Complex directional antenna consists of separate near-omnidirectional antennas (radiating elements) positioned in the space and driven by high-frequency …

Admittances of antenna array waveguide radiators on a wedge: the results of numerical and experimental studies

The quantitative analysis of physical processes that occur during the excitation of planar and rectangular waveguides with an infinite flange, with a bending flange and an array of planar and rectangular waveguide radiators on an infinite plane and on an infinite wedge has been carried out.
The quantitative analysis of physical processes that occur during the excitation of planar and rectangular waveguides with an infinite flange, with a bending flange and an array of planar and rectangular waveguide...

Admittances of antenna array waveguide radiators on a wedge: deducing the main relations

Equations for the “irregular” and “regular” transfer admittance of the waveguide radiators of an antenna array located on a side of an infinite ideally conductive wedge is deduced.
Equations for the “irregular” and “regular” transfer admittance of the waveguide radiators of an antenna array located on a side of an infinite ideally conductive ...

Patch antennas with artificial dielectrics substrates

Approach for the analysis and Q–factor estimates of patch antennas with artificial dielectrics substrates for decimeter and larger wavelengths have been considered. Parameters range not leading to significant normal dispersion have been estimated and treated. Also shown that a frame of periodic system of capacitive ...

Method of antenna isolation with the help of periodic structures

A short digest of the methods that are applied for antennae decoupling decreasing in the presence of an underlying surface is given. The computation results of weakly directional antennae decoupling with the help of periodic ribbed and strip structures located on an underlying surface along a coupling ...

The article presents a critical analysis of possible uses of metamaterials to improve operation of antenna devices and points out directions of necessary studies in the field of metamaterials.
Radio engineering and electronics

Characteristics of antennas with spherical dielectric lenses

... spherically symmetric structure, excited by a generalized Huygens, are considered. It is shown that the method is based on reducting the source vector problem to two scalar problems for Debye potentials. The amplifying ration and directional diagrams of antennas based on spherical dielectric lenses are researched and experimental estimation of numerical results is given.
Radio engineering and electronics

Modeling spherical lens antennas taking into account radiator characteristics

A numerical algorithm for solving the problem of diffraction of electromagnetic waves on a multi-layer dielectric lossy sphere when amplitude-phase distribution of the exciting field is arbitrary is developed. The algorithm is based on representing the field on the source surface as an aggregate of the electrical and magnetic dipoles and reducting the vector problem to two scalar ones for the case of a point source. The results of calculating the directional diagrams and amplifying ratio are compared...

Researching and optimizing the characteristics of lens antennas based of double-layer dielectric sphere

The numerical research and optimizing the characteristics of antennas based of double-layer spherical dielectric lenses, taking into account aberration effects, lens refelections, dielectric losses, radiator directivity diagrams and transition layers are carried out. As an optimization criterion, the maximum value ...

The equation for the maximum working bank and coordination level, dependent on the electrical size of some ideal according to the Chu and Harrington criteria antenna is reduced. The characteristics of coordination is assumed to be rectangular and the contact ration can be arbitrary. The received equation expresses the limit of the Chu–Harrington limit for the relative line, coordination level and electrical ...

About the measurement inaccuracies of dispersion diagrams in Fresnel zone

The measurement inaccuracies of dispersion diagrams of an arbitrary body in Fresnel zone that arise because of the finite distance between the body and the radiating antenna, and the body and the receiving antenna, as well as the directivity of the antennas are considered. The measurement inaccuracies of dispersion diagrams in the near zone of collimator in case when the boundary wave effect can be ignored are studied....

About the inaccuracy of measuring the directivity factor and directional diagrams of antennas at a short distance

The first three terms of the asymptotic decomposition of the transfer ration between two antennas with arbitrary directional diagrams and polarization types are obtained. The formulas for the distance that can be used to measure primary and lateral radiation with the given inaccuracy are derived.
Radio engineering and electronics

About computing the characteristics of radiation of pyramidal horn antennas

... characteristics of radiation of sharp pyramidal horns using aperture integrating when determining the field in a plane discontinuity point using approximating functions will be carried out. The calculation results are compared to the previous ones.
Antennas

Computing the electrodynamical characteristics of horn antennas

... electrodynamics for horn radiators with perfectly conducting plane flange, powered by cylindrical waveguides, is considered. The results of numerical calculations for the pyramidal and sectorial horns powered by the rectangular waveguide are provided.
Antennas

Scattering of electromagnetic waves by mirror antennas

Scattering of a plane wave by mirror antennas with vibrating radiators is considered. The Fourier coefficients of the vector function equal to the current density on the mirror metal and the tangent component of the electrical vector on the geometric surface, complementing the surface of ...

The limit value of the directivity factor of the antenna located in a lossy medium

It is shown that the directivity factor of the antenna located in a lossy medium is limited and its maximum value is finite.
Radio engineering and electronics

About minimizing the integral diameter of dispersion of aperture antennas

The formula that relates the integral diameter of the distance to the effective absorbing surface of the aperture receiving antenna is derived and using this formula, the conditions of minimizing the diameter and its value are found.
Radio engineering and electronics

Lens antenna based on a homogenous dielectric sphere: characteristics and potentiality

Researche and optimization of characteristics of lens antennas based on a homogenous dielectric sphere, taking into account the aberration effects, reflections, dielectric losses, radiator directional diagrams, matching layers and technological tolerance are carried out; the relation of antenna characteristics ...

Restoring the antenna directional diagram using the Fresnel zone measurements on a measurement stand in a far zone

The method of determining the antenna directional diagram using the amplitude and phase measurements in the Fresnel zone is considered; the mathematical rationale of the method is given along with the results of computer and experimental modeling and the samples of using when measuring ...

Scattering of electromagnetic waves by antennas (overview)

This is given the overview of the known approximate methods of calculating the scattering of electromagnetic waves by antennas, including calculating the integral and differential surfaces of dispersion; simple formulas for estimating these values are given. In addition, some results that belong to the authors of the work are stated.
Radio engineering and electronics

About the maximum power that is drown by the antenna in a lossy medium

It is proved that when the primary incident field in a lossy medium is fixed, the power drawn by the antenna is finite. It is not necessary to limit the direction of the receiving antenna, unlike the case of a lossless medium when this is required to get a finite maximum.
The formulas for deriving the maximum received power and the optimal distribution ...

About the power, drawn by the receiving antenna from the incident field

Are received various variants of formulas for computing the power, received by the receiver, which take into account the discrepancy between the ends of the feeder path, when the form of the incident wave is arbitrary. In the special case where the receiver is completely concordant with the path, one of them grades into the Burstein-Kinber formula.
For different additional conditions, the high bound of the received power is determined and the optimal distributions of the field that make this power...