Search results for: electromagnetic waves

JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS
Journals 
Calculation methods of interaction of electromagnetic waves with objects of complex geometries
PublicationModeling of the electromagnetic interaction with different homogeneous or inhomogeneous objects is a fundamental and important problem. It is relatively easy to solve Maxwellequations analytically when the scattering object is spherical or cylindrical, for example. However, when it loses these properties all that is left for us is to useapproximation models, to acquire the solution we need. Modeling of complex, nonspherical,...

Scattering by parallel cylindrical posts with conducting strips. W: Pro gress in electromagnetics research. Ed. J.A. Kong. Cambridge, Massachusett/ USA/: EMW Publ.**2003 s. 305333, 18 rys. 5 tabl. bibliogr. 14 poz. Electromagnetic Waves. PIER [nr] 43. Rozpraszanie na równoległych metalizowanych obiektach cylindrycznych.
PublicationRozwinięto teorię rozpraszania fali elektromagnetycznej w obszarach otwartych i zamkniętych na metalizowanych obiektach cylindrycznych przy użyciuzmodyfikowanej procedury iteracyjnej i metody dopasowania rodzajów. W wynikuanalizy uzyskano pole rozproszone w przypadku struktur otwartych oraz odpowiedzi częstotliwościowe współczynników odbicia i transmisji w prostokątnych złączach falowodowych. Obrót i przemieszczenie...

Electromagnetic plane wave scattering from a cylindrical object with an arbitrary cross section using a hybrid technique
PublicationA hybrid technique combining finiteelement and modematching methods for the analysis of scattering problems in open and closed areas is presented. The main idea of the analysis is based on the utilization of the finiteelement method to calculate the post impedance matrix and combine it with external excitation. The discrete analysis, which is the most time and memoryconsuming, is limited here only to the close proximity of...

Fundamental properties of solutions to fractionalorder Maxwell's equations
PublicationIn this paper, fundamental properties of solutions to fractionalorder (FO) Maxwell's equations are analysed. As a starting point, FO Maxwell's equations are introduced in both time and frequency domains. Then, we introduce and prove the fundamental properties of electromagnetic field in FO electromagnetics, i.e. energy conservation, uniqueness of solutions, and reciprocity. Furthermore, the algorithm of the plane wave simulation...

Design of UWB coplanar antenna with reduced ground plane
PublicationW artykule przedstawiono projekt kompaktowej anteny szerokopasmowej złożonej z dwóch kołowych pasków koplanarnych ograniczających szczelinę o podobnym kształcie. Antena zasilona była z 50 Ω linii trójpaskowej. Przeprowadzono badania wpływu zewnętrznego paska na pasmo anteny. Zaprojektowana antena została zbadana eksperymentalnie pokazując bardzo dobre parametry: w paśmie 1.715.5GHz uzyskano S11 < −10dB. Antena charakteryzowała...

Investigations of nonreciprocal devices employing cylindrical ferrite coupled line junction
PublicationArtykuł opisuje wykorzystanie cylindrycznej sekcji ferrytowych linii sprzężonych do realizacji układów niewzajemnych. W artykule opisano proces projektowy izolatora ferrytowego wykorzystującego badaną sekcję oraz planarne układy zasilające. Uzyskane z symulacji wyniki zostały zweryfikowane eksperymentalnie.

Scattering by an array of conducting, lossy dielectric, ferrite and pseudochiral cylinders.
PublicationOpisano metodę analizy rozpraszania fali elektromagnetycznej w systemach zawierających cylindryczne pręty dielektryczne, metalowe, ferytowe i pseudochiralne i wykorzystanie w/w metody w problemach zamkniętych i znajdowanie macierzy rozpraszania wieloportowych złączy falowodowych oraz w problemach otwartych i badanie charakterystyk rozpraszania zarówno w strefie dalekiej jaki bliskiej.

Recurrence scheme for FDTDcompatible discrete Green's function derived based on properties of Gauss hypergeometric function
PublicationIn this paper, the formulation of onedimensional FDTD (Finitedifference timedomain)compatible discrete Green's function (DGF) is derived based on the Gauss hypergeometric function (GHF). The properties of GHF make it possible to derive the recurrence scheme only in the time domain for the DGF generation. Furthermore, this recurrence scheme is valid for any stable timestep size and can be implemented using standard numerical...

