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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...
The antenna array of four arc monopoles which are located parallel to the surface of a perfectly conducting or impedance sphere is considered. The influences of the phase of excitation of a monopole, the distance to the sphere surface, and sphere radius and its surface impedance on the directivity of the radiator are considered. It is shown that the radiation pattern of the antenna for antiphase excitation...
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.
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 antenna array of two arc monopoles which are located parallel to the surface of a perfectly conducting or impedance sphere is considered. The influences of the phase of excitation of a monopole, the distance to the sphere surface, and sphere radius and its surface impedance on the directivity of the radiator are considered. It is shown that the radiation pattern of the antenna for antiphase excitation...
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 energy characteristics of the junction consisting of two perpendicular crossed infinite rectangular waveguides coupling through a narrow slot are studied. A transverse slot cut in the wide wall of the first waveguide coincides with the similar slot orientated along a longitudinal axis of the second waveguide. A dielectric insert is allocated in the coupling slot of the first waveguide. The geometry...
Multiparametric energy characteristics of a T-shaped waveguide junction with a dielectric insert in a coupling slot area were numerically studied in the range of single-mode operation of the main rectangular waveguide based on the developed mathematical model. The end-wall of the side waveguide where the coupling slot were cut is supposed to be impedance. It was shown that the dielectric insert can...
For a resonant impedance wire dipole that is inclined at the angle over a square 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 depending on the screen sizes are investigated. The asymptotic solution of the 3D diffraction problem of the field of an arbitrarily...
The problem of coupling between infinite and semiinfinite rectangular waveguides with different cross-sectional dimensions through a resonant slot in the end wall of the semiinfinite waveguide in the presence of resonant monopole is solved in a strict electrodynamic formulation. The monopole with variable surface impedance is placed parallel to the narrow walls at an arbitrary position inside the...
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...
Multiparametric energy characteristics of a waveguide junction in the range of single-mode operation of a main rectangular waveguide containing a dielectric insert in the slot area were studied. The dielectric insert was used as a control element for the power division between the output shoulders of the waveguide joint.
An algorithm of calculation of the directivity, energy, and polarization radiation characteristics of an arbitrarily oriented thin impedance vibrator located above a rectangular screen is developed on the basis of the asymptotic solution to the 3D problem of diffraction of the field of the electric vibrator by a perfectly conducting rectangular screen. The asymptotic expressions for the current of...
The characteristics of the radiation field of the monopoles on perfectly conducting spherical scatterer — spherical antennas are discussed in the paper. To solve this problem the authors used the solution for the radiation field of a single monopole excited at the point of contact with the sphere. Monopoles are located in the equatorial plane and driven the individual voltage sources. The dependences...
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...
The problem of electromagnetic waves radiation into a space outside a perfectly conducting sphere through a narrow slot, cut in an end-wall of a semi-infinite rectangular waveguide, excited by a fundamental wave of H10 type is solved using a rigorous self-consistent formulation. The starting point for the analysis is the one-dimensional integral equation for the equivalent magnetic current in the...
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