtained results can be applied in various models of electromagnetics and acoustics that describe excitation of transparent bodies by sources of different kinds.

  • 29.
    Nakonechny, Alexander
    et al.
    T. Shevchenko Kyiv National University, Kyiv, Ukraine.
    Podlipenko, Yury
    T. Shevchenko Kyiv National University, Kyiv, Ukraine.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Guaranteed estimation for inverse problems in electromagnetics and acoustics2016In: Proceedings of the 2016 18th International Conference on Electromagnetics in Advanced Applications, ICEAA 2016, 2016, p. 374-377, article id 7731403Conference paper (Refereed)
    Abstract [en]

    The analysis is performed and theorems are formulated concerning general form of guaranteed estimates of linear functionals from unknown data of Helmholtz transmission problems arising in electromagnetics and acoustics of inhomogeneous dielectric media.

  • 30.
    Nakonechnyi, Oleksandr
    et al.
    National Taras Shevchenko University, Kiev, Ukraine .
    Podlipenko, Yuri
    National Taras Shevchenko University, Kiev, Ukraine .
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    The Minimax Estimation Method for a Class of Inverse Helmholtz Transmission Problems2019In: Minimax Theory and its Applications, ISSN 2199-1413, Vol. 4, no 2, p. 305-328Article in journal (Refereed)
    Abstract [en]

    We present complete mathematical statements and perform detailed investigations of the minimax estimation problems of unknown data for the Helmholtz transmission problems from indirect noisy observations of their solutions. We construct optimal, in certain sense, estimates, which are called minimax mean-square estimates, of the values of linear functionals from unknown data. It is established that when unknown data and correlation functions of errors in observations belong to special sets, the minimax mean square estimates are expressed via solutions to certain transmission problems for systems of Helmholtz equations. We prove that these systems are uniquely solvable. Several possible generalizations of the techniques and results are proposed including applications to the problems with incomplete data and pointwise observations. 

  • 31.
    Podlipenko, Y. K.
    et al.
    Taras Shevchenko National University of Kyiv, Kyiv, Ukraine.
    Nakonechny, A. G.
    Taras Shevchenko National University of Kyiv, Kyiv, Ukraine.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Guaranteed estimation of solutions to Helmholtz problems from pointwise noisy observations2016In: Proceedings of the International Conference Days on Diffraction, DD 2016, 2016, p. 336-339, article id 7756869Conference paper (Refereed)
    Abstract [en]

    The theorems on a general form of guaranteed estimates of linear functionals from unknown solutions of Helmholtz transmission problems are formulated in the case of pointwise noisy observations of these solutions.

  • 32.
    Podlipenko, Y.
    et al.
    Taras Shevchenko National University, Kyiv, Ukraine.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Guaranteed estimation of solutions to transmission problems for Helmholtz equation with uncertain data from their indirect noisy observations2016In: 2016 URSI International Symposium on Electromagnetic Theory (EMTS), IEEE conference proceedings, 2016, p. 93-95Conference paper (Refereed)
    Abstract [en]

    We investigate the estimation problems of linear functionals from solutions to transmission problems for Helmholtz equation with inexact data. The right-hand sides of equations entering the statements of transmission problems and the statistical characteristics of observations errors are supposed to be unknown and belonging to the certain sets. It is shown that the linear mean square estimates of the above-mentioned functionals and estimation errors are expressed via solutions to the systems of transmission problems of the special type.

  • 33.
    Podlipenko, Y.
    et al.
    Kiev University, Kiev, Ukraine.
    Shestopalov, Yury V.
    arlstad University, Karlstad, Sweden.
    Guaranteed Estimates of Functionals from Solutions and Data of Interior Maxwell Problems Under Uncertainties2013In: Springer Proceedings in Mathematics & statistics, ISSN 2194-1017, E-ISSN 2194-1009, Vol. 52, p. 135-167Article in journal (Refereed)
    Abstract [en]

    We are looking for linear with respect to observations optimal estimates of solutions and right-hand sides of Maxwell equations called minimax or guaranteed estimates. We develop constructive methods for finding these estimates and estimation errors which are expressed in terms of solutions to special variational equations and prove that Galerkin approximations of the obtained variational equations converge to their exact solutions.

