On boundary conditions on the curvilinear metallic surface

The impedance cylindrical surface with a discrete change of the curvature radius is considered. It is shown, that the discrete curvature change leads to the discrete change of the charge surface density, normal component of an electric field intensity and phase velocity of a current wave. The boundary conditions for the surface current density, electric field intensity components and phase velocity in the place of discrete curvature change are formulated

An excitation of the linear antenna by the relativistic charge in the circular waveguide

Excitation of a linear impedance antenna is considered in a unlimited circular wave-guide. The antenna is located in the waveguide axis and is excited by the relativistic point charge scattered at the antenna end-wall. The electric current distribution and the charge linear density distribution along the antenna are calculated. The delta-shaped re-presentation of a current on one of the antenna ends at the initial instant of time is given. The Green's function of an unlimited circular waveguide, and also the direct and inverse Fourier transform in time domain are used

An approximation algorithm to the sourcewise Green's function in the D'Alembert equation for the circular waveguide

The approximation algorithm to the tensor Green's function calculation in the D'Alembert equation for the polarization potential in the circular waveguide is proposed. The tensor Green's function is presented in the sourcewise form as the sum of the Green's function for free space and the regular part caused by reflections from the waveguide walls. The circular waveguide is a circular cylinder with a directrix in the form of a circle. The directrix in the form of a circle is approximated by a broken line in the form of an inscribed rectilinear polygon. This approximation allows one to use the method of specular reflections and get the tensor Green's function as an infinite sum of tensor divergent spherical waves with a delta-shaped front. The resulting representation of the Green's function can be used to solve the nonstationary intrinsic boundary-value problems of electrodynamics in the case of a circular waveguide with consideration for the reflections from the walls