Features of Radiation of Electromagnetic Waves from a Thin Electric Antenna in a Planar Waveguide with Inhomogeneous Filling

We consider the problem of radiation of electromagnetic waves from a thin electric antenna located in a planar waveguide with perfectly conducting walls filled with an inhomogeneous dielectric. Cases where the antenna is fed by a time-harmonic e.m.f. and a bell-shaped impulse signal are analyzed. The current distribution along the antenna, its input admittance, the longitudinal component of the electric field, and the total complex power of the antenna are calculated numerically. We compare the antenna characteristics for waveguides with homogeneous and inhomogeneous filling.     

Radiation from an Electric Dipole Surrounded by a Plasma Cylinder with a Cavity

We solve the problem of the influence of a small-radius (ka1) isotropic plasma cylinder with a coaxial free-space cavity on the radiation from a source of electromagnetic waves to an outer region of free space. Conditions of the resonance radiation are obtained and characteristics of this radiation as functions of the relative size of the cavity are studied. We show that the resonance frequency splits into two frequencies such that the transmission coefficients at these frequencies can exceed the resonance transmission coefficient for the plasma cylinder without a cavity. The results obtained are compared with the case of emission from a two-layer spherical plasma resonator.     

无限长非均匀圆柱对平面波散射的彩虹特性研究

以梯度折射率聚合物光纤为例,利用非均匀柱粒子的洛伦茨-米氏(Lorenz-Mie)理论和德拜(Debye)级数研究了非均匀柱粒子的一阶、二阶彩虹强度分布特点.针对不同阶次彩虹间存在相干现象这一特点,提出了低通、带通滤波和逆快速傅里叶变换(IFFT)方法,将各阶彩虹从相互干涉的强度分布中分离重建出来,并且与Debye级数模拟的结果进行了比较,吻合得很好;讨论了分层柱粒子的双重一阶彩虹现象,利用Lorenz-Mie理论和Debye级数模拟了双重一阶彩虹的强度分布.     

Electromagnetic Waves in a Waveguide with Periodically Modulated Magnetodielectric Filling

Optics and Spectroscopy - The propagation of electromagnetic waves in an ideal regular waveguide with the magnetodielectric filling periodically modulated in space and time is studied. It is...     

Field of an Electric Dipole Surrounded by a Small Plasma Spheroid with a Cavity

We obtain and analyze a solution of the boundary-value problem for the field of an electric dipole centered in a vacuum cavity inside a small plasma spheroid. The influence of the cavity size on the field enhancement in an outer vacuum region is analyzed as a function of the curvature of the plasma-spheroid surface. The results are compared with the case of a sphere with similar cavity.__________Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 48, No. 2, pp. 142–151, February 2005     

Radiation of an Electric Dipole from a Small Plasma Spheroid

We obtain and analyze an analytical solution of the boundary-value problem of the field of an electric dipole located in a small spheroid filled with a cold isotropic plasma. The conditions of resonant amplification of the field in vacuum are studied for various shapes and curvatures of the plasma spheroid. It is shown that for a certain spheroid shape, the resonant amplification increases several times compared with the case of spherical plasma environment. The obtained results are compared with the resonant radiation of a dipole from a narrow elliptical plasma cylinder.     

Diffraction of an Electromagnetic Wave on a Dielectric Rod in a Rectangular Waveguide. A Method of Partial Waveguide Filling

Russian Physics Journal - A variant of the method of partial waveguide filling is considered in which a sample is put into a waveguide through holes in wide waveguide walls at the distance equal to...     

Self-Rotation of Particles with a Photoinduced Electric Dipole Moment

Technical Physics - We consider the realization of rotation of particles with a photoinduced dipole moment in the absence of an external field source. The effects considered here are based on the...     

Plane Symmetric Inhomogeneous Cosmological Models with a Perfect Fluid in General Relativity

In this paper we investigate a class of solutions of Einstein equations for the plane- symmetric perfect fluid case with shear and vanishing acceleration. If these solutions have shear, they must necessarily be non-static. We examine the integrable cases of the field equations systematically. Among the cases with shear we find three classes of solutions. PACS No.: 04.20.-q.     

Excitation of Electromagnetic Waves in a Plane Waveguide with Anisotropic Upper Wall

We solve the problem of propagation of electromagnetic ULF waves in a plane waveguide with anisotropic upper wall from an arbitrary source with allowance for an arbitrary inclination of the magnetic field. The procedure for calculating magnetic components of the signal radiated by horizontal and vertical dipoles is developed in detail. The solution is presented in the form of the Fourier–Bessel transform of the desired field components. Impedance-type boundary conditions were used for an arbitrary inclination of the magnetic field. The obtained solutions can be used for interpreting experiments on measuring the spectra of ULF electromagnetic noise in various geographical regions and calculating parameters of ULF signals from controlled sources.     

Propagation of ULF Radiation from an Artificial Ionospheric Source in a 3D Inhomogeneous MHD Waveguide

Radiophysics and Quantum Electronics - We analyze the propagation of electromagnetic waves of the ultralow-frequency (ULF) range emitted by an artificial ionospheric source arising in the...     

Evolution of a Diffusion Channel in an Inhomogeneous Electric Field of the KrF-Laser Pump Discharge

Russian Physics Journal - The results of studying the 2D-simulation of evolution of a diffusion channel in the KrF-laser pump discharge initiated by the pin on the cathode surface are presented. It...     

Reflection and Transmission of a Polarized Vortex Beam by an Inhomogeneous Anisotropic Plane Layer

Radiophysics and Quantum Electronics - We consider oblique incidence of a vortex polarized beam on an inhomogeneous anisotropic plane layer of an artificial metamaterial. A matrix model of beam...     

Micromagnetic Structures Induced by an Inhomogeneous Electric Field in Magnetically Uniaxial Films with a Flexo-Magnetoelectric Effect

Physics of the Solid State - The features of the manifestation of the flexo-magnetoelectric effect in magnetically uniaxial films under the local influence of an electric field on their surface are...     

Numerical and Asymptotic Solution of the Problem of Oscillations of an Inhomogeneous Waveguide with an Annular Crack of Finite Width

Acoustical Physics - The problem of waves in an inhomogeneous cylindrical waveguide with an annular crack is considered. A system of integral equations with hypersingular kernels is obtained for...     

Streamer Breakdown with Runaway Electrons Forming Diffuse Discharges in an Inhomogeneous Electric Field

Russian Physics Journal - The results of experimental investigations of formation of diffuse nanosecond discharges in a nonuniform electric field in air and other gases at the pressures within...     

Gauge Invariance of a Time-Dependent Harmonic Oscillator in Magnetic Dipole Approximation

A manifestly gauge-invariant formulation of non-relativistic quantum mechanics is applied to the case of time-dependent harmonic oscillator in the magnetic dipole approximation. A general equation for obtaining gauge-invariant transition probability amplitudes is derived.