  • 34.
    Podlipenko, Yu K.
    et al.
    Faculty of Cybernetics, Taras Shevchenko National University of Kyiv, Kiev, Ukraine.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Guaranteed estimation of solutions to Helmholtz transmission problems with uncertain data from their indirect noisy observations2017In: Radio Science, ISSN 0048-6604, E-ISSN 1944-799X, Vol. 52, no 9, p. 1129-1139Article in journal (Refereed)
    Abstract [en]

    We investigate the guaranteed estimation problem of linear functionals from solutions to transmission problems for the Helmholtz equation with inexact data. The right-hand sides of equations entering the statements of transmission problems and the statistical characteristics of observation errors are supposed to be unknown and belonging to certain sets. It is shown that the optimal linear mean square estimates of the above mentioned functionals and estimation errors are expressed via solutions to the systems of transmission problems of the special type. The results and techniques can be applied in the analysis and estimation of solution to forward and inverse electromagnetic and acoustic problems with uncertain data that arise in mathematical models of the wave diffraction on transparent bodies.

  • 35.
    Podlipenko, Yuri
    et al.
    T. Shevchenko Kyiv National University, Kyiv, Ukraine.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Mixed variational approach to finding guaranteed estimates from solutions and right-hand sides of the second-order linear elliptic equations under incomplete data2016In: Minimax Theory and its Applications, ISSN 2199-1413, Vol. 1, no 2, p. 197-244Article in journal (Refereed)
    Abstract [en]

    We investigate the problem of guaranteed estimation of values of linear continuous functionals defined on solutions to mixed variational equations generated by linear elliptic problems from indirect noisy observations of these solutions. We assume that right-hand sides of the equations, as well as the second moments of noises in observations are not known; the only available information is that they belong to given bounded sets in the appropriate functional spaces. We are looking for linear with respect to observations optimal estimates of solutions of aforementioned equations called minimax or guaranteed estimates. We develop constructive methods for finding these estimates and estimation errors which are expressed in terms ofsolutions to special mixed variational equations and prove that Galerkin approximations of the obtained variational equations converge to their exact solutions. We study also the problem of guaranteed estimation of right-hand sides of mixed variational equations.

  • 36.
    Samokhin, A. B.
    et al.
    Moscow Technological University (MIREA), Moscow, Russian Federation.
    Samokhina, A. S.
    Institute of Control Sciences, Moscow, Russian Federation.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Fast algorithms for the solution of volume singular integral equations of electromagnetics2017In: 2017 International Conference on Electromagnetics in Advanced Applications (ICEAA), Institute of Electrical and Electronics Engineers Inc. , 2017, p. 776-778, article id 8065364Conference paper (Refereed)
    Abstract [en]

    Fast algorithms for the solution of volume singular integral equations of electromagnetics are presented. Numerical results are demonstrated that confirm efficiency of the developed fast computational algorithms.

  • 37.
    Samokhin, Alexander
    et al.
    Moscow Technological University (MIREA), Moscow, Russia.
    Samokhina, Anna
    Trapeznikov Institute of Control Sciences of the Russian Academy of Sciences, Moscow, Russia.
    Shestopalov, Yury
    Moscow Technological University (MIREA), Moscow, Russia.
    Analysis and solution method for problems of electromagnetic wave scattering on dielectric and perfectly conducting structures2017In: Differential equations, ISSN 0012-2661, E-ISSN 1608-3083, Vol. 53, no 9, p. 1165-1173Article in journal (Refereed)
    Abstract [en]

    Problems of electromagnetic wave scattering on 3D dielectric structures in the presence of bounded perfectly conducting surfaces are reduced to a system of singular integral equations. We study this system mathematically and suggest a numerical solution method.

  • 38.
    Samokhin, Alexander
    et al.
    Moscow Technical University MIREA, Moscow, Russia.
    Samokhina, Anna
    Trapeznikov Institute of Control Sciences of the Russian Academy of Sciences, Moscow, Russia.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Discretization Methods for Three-Dimensional Singular Integral Equations of Electromagnetism2018In: Differential equations, ISSN 0012-2661, E-ISSN 1608-3083, Vol. 54, no 9, p. 1225-1235Article in journal (Refereed)
    Abstract [en]

    Theorems providing the convergence of approximate solutions of linear operator equations to the solution of the original equation are proved. The obtained theorems are used to rigorously mathematically justify the possibility of numerical solution of the 3D singular integral equations of electromagnetism by the Galerkin method and the collocation method.

