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The algorithm for the calculation of the resonant characteristics of an impedance monopole placed on ideally conducting infinite screen is developed with using the asymptotic expressions for a current and an input impedance of the thin impedance wire dipoles with electric length 0.4 < 21 / λ< 0.6 in the free space. On the basis of the numerical calculations the detailed analysis of resonant...
A numerical analytic problem solution of a diffraction radiation of a narrow rectilinear slot into space over an infinite impedance screen is presented. An asymptotic solution for the magnetic current in the slot was obtained by a generalized method of induced magnetomotive forces (MMF) applying the Green's functions for the space above the impedance plane. Influence of the screen impedance coating...
On the base of the uniform geometric diffraction theory method, using the asymptotical expression for a current of an impedance wire dipole located over a perfectly conducting plane, the fast active algorithms and programs are developed for computations of the directional and polarization characteristics of radiation produced by two synphasely excited crossed dipoles placed in parallel to a square...
A mathematical model of a E-plane T-junction of rectangular waveguides with three-element monopole-slot coupling structure is developed based on an approximate analytical solution of an equation system for currents by a generalized method of induced electro-magneto-motive forces (EMMF). The characteristic feature of the T-junction model is that it simultaneously takes into account two factors: the...
A radiation field of a radially oriented dipole located on a sphere was studied using an electric Green's function for the space outside of an impedance sphere. The directivity of the spherical antenna in wave zone was determined depending upon variations of the sphere diffraction radius and reactive impedance magnitudes.
The 3D vector problem of diffraction of the field of the system of synphasely excited crossed half-wave wire dipoles of similar geometrical sizes, but with different surface impedances, and located parallel to the perfectly conducting rectangular screen, has been solved. On the base of the uniform geometric diffraction theory method with using the asymptotical expression for a current of an impedance...
The necessary conditions which provide the circularly polarized radiation with maximum directive gain for the in-phase crossed impedance wire dipoles system located over a perfectly conducting square screen have been investigated in the normal direction to the screen. On the base of the uniform geometric diffraction theory method with using the asymptotical expression for a current of an impedance...
Radiation fields of a radially oriented dipole located on a metal sphere coated with a thin layer of absorbing metamaterial are investigated. Numerical simulations were performed by using the electric Green's function for the space outside of an impedance sphere. An impedance of the metamaterial layer required to minimize the influence of the spherical scatterer with resonant dimensions upon the directivity...
The 3D radiation patterns of the tilted impedance wire dipole located over a perfectly conducting infinitely thin finite size screen are investigated by the uniform geometric diffraction theory method. The technique is developed for definition of a slope angle of the wire dipole taking into account the diffraction effects on the screen edges at which the circularly polarized wave in the set directions...
The problem of electromagnetic wave excitation by a vibrators system with variable distributed surface impedance located in free space is solved by the generalized method of induced electromotive forces (EMF). The characteristics of three-element and multi-element Yagi-Uda antennas with variable impedance vibrators are calculated.
For a radiating system consisting of a resonant half-wave impedance oblique wire dipole and a rectangular perfectly conducting screen the conditions guaranteeing formation of a circularly polarized wave with extremely achievable field amplitude in the set directions of the main observation planes are investigated. Computation of the far field components is based on the asymptotic solution of 3D vector...
The problem of electromagnetic waves radiation by a longitudinal slot in the broad wall of a rectangular waveguide is solved. The slot is radiating into half space above a perfectly conducting plane in the presence of two passive vibrators (monopoles) having variable distributed surface impedance in the space above the plane.
A mathematical model of a radiating structure consisting of an narrow arc slot cut in a perfectly conducting sphere and two radially oriented impedance monopoles located on the sphere. Formulary relations for radiation fields of the spherical antenna at an arbitrary point of observation were obtained based on external electrodynamic problem solution by the generalized method of induced electro-magneto-motive...
The 3D vector problem of diffraction of the field of a thin impedance vibrator located over an ideally conducting infinitely thin rectangular screen is solved. The vibrator may have surface impedance distributed over its length. Asymptotic expressions for the current on a horizontal impedance vibrator placed over an infinite plane, obtained by averaging method were used. Full radiation fields in all...
Electromagnetic characteristics of the E-plane T-junction for two rectangular waveguides using resonant coupling between the waveguide sections are investigated. The problem of coupling between infinite and semi-infinite rectangular waveguides through a resonant slot in the end-wall of the semi-infinite waveguide in the presence of resonant monopole is solved in a strict electrodynamic formulation...
The problem of electromagnetic waves radiation by a spherical antenna is solved using a rigorous self-consistent formulation. The antenna consists of a perfectly conducting sphere and a narrow slot cut in an impedance end-wall of a semi-infinite rectangular waveguide excited by a fundamental wave H10. An asymptotic solution of the integral equation for a magnetic current in the slot aperture was found...
A problem of electromagnetic waves scattering and radiation by a structure consisting of two asymmetrical vibrators (monopoles) with variable surface impedance allocated in a rectangular waveguide and a narrow transverse slot cut in a broad wall of the waveguide is solved by the generalized method of induced electro-magneto-motive forces (EMMF). Wavelength dependencies of energy characteristics of...
A problem of electromagnetic waves excitation by a structure, consisting of a narrow transverse slot in a broad wall of a rectangular waveguide and a vibrator with variable surface impedance, located inside the waveguide, is solved by the generalized method of induced electro-magneto-motive forces. Conditions, necessary for achievement of maximal slot radiation coefficient are defined. Calculated...
The problem concerning the creation of the radiation field with circular polarization in the certain direction by turnstile antenna, consisting of the impedance vibrators, excited cophasedly, has been solved on the basis of the solution of the problem about radiation of the thin impedance vibrator over the perfectly conducting plane. The length and the value of the surface impedance of one vibrator...
The problem about radiation of electromagnetic waves by the thin vibrator with the symmetrical and antisymmetrical components of the surface impedance relative to its centre, where the point source of excitation is located, has been solved by the generalized method of induced electromotive forces. The analytical expressions, obtained in a closed form, allow to obtain the current distribution along...
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