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The design of thinned planar microstrip arrays under specific constraints concerning the impedance-matching condition of the array elements and the radiation pattern is presented. The radiation characteristics of the structure are extracted by applying the method-of-moments. The array design is based on a novel optimization method, which is a modified version of the boolean particle swarm optimization that employs velocity mutation (BPSO-vm). Apart from the optimization of the array geometry, the proposed method is applicable to other discrete-variable optimization problems. Moreover, the planar array design is coped with by means of other techniques, namely, a binary coded Genetic Algorithm, the binary Particle Swarm Optimization, and the Boolean PSO. The comparison of the above methods and the BPSO-vm shows the efficiency of the proposed technique. Index Terms--Artificial immune system, particle swarm optimization (PSO), planar arrays, thinned arrays.

In this paper, the CFL conditions of several 2-D finite integration (FI) methods on regular triangular meshes are derived. A piecewise uniform element allows a time step that is twice as large as that for the Whitney element. Index Terms--Electromagnetic wave, finite integration (FI) technique, piecewise uniform element, stability, Whitney element.

The influence of stratified earth on the wave propagation characteristics of overhead conductors is analyzed, using a generalized two-layer earth model of varying electromagnetic characteristics. A systematic comparison to simpler stratified earth models is presented, showing the differences in the propagation characteristics. Index Terms--Earth return admittance, earth return impedance, multiconductor lines, nonhomogenous earth.

The iterative absorbing boundary condition (IABC) is a flexible and accurate way of truncating the computational domain for finite-element analysis of electromagnetic wave scattering, particularly when the element orders are adjusted carefully to minimize overall computational cost. The method is here extended to antenna problems, taking into account the feed modeling. Discretization and boundary errors in the feed reflection coefficient or in the radiated field are balanced during the iteration. Results for a waveguide terminated in a flange, a horn antenna, and a microstrip patch antenna demonstrate the accuracy of the approach, and the computational savings relative to the use of the same element order during the whole iteration. Index Terms--Adaptive absorbing boundary condition, antenna feeds, antenna radiation patterns, antennas, boundary value problems, finite-element methods.

The overview summarizes the main electromagnetic activities in Russia since the 13th Electromagnetic Launch Technology Symposium in 2006. This research has been focused on the development and improvement of electric-discharge launchers, railguns, and electrothermal-chemical launchers. Research efforts have been directed toward studying the physical phenomena and processes limiting the attainment of high velocities and life time of launchers. Considerable attention has been paid to solving problems related to material erosion, the manufacture of new materials and their testing in high-current arc discharges and the search for new applications of launchers in science and engineering. Index Terms--Electrodischarge launcher, electromagnetic launcher, electrothermal-chemical launcher.

A nanofiber nonwoven textile with metallic magnetic material coating was fabricated, and the effect of electromagnetic wave shielding was evaluated. The nanofiber nonwoven textile with an average diameter of about 500 nm was spun by electrospinning. The metallic magnetic material was coated by sputtering on the textile surface. EMI shielding effect of the textile with metallic magnetic material coating was about 90% in the GHz band. Because the textile has thin, light, flexible, and breathable characteristics, it will be versatile for various electromagnetic wave shielding applications. Index Terms--Electromagnetic wave shielding, electrospinning, metallic magnetic material, nanofiber nonwoven textile, sputtering.

Nonlinear interactions of electromagnetic waves (EMW) in magnetic nanoparticle systems at microwave frequencies were numerically simulated using rigorous mathematical models to solve the nonlinear diffraction boundary problem. The transmission coefficients [absolute value of [S.sub.12]] of arrays of ferrite spheres, depending on the normalized frequency [omega]/[gamma] ([gamma] gyromagnetic ratio), for radii of 250 mm and 0.1 mm, and separation between the spheres from 600 to 3000 nm, were determined. The increase of the interaction effects upon decreasing separation is demonstrated. The instability regions of parametric generation in the nonlinear ferrite sphere array, depending on the magnitude of the pumping wave at frequency [omega]H, are simulated using our computational algorithm of the bifurcation points of the nonlinear Maxwell's operator. With decreasing separation, i.e., increasing interaction between the spherical elements of the array, the instabilities occur at lower inputs, revealing the power sensitivity of small particle systems. Index Terms--Electromagnetic propagation in magnetic media, magnetic resonance, nanomagnets, nonlinear magnetics.

A novel implementation of periodic boundary conditions in the finite-element method is presented that is applicable to complex eigenmode analysis of the electromagnetic waves in infinite periodic media. A weighted residual finite-element (FE) model is employed to obtain the attenuation constant of evanescent/complex modes within bandgaps by analyzing only one unit cell of the structure. Plots of the imaginary and the real parts of the propagation constants versus frequency are shown which confirms the capability of the developed FE code in capturing complex modes. Index Terms--Electromagnetic bandgap, evanescent modes, finite-element method, periodic structures.

As one of possibilities of high-performance computing (HPC) technologies for electromagnetic microwave simulation, the authors have been working in development of finite-difference time-domain/finite-integration technique (FDTD/FI)-dedicated computers. There are two types of FDTD/FIT-dedicated computer architectures, extremely high-performance-oriented and large-scale simulation-oriented machines. This paper presents an improved architecture of the large-scale simulation-oriented machine for higher performance computation. Index Terms--Dataflow machine, dedicated computer, finite-difference time domain (FDTD), high-performance computation.