  • 39.
    Samokhin, Alexander
    et al.
    Moscow State Technical University of Radio Engineering and Automation, Moscow, Russian Federation.
    Shestopalov, Yury V.
    Karlstad University, Karlstad, Sweden.
    Kobayashi, Kazuya
    Chuo University, Tokyo, Japan.
    Stationary iteration methods for solving 3D electromagnetic scattering problems2013In: Applied Mathematics and Computation, ISSN 0096-3003, E-ISSN 1873-5649, Vol. 222, p. 107-122Article in journal (Refereed)
    Abstract [en]

    Generalized Chebyshev iteration (GCI) applied for solving linear equations with nonselfadjoint operators is considered. Sufficient conditions providing the convergence of iterations imposed on the domain of localization of the spectrum on the complex plane are obtained. A minimax problem for the determination of optimal complex iteration parameters is formulated. An algorithm of finding an optimal iteration parameter in the case of arbitrary location of the operator spectrum on the complex plane is constructed for the generalized simple iteration method. The results are applied to numerical solution of volume singular integral equations (VSIEs) associated with the problems of the mathematical theory of wave diffraction by 3D dielectric bodies. In particular, the domain of the spectrum location is described explicitly for low-frequency scattering problems and in the general case. The obtained results are discussed and recommendations concerning their applications are given.

  • 40.
    Sheina, E. A.
    et al.
    Lomonosov Moscow State University, Russian Federation.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Smirnov, A. P.
    Lomonosov Moscow State University, Russian Federation.
    Planning and processing of measurements in a waveguide aimed at determination of permittivity of dielectric inclusion2017In: 2017 Progress In Electromagnetics Research Symposium - Fall (PIERS - FALL), Electromagnetics Academy , 2017, p. 1866-1871Conference paper (Refereed)
    Abstract [en]

    The methods are developed for reconstructing permittivity of the inclusion in a rectangular waveguide with perfectly conducting walls by comparing the results of multifrequency measurements of the principal waveguide mode transmission coefficient with the data obtained from numerical solution to Maxwell's equations. Optimal schemes for experimentation and processing of the obtained data are proposed on the basis of comparison of experimental data with closed-form solutions for cases of empty waveguide and the waveguide containing a uniform diaphragm.

  • 41.
    Sheina, E. A.
    et al.
    Lomonosov Moscow State University, Russian Federation.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Smirnov, A. P.
    Lomonosov Moscow State University, Russian Federation.
    Ufimtsev, M. V.
    Lomonosov Moscow State University, Russian Federation.
    FDTD solution of reconstructing permittivity of a dielectric inclusion in a waveguide taking into account measurement inaccuracy2017In: Progress in Electromagnetics Research Symposium, Electromagnetics Academy , 2017, p. 3188-3195Conference paper (Refereed)
    Abstract [en]

    Wave propagation in a rectangular waveguide with perfectly conducting walls containing a parallel-plane dielectric diaphragm and a small inclusion is modeled using a numerical solution to Maxwell's equations. The methods are developed for reconstructing permittivity of the inclusion from the transmission coefficient of the principal waveguide mode taking into account experimental error. The results determined by these methods are compared with experimental data obtained for a homogeneous diaphragm.

  • 42.
    Sheina, E. A.
    et al.
    Lomonosov Moscow State University, Russian Federation.
    Smirnov, A. P.
    Lomonosov Moscow State University, Russian Federation.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Influence of standing waves on the solution of the inverse problem of reconstructing parameters of a dielectric inclusion in a waveguide2016In: 2016 URSI International Symposium on Electromagnetic Theory (EMTS), IEEE conference proceedings, 2016, p. 643-646Conference paper (Refereed)
    Abstract [en]

    We consider numerical determination of the dielectric media parameters of inclusions in a waveguide of rectangular cross-section from the transmission coefficient. We develop and apply computer codes implementing the FDTD algorithm for numerical solution of the nonstationary Maxwell equations with perfectly matched layer (PML) absorbing boundary conditions using the Berenger layout. We estimate parameter ranges providing the necessary accuracy for solving forward and inverse scattering problems for waveguides with inclusions. Aposteriori estimate of the amplitude of higher-order evanescent waves is obtained and their influence on the choice of parameters of the numerical method is determined.

