This paper presents the results of the simulation component of the Poynting vector of the main mode of a three-layer-round waveguide. The middle layer is a LHM (Left-Handed-Medium) metamaterial with a negative refractive index. In a waveguide with LHM layer inversion of the radial component of the Poynting vector is observed.
We have studied the photoluminescence (PL) of AlGaAs/InGaAs/GaAs pHEMT heterostructures with donor-acceptor doping of AlGaAs barriers. We have found out that the application of additional p+doped AlGaAs layers leads to the appearance of the new bands in the PL spectra. These bands are identified as the transitions between 1) donor-acceptor pairs in the doped AlGaAs layers and 2) conduction subband - acceptor levels in the undoped InGaAs well.
Based on the known structural scheme of single-resonator microstrip directional traveling-wave filter the formation principles of multiresonator filters of this type are considered and substantiated.
The prototype of an ultra wideband (UWB) chaos generator of a microwave range is developed. This generator contains a nonlinear spin-wave transmission line, a multistage transistor amplifier with an output amplifier based on FET transistor and a microstrip pass-band filter. It is shown that in autonomous mode a UWB chaotic signal with central frequency of 3 GHz has an integral power level about 4 W in the frequency band that is greater than 30%. Such chaos generator has a high value of efficiency about 20%.
The results of modeling transformation of surface waves of a dielectric waveguide into spatial waves on different modifications of the double-row periodic structures are presented. Possibility of effective radiated power control of harmonics and selection of oscillations for the investigated structures is shown.
The optimum operating point of a transponder traveling wave tube was obtained. The dependences of satellite capacity on the return channel for 8-PSK and 16-PSK modulation are shown. It is determined that in case of one carrier it is better to operate at the saturation point, or close to it in case for a multicarrier. Optimal values of “input back-off” traveling wave parameter for a tube (for different cases it is in 0-4 dB range) are obtained.
The present paper describes a method to achieve sub-Hz frequency resolution in a microwave frequency synthesizer using commercially available digital PLL components. The key feature of this method is the spectral purity and frequency resolution comparable with the solutions based on direct digital synthesizer chips. The last ones are not used in the described method that allows obtaining the substantial economy in size, cost and power consumption of the system.
Experiments on local high-intensity electric current pulse effect on mechanical properties of silicon whiskers made it possible to reveal a novel type of electroplastic effect associated with the generation of dislocations. The procedure of electric current effect by single impulses on the siliconwhiskers of the having the highest specific strength from all investigated versions of shapes of a solid body is offered. The structure of crystals in an initial state and after the effect by single impulses of current of various density is investigated.
The results of research of frequency dependences of coefficients of reflection and transmission of radioabsorbing two-layer glass - Al2O3 structures with a thin film of aluminum are given. The resonance peak on the reflection characteristic with a maximum at -33 dB at a frequency of 13 GHz is found. The coefficients of absorption of electromagnetic radiation of studied two-layer structure in the range of frequencies of 6-18 GHz are calculated.
The present paper describes the design of the compact excitation device for TE01 mode of the circular waveguide based on antiphased dipoles. Numerical investigation of the developed device is conducted. As a result, it was found that the device has a transfer index at the frequency of 6.2 GHz, approximately -1 dB. Ways and methods of reducing in the transformation losses and widening of the frequency band are also described.
The main results of the IAP RAS activity at the powerful pulse THz gyrotrons are presented. The power about 200 kW at the frequency of 0.67 THz in single impulses with durations of 30 microseconds has been reached. This gyrotron is successfully used to initiate localized (characteristic size in the order about 1 mm) discharge in gases. The models describing the dynamics of discharge initiated by THz radiation are under development. New experimental facility for long pulse or CW gyrotrons in frequency band 0.28-0.52 THz has been build based on helium-free 10 T cryomagnet.
The present paper proposes a method of rarefied recursive coding of objects to be scanned in space in radar systems, which based on single-bit recursive tracking of Galois code scale. The developed method of rarefied reading allows reducing the technological requirements to the size of primary transformation elements. Rarefied reading of a single-bit scale allows simplifying the design and reducing the cost of mass production tracking systems of objects in space.
The problem of parallel algorithm development is considered. The main content of a solution presented is development of formal law of information formation on parallel algorithm structures. The way proposed of a solution search is characterized initially by a single view on algorithmic and architectural subsystems of a parallel computation system. The main peculiarity of the solution presented is synthesis of general description of sequential and parallel algorithms for digital signal processing operations. The basis for solution presented is developed methodology of data decomposition. The main peculiarities of methodology presented are its functional nature and the general approach to data decomposition of any dimension. The basic steps of methodology presented are considered. The methodology is the basis for development of the formal model of the parallel computation organization. The synthesis method of composition form for digital signal processing basic operations is considered.
The method of equivalent surface currents on the illuminated side of a multilayered antenna radome for calculation of reflection and transfer coefficients is suggested. The effects of antenna gain decreasing and the main lobe shifting are analyzed. The multilayered radome properties are calculated with tensor Green's functions.
Possibilities of basic functional parts parameter improvement of the industrial cesium atomic-beam tube, on which Russian global navigation satellite system GLONASS is based, are discussed.
The frequency dependence of the attenuation and reflection of electromagnetic radiation of wet fibrous materials based on organic structures in the range of 8 - 12 GHz has been investigated. The possibility of extending the temperature range of operation of the test materials to 180 °C with minimal loss of the liquid component and maintaining high shielding performance was considered. Practical recommendations for the creation of shielding structures to protect objects from stray electromagnetic radiation are proposed.
Implementation of the proposed new technical solutions will provide delivery for 2,000 users multimedia services data signals with up to 12Mbit/s speed for each subscriber.
The present paper concerns the possibility to use the microwave method to localize tumours by means of the combined horn antennas with dielectric resonator. Application of metal plates around the dielectric resonator allows adjusting the radiation pattern of antennas and VSWR. VSWR, S-parameters, chart orientation and interaction with multilayer dielectrics are simulated.
A unique geographical and chronological map of telecommunications technology in the world that demonstrates how, where and when were created the technologies that have influenced the development of the whole sphere of communications. The fundamental principles underlying the construction of maps of the history of telecommunications are presented.