Design and optimization of a novel miniaturized lowprofile circularly polarized wideslot antenna
PublicationThis paper presents a novel structure of a compact circularly polarized (CP) antenna. CP is obtained using a parasitic quasirectangular strip placed coplanar to the feedline. A ground plane perturbation combined with the asymmetric geometry of the coplanar waveguide ground planes is utilized to excite additional CP modes. All antenna dimensions are rigorously optimized to achieve the best possible performance in terms of the impedance...

Rapid multiobjective design of integrated onchip inductors by means of Pareto front exploration and design extrapolation
PublicationIdentification of the best tradeoffs between conflicting design objectives allows for making educated design decisions as well as assessing suitability of a given component or circuit for a specific application. In case of inductors, the typical objectives include maximization of the quality factor and minimization of the layout area, as well as maintaining a required inductance at a given operating frequency. This work demonstrates...

Resonance microstrip structure with patch of arbitrary convex geometry with the use of field matching technique
PublicationAn analysis of the resonance frequency problem of planar microstrip structure with patch of arbitrary convex geometry is presented. A fullwave analysis is employed utilizing a combination of Galerkin’s moment method and field matching technique. In this approach, a field matching technique is adopted to calculate the patch surface current densities, and next the method of moments is utilized to calculate resonance frequencies...

Finite element/modematching analysis of ferrite/dielectric line junctions of arbitrary crosssection
PublicationThis paper is focused on the analysis of line junctions obtained as a cascade of dielectric and ferrite guides of arbitrary crosssection. The main application of such structures is nonreciprocal devices such as isolators, circulators, or phase shifters. The efficient finite element/modematching approach is proposed to the analysis of such structures. In this approach, thefiniteelementmethod is applied todetermine propagation...

Lefthanded propagation characteristics of a dielectric and metalloaded periodic circular waveguide
PublicationIn this paper, a periodic dielectric/metallic rod is located in a circular waveguide to obtain lefthanded operation. Two geometries of the dielectric/metallic rod are proposed and examined. The dispersion characteristics of the investigated waveguides are obtained using a surface impedance model. Moreover, equivalent circuit models are proposed allowing for calculation of the dispersion characteristics and scattering parameters...

GPR simulations for diagnostics of a reinforced concrete beam
PublicationThe most popular technique for modelling of an electromagnetic field, the finite difference time domain (FDTD) method, has recently become a popular technique as an interpretation tool for ground penetrating radar (GPR) measurements. The aim of this study is to detect the size and the position of damage in a reinforced concrete beam using GPR maps. Numerical simulations were carried out using the finite difference time domain...

Evaluation of propagation parameters of open guiding structures with the use of complex root finding algorithms
PublicationAn efficient complex root tracing algorithm is utilized for the investigation of electromagnetic wave propagation in open guiding structures. The dispersion characteristics of propagated and leaky waves are calculated for a couple of chosen waveguides. The efficiency of the root tracing algorithm is discuses and compared to a global root finding algorithm.

Underwater Acoustic Imaging of the Sea
PublicationAcoustic waves are a carrier of information mainly in environments where the use of other types of waves, for example electromagnetic waves, is limited. The term acoustical imaging is widely used in the ultrasonic engineering to imaging areas in which the acoustic waves propagate. In particular, ultrasound is widely used in the visualization of human organs  ultrasonography (Nowicki, 2010). Expanding the concept, acoustical imaging...

A highaccuracy method of computation of xray waves propagation through an optical system consisting of many lenses
PublicationThe propagation of Xray waves through an optical system consisting of many Xray refractive lenses is considered. Two differential equations are contemplated for solving the problem for electromagnetic wave propagation: first – an equation for the electric field, second – an equation derived for a complex phase of an electric field. Both equations are solved by the use of a finitedifference method. The simulation error is estimated...

Interactive Application for Visualization of the Basic Phenomena in RF and Microwave Devices
PublicationAn interactive computer application visualizing the basic phenomena in RF and microwave devices is presented. Such kind of educational package can be a very helpful tool for the students as well as for the teachers (of electronics and related ﬁelds). This paper is focused on three exemplary problems only and involves: movement of electric charge, ﬁltering of electromagnetic waves and interference phenomena in antenna arrays. The...

