Izvestiya of Saratov University.
ISSN 1817-3020 (Print)
ISSN 2542-193X (Online)

Радиофизика, электроника, акустика

Negative Dispersion, Refraction and Backward Polaritons: Impedance Approach

Background and Objectives: The dispersion equations of surface plasmon-polaritons are derived for the general case of layered dissipative structures. The waves are classified as gliding with energy flow into structure from vacuum and leakage ones. The dispersion equations and conditions for the existence of slow and fast gliding and leaky waves, as well as forward and backward waves are considered.

Simulation of a Sub-THz Traveling Wave Tube with Multiple Sheet Electron Beam

Background and Objectives: Many applications, such as highdata-rate wireless communications, spectroscopy, high-resolution radar, biomedical imaging, security, etc. require compact highpower sources of sub-THz radiation. Traveling wave tube (TWT) amplifiers are the most promising candidates for such sources combining 10–100 W power and wide b andwidth. Here we present the results of design and simulation of a 0.2 THz TWT with a grating slow-wave structure (SWS) and electron-optical system (EOS) with three elliptic-sha ped beams.

Spiral Wave Patterns in Two-Layer 2D Lattices of Nonlocally Coupled Discrete Oscillators. Synchronization of Spiral Wave Chimeras

The paper describes the spatio-temporal dynamics of a lattice that is given by a 2D N × N network of nonlocally coupled Nekorkin maps which model neuronal activity. The network behavior is studied for periodic and no-flux boundary conditions. It is shown that for certain values of the coupling parameters, rotating spiral waves and spiral wave chimeras can be observed in the considered lattice. We analyze and compare statistical and dynamical characteristics of the local oscillators from coherence and incoherence clusters of a spiral wave chimera.

The Method of Visualization of Spatially Inhomogeneous Acousic Fields from Micro-Objects on the Basis of Acousto-Optic Interaction in the System with Double Fourier Transform

Background and Objectives: The method of acousto-optic visualization based on a double Fourier transform is presented. In a hybrid acousto-optic processor, the double Fourier transform is realized in the process of converting an acoustic signal from an object by an acoustic lens formed by the conjugate spherical surfaces of two crystals, and the subsequent processing of light diffracted in a photoelastic medium by an optical collecting lens.