In order to evaluate the heating process of the target and the optimal structure of cavity in a furnace for dielectric heating, such as a microwave oven, the coupled analysis method composed of electromagnetic wave and heat conduction is a powerful tool for practical design. In this paper, we proposed the electromagnetic wave analysis method with a nonconforming mesh connection to take account of the rotational motion of the specific objects in a cavity resonator. The features such as a numerical error and convergence characteristics of the ICCOCG method were investigated, and the proposed method was applied to the dielectric heating analysis of the cavity resonator with rotation of stirrer fans. Index Terms--Finite-element method, high-frequency domain, nonconforming mesh connection, rotational motion, stirrer fan.

We present a procedure to gain significant accuracy in the finite element solution of electromagnetic scattering problems at high wavenumbers. The technique relies on the determination, at a low computational cost, of an approximate solution around the scattering obstacle, which is then used to formulate an alternative variational formulation in terms of a slowly-oscillatory amplitude. The proposed method does not require any new finite element basis functions, and can thus be easily implemented in existing finite element codes. Index Terms--Accuracy, electromagnetic scattering, finite element methods pollution, short-wave problem.

We present large-scale computations of currents induced in the human body, arising from an external low-frequency magnetic-field source. The calculations are performed using the Ex-SPFD approach; an extension of the classical SPFD approach, that can handle arbitrarily shaped magnetic-field sources and highly conductive material inside the computational domain. In order to sufficiently resolve even small organs such as the eye, very fine spatial resolution is needed. Such fine resolution results in very large systems of equations. Problems consisting of up to 200 millions of unknowns are presented. Index Terms--Biological effects of electromagnetic radiation, eddy currents, finite difference methods.

A two-dimensional self-adaptive hp finite element method (FEM) for the analysis of open region problems in electromagnetics is described. The method incorporates an iterative procedure for solving open region problems. More precisely, solution of the open problem is achieved by solving a low number of closed domain problems with the same matrix, so the computational cost for the second and subsequent problems is very small. Thus, the particularities due to the open nature of the problem are hidden and, among other advantages, self-adaptive strategies developed for conventional dosed domains and, specifically, of hp type, can be used without modifications. The hp-FEM discretization is made in terms of quadrangles/triangles of variable order of approximation supporting anisotropy and hanging nodes. The adaptive strategy is fully automatic and is based on minimizing the interpolation error (by using the projection of the error from a fine grid) delivering exponential convergence rates for the energy error, even in the presence of singularities. Index Terms--Finite element method (FEM), hp-adaptivity, radiation, scattering.

Ferrite films with a chemical composition [Ni.sub.0.2][Zn.sub.0.3][Fe.sub.2][O.sub.4] of 3 [micro]m thickness were deposited at 90[degrees]C from an aqueous solution directly on the inner ground and/or the power source layers of the following two different types of four-layered printed wiring boards (PWBs), in order to suppress the electromagnetic noise emission due to high frequency currents generated in the inner layers. PWB (a), which is the most commonly used structure, is composed of two outer signal layers, an inner ground layer, and an inner power layer. PWB (b) is composed of two outer signal layers, which contain the power supply lines as well, and two inner ground layers. Radiated emission from the ferrite film-embedded PWB (a) was successfully suppressed to be 2 to 5 dB lower than that without the ferrite film. This tendency became more prominent with increasing frequency. A similar noise suppression effect was also observed for the ferrite film-embedded PWB (b), up to 4 dB. This suggests that we can suppress radiated emission also in the case where the ground and the power planes are not placed symmetrically in the inner layers. The frequency dependence of radiated noise suppression effect by the ferrite film corresponded to the frequency dependence of transmission attenuation power ratio ([P.sub.loss]/[P.sub.in]), i.e. the suppression effect upon conducted noise due to magnetic loss characteristics of the film. This indicates that the suppression of radiated emission from the four-layered PWBs was due to the attenuation of GHz-range noise current in the ground and/or the power layers. Index Terms--Electromagnetic radiated emission, ferrite-plated film, four-layered printed wiring board, transmission attenuation power ratio.

A rigorous mathematical model of nonlinear, parametric interactions of microwave magnetostatic dipole-dipole waves and electromagnetic waves in 3-D ferrite films in waveguiding structures is developed. The 3-D nonlinear diffraction boundary problem of the full nonlinear Maxwell's equations with electrodynamical boundary conditions, complemented by the Landau-Lifshitz equation (without the exchange term) is solved. The instability of parametric excitation process of magnetostatic waves in 3-D ferrite structures is simulated by the numerical method of bifurcation analysis of the nonlinear Maxwell's operator for the 3-D boundary problem. The results show discrete maxima in the magnitude of reflected electromagnetic waves for distinct ferrite thickness values in the 1 [micro]m to 1 mm range. The mode profiles were obtained. The instability regions, depending on the bifurcation parameters, were determined, and shown to be more sensitive to the pumping power than the parametric excitation of electromagnetic waves alone. Index Terms--Ferrite films, ferrite loaded waveguides, microwave magnetic devices, nonlinear equations, nonlinear media, numerical analysis.