The finite difference methods of computation of Xrays propagation through a system of many lenses
PublicationThe propagation of Xray waves through an optical system consisting of many beryllium Xray refrac tive lenses is considered. In order to calculate the propagation of electromagnetic in the optical sys tem, two differential equations are considered. First equation for an electric field of a monochromatic wave and the second equation derived for complex phase of the same electric The propagation of Xray waves through an optical system...

GPR investigation of the strengthening system of a historic masonry tower
PublicationIn this paper the condition assessment of the strengthening system of a masonry tower was carried out by the GPR method. The study provided unique experimental data acquired during measurements of the reinforced concrete frame embedded in masonry walls. Conducted numerical and experimental investigations were focused on the phenomenon of the diffractionrefraction scattering of the electromagnetic energy. A hyperbola resulting...

Global Complex Roots and Poles Finding Algorithm Based on Phase Analysis for Propagation and Radiation Problems
PublicationA flexible and effective algorithm for complex roots and poles finding is presented. A wide class of analytic functions can be analyzed, and any arbitrarily shaped search region can be considered. The method is very simple and intuitive. It is based on sampling a function at the nodes of a regular mesh, and on the analysis of the function phase. As a result, a set of candidate regions is created and then the roots/poles are verified...

Factors Shaping the Working Environment, Living Conditions and Recreation on Board Ship
PublicationA seagoing ship is a working place, an accommodation space and a recreation area at the same time. Being exposed to harsh physical conditions, it must satisfy different requirements. The human organism and its qualities become a point of reference here; consequently, the functions and spatial arrangement and interiors of a ship must be subordinated to its needs. The organisation of the space in contemporary ships meant for human...

A highaccuracy complexphase method of simulating Xray propagation through a multilens system
PublicationThe propagation of Xray waves through an optical system consisting of many Xray refractive lenses is considered. For solving the problem for an electromagnetic wave, a finitedifference method is applied. The error of simulation is analytically estimated and investigated. It was found that a very detailed difference grid is required for reliable and accurate calculations of the propagation of Xray waves through a multilens...

Application of the Monte Carlo algorithm for solving volume integral equation in light scattering simulations
PublicationVarious numerical methods were proposed for analysis of the light scattering phenomenon. Important group of these methods is based on solving the volume integral equation describing the light scattering process. The popular method from this group is the discrete dipole approximation (DDA). DDA uses various numerical algorithms to solve the discretized integral equation. In the recent years, the application of the Monte Carlo (MC)...

Data obtained by numerical simulation for Xray focusing using a finite difference method
Open Research DataThe propagation of Xray waves through an optical system consisting of many Xray refractive lenses is considered. For solving the problem for an electromagnetic wave, a finitedifference method is applied.

Data obtained by computation for Xray focusing using oriented Gaussian beams
Open Research DataThe propagation of Xray waves through an optical system consisting of several Xray refractive lenses is considered. Gaussian beams are exact solutions of the paraxial equation. The Helmholtz equation describes the propagation of a monochromatic electromagnetic wave. Since the widths of the beams are much larger than the wavelength of Xrays, Gaussian...

Rafał Lech dr hab. inż.
PeopleIEEE Senior Member #92122578 Rafal Lech was born in Elblag, Poland, in 1977. He received the M.Sc.E.E. and Ph.D. degrees (with honors) from the Gdansk University of Technology, Gdansk, Poland, in 2001 and 2007, respectively. He is currently with the Faculty of Electronics, Department of Microwave and Antenna Engineering, Telecommunications and Informatics, Gdansk University of Technology. His main research interests are electromagneticwave...

GENERAL DYNAMIC PROJECTING OF MAXWELL EQUATIONS
PublicationA complete – system of Maxwell equations is splitting into independent subsystems by means of a special dynamic projecting technique. The technique relies upon a direct link between field components that determine correspondent subspaces. The explicit form of links and corresponding subspace evolution equations are obtained in conditions of certain symmetry, it is illustrated by examples of spherical and quasionedimensional waves.

Application of gpr method in diagnostics of reinforced concrete structures
PublicationThis paper presents an application of the ground penetration method (GPR) for diagnostics of reinforced concrete structures. In situ measurements were conducted for three civil engineering structures: the ground floor structure, the abutment of the railway viaduct and the concrete well. The dual polarized ground penetrating radar with the antenna operating at a center frequency of 2 GHz was used for GPR surveys. Three different...