Anatoliy A. Kirilenko

Research on orotron oscillator with dispersive open resonant system

Theoretical and experimental results of an investigation into a new resonant system have been obtained. This system is named the sphere-corner-echelette open resonator (SCEOR) due to the employment of a mirror that was formed by two echelettes at the angles of 45° to the resonator axis. It turns ont that this resonator is excited on the specific modes not unique to others oscillating systems.There are presented the results of the experimental research of the orotron oscillator with the SCEOR. The spectrum of this device contains only the fundamental modes such as theT E M006,T E M007,T E M008. The efficiency of the orotron is improved, when all other factors are the same the orotron with a much used sphere-cylindrical open resonator.

Abnormal propagation of EMW through below cutoff holes and intrinsic oscillations of waveguide objects and periodic structures

Spectral theory is used to explain the effect of propagation through below cutoff holes. Intrinsic oscillations of the corresponding waveguide and periodic open resonators are studied. Their influence on the frequency characteristic is demonstrated for various structures: from waveguide to array.

Nonsymmetrical H-plane corners for TE/sub 10/-TE/sub q0/-mode conversion in rectangular waveguides

Compact high-efficient TE10-TEq0-mode converters based on truncated H-plane angular junctions of single-mode and overmoded rectangular waveguides are designed and investigated. The comparison analysis of converters without and with an inductive iris in the input port is carried out. Iris-free converters are broader in bandwidth, while iris-matched ones provide a better purity and higher conversion efficiency. It is found that the same configuration can provide a high-efficient conversion to different TEq0 modes in different parts of the frequency operation range. Two interpretations of the conversion physical mechanism are discussed

Polarization Response Manipulation for Compound Circular Hole Fishnet Metamaterial

Two compound circular hole screens, which possess rotation symmetry and are conjugately stacked in such a way that the whole structure has <inline-formula><tex-math notation=LaTeX>

Rectangular waveguide section with a pair of antipodal posts: Spectral characteristics

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Beam-Forming Capabilities of Waveguide Feeds Assisted by Corrugated Flanges

</tex-math></inline-formula> dihedral symmetry, are considered to rotate polarization plane of a normally incident wave. The eigenmodes responsible for the polarization plane rotation are analytically investigated on the base of the representation theory of groups and illustrated by numerical results.

Spectral properties of a rectangular waveguide section with a pair of two transversal ridges

Scattering characteristics of a waveguide section with a pair of antipodal posts are studied. The section is formed by two short rectangular inserts arranged in antipodal position in a cross section of a rectangular waveguide. Influence of changing the posts dimensions on the section frequency response is numerically investigated. A pole generation mechanism is examined within the concept of the spectral theory of open waveguide resonators. Attenuation pole generation is demonstrated over the single-mode range and in a wide multi-mode range. It is shown that “spectral” estimations of the pole frequency and bandwidth are more precise than ones obtained within the ordinary `modal approach. High-accuracy estimation is demonstrated in a wide frequency range.

Polarization Plane Rotation by Arbitrary Angle Using

The physical mechanisms behind the formation of shaped-beam radiation patterns by flat horns (i.e., open ended waveguide feeds with finite-size corrugated flanges) are studied in a rigorous manner using the singular integral equation (SIE) approach. The problem is considered for TM polarization in the two-dimensional (2-D) formulation. First, dispersion curves of periodic grating are presented and used to analyze the modes supported by the waveguide flanges. This includes the surface wave, stopband, and leaky-wave regimes. The modes corresponding to the poles on the bottom “nonphysical” Riemann sheets are also considered. Finally, various types of radiation patterns produced by flat horns with gratings operating in different regimes are illustrated with an emphasis on generating sectoral beams being of interest for many practical applications. The results are validated via comparison with full-wave three-dimensional (3-D) analysis.

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Short metal ridges in a rectangular waveguide appeared to be promising units for different microwave filters providing complicated frequency response. In particular, a waveguide containing two rectangular even (or uneven) ridges was used [1] to provide high-quality resonant reflection of the incident mode. A pair of equal height posts in a rectangular waveguide was used lately [2] in order to design a bandpass filter generating an improved response with additional attenuation poles. A quasi-elliptic filter based on a pair equal height posts was reported recently [3]. Off-centered single post and slant single ridge were used successfully in a modern filter design as well [4, 5]. Nevertheless the physical nature of the phenomenon of an attenuation pole generation provided by all the mentioned resonant sections remained unrevealed. Here we use the spectral theory of open waveguide resonators [6-8] to solve this problem. Within the frames of the spectral theory a waveguide unit is considered as open waveguide resonator loaded by semi-infinite guides. Different resonant regimes are interpreted as a response on the excitation of the natural oscillations of the resonator. Similarly to [9], we expect that understanding the physical nature of the resonant phenomena makes their conditions and limitations more clear.

Symmetrical Structures

A compact waveguide polarization rotator, able to turn the polarization plane by an arbitrary angle, is proposed. Its operational principle is based on a strong electromagnetic coupling between two conjugated quadruple-slot planar-chiral irises in a square waveguide by the below cutoff modes. The physical interpretation for the observed phenomenon is provided based on the analysis of the eigenoscillations of such a D4 symmetrical object considered as an open waveguide resonator. It is demonstrated that there exist two perfect matching points controlled by the iris geometry and width of the narrow gap between two planar chiral components. The reported unit has a bandwidth of several percent with return loss better than 20-30 dB. The conclusions of this work are fully applicable to double-periodical two-layer screens or metasurfaces having such square cells.