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The electromagnetic fields created by the arc slot cut in the coaxial line shield have been found in the present work for any distances from radiator. Kirchhofes method has been applied for coaxial-slot antenna near-field determining. Electromagnetic near-field distributions have been explored for different values of coaxial-slot antenna parameters on a large range of wavelengths. Field diffraction...
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...
This communication is aimed at problems associated with a functional neutralization of on-board radioelectronics systems of small-size unmanned aerial vehicles by high-power out-of-band radiation in microwave band.
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 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...
Antenna devices are the integral part of the modern telecommunication systems. Radiating cables in the form of slot array cut in a coaxial cable shield are widely used as the antenna devices working in tunnels, mines, skyscrapers, on moving vehicles and other structures with a high degree of a shielding. Significant advantages of such systems include: a simplicity of radiator excitation, broad operating...
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 small-sized radiators (receivers) of electromagnetic waves on the base of the system of six equidistant radial monopoles in the equatorial plane of the conducting sphere are considered. It is shown that for the antenna the various directional patterns by switching phases of voltage sources only for two monopoles can be realized. The considered radiators can be used as a small-sized sensors and...
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...
Scattering parameters of a slotted diaphragm in a rectangular waveguide are studied. The transverse slot in the diaphragm is partially filled with dielectric. The mathematical model includes accounting several spatial harmonics for description the electrical field in the slot. Resonance wavelength dependence on geometrical structure and electrical parameters of the insert in the slot is revealed....
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