  • 43.
    Sheina, E. A.
    et al.
    Lomonosov Moscow State University, Moscow, Russian Federation.
    Smirnov, A. P.
    Lomonosov Moscow State University, Moscow, Russian Federation.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Optimization of the boundary conditions and computational parameters for the FDTD solution of the inverse problem of reconstructing permittivity of a dielectric inclusion in a waveguide2016In: 2016 Progress In Electromagnetics Research Symposium, PIERS 2016 - Proceedings, 2016, p. 211-216, article id 773429Conference paper (Refereed)
    Abstract [en]

    Wave propagation in a waveguide of rectangular cross section with perfectly conducting wall containing an inhomogeneous dielectric insert in the form of a parallel-plane diaphragm with an inclusion is simulated numerically. The permittivity of the inclusion is a quantity to be restored from as little information about the scattered field as possible using FDTD numerical solution of Maxwell’s equations with nonlocal multimode scattering boundary conditions. The optimal number of higher-order evanescent waves and the size of the computational waveguide domain are found using the series of numerical experiments.

  • 44.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Complex waves in a dielectric waveguide2018In: Wave motion, ISSN 0165-2125, E-ISSN 1878-433X, Vol. 82, p. 16-19Article in journal (Refereed)
    Abstract [en]

    Existence of two families of symmetric complex waves in a dielectric waveguide of circular cross section is proved. Eigenvalues of the associated Sturm–Liouville problem on the half-line are determined. 

  • 45.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    How to overcome nonuniqueness of permittivity reconstruction in inverse waveguide problems2018Conference paper (Refereed)
  • 46.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    Justification of mathematical imaging technique for the permittivity determination of layered dielectrics in a waveguide2019In: 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2019, p. 0143-0146Conference paper (Refereed)
    Abstract [en]

    An introduction to mathematical imaging technique for solving inverse scattering problems is given. Applications are considered to inverse waveguide problems of recontructing permittivity of layered dielectric inclusions. The solution is justified of the inverse microwave imaging by establishing one-to-one correspondence between the sought quantities and the measured noisy data.

  • 47.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Methods for verifying solvability of the permittivity reconstruction in canonical waveguide inverse problems2017In: 2017 XXXIIND GENERAL ASSEMBLY AND SCIENTIFIC SYMPOSIUM OF THE INTERNATIONAL UNION OF RADIO SCIENCE (URSI GASS), Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 1-2Conference paper (Refereed)
    Abstract [en]

    We present a summary of mathematical methods that enable one to study and reveal the properties of the transmission coefficient as a function of problem parameters aimed at solution to some canonical waveguide inverse problems. The results are based on application of the theory of functions of several complex variables and singularities of differentiable mappings and lead to substantial improvement of the available techniques for permittivity reconstruction of material samples in waveguides.

  • 48.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Mathematics.
    On a Method of Solution to Dispersion Equations in Electromagnetics2019In: 2019 URSI Asia-Pacific Radio Science Conference (AP-RASC), New Dehli, 2019, article id 8738297Conference paper (Refereed)
    Abstract [en]

    A possible general approach to the analysis of dispersion equations (DEs) of electromagnetics is presented. The method takes into account the known explicit forms of DEs describing eigenoscillations and normal waves in layered structures and is based on the development of the notion of generalized cylindrical polynomials. The approach enables one to complete rigorous proofs of existence and determine domains of localization of the DE roots and validate iterative numerical solution techniques.

  • 49.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    On a Perspective of Discovering Wave Interaction in Canonical Open Metal-Dielectric Waveguides2018In: Proceedings of 2018 International Conference on Electromagnetics in Advanced Application (ICEAA), Piscataway, New Jersey, USA: IEEE conference proceedings, 2018, p. 72-75, article id 8520368Conference paper (Refereed)
    Abstract [en]

    A possibility of the wave interaction is demonstrated for canonical types of open metal-dielectric waveguides: a dielectric rod of circular cross section and a perfectly conducting circular cylinder covered by a concentric layer of dielectric, a Goubau line. The results and technique that apply rigorous analysis of dispersion equations and determination of Morse critical points admit extension to other types of guiding structures.

  • 50.
    Shestopalov, Yury
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    On a spectrum of complex waves in open metal-dielectric waveguides [О спектре комплексных волн в открытых металлических диэлектрических волноводах]2018In: Современные методы теории краевых задач: материалы международной конференции, посвящённой 90-летию Владимира Александровича Ильина (2-6 мая 2018 г., Москва): Понтрягинские чтения - XXIX / [ed] Budak Alexander Borisovich [Будак Александр Борисович], Moscow: Moscow State University Press , 2018, p. 243-244Conference paper (Refereed)
123 1 - 50 of 115
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