Vol 17, No 4 (2014)
- Year: 2014
- Articles: 13
- URL: https://journals.ssau.ru/pwp/issue/view/387
Articles
Light squeezing it two-atom Jaynes - Cummings model with intensity-dependent atom-field coupling
Abstract
The features of light squeezing for two two-level atom interacting with a coherent field in finite-Q cavity taking into account dependence of atom-field coupling from intensity of a field are explored. The computer modeling of the squeezing parameter revealed that the maximum degree of squeezing for considered model considerably surpasses corresponding quantity for one-photon case.
Quantum limitations of distant radiating objects detection
Abstract
Weak electromagnetic signals from sufficiently distant sources reveal quantum properties. The latter ones result that detection of the sources becomes probabilistic. The analysis of received quanta intensity spectra permits to evaluate the limit (by finite exposure) of distance of detection of definite class heavenly body. By the quantum interpretation of the background radiation experimental results the maximum frequency temperature (the Wien’s law) decreases in 1.77 times. In such a case the background radiation absolute temperature would to be changed from 2.73 to 4.83 degrees.
Mathematical modeling of diffraction of tem-wave on the periodic 2D structures of graphene micro-ribbons with finite length at terahertz frequency range
Abstract
The mathematical simulation of diffraction of TEM-wave on the periodic 2D structures of graphene micro-ribbons with finite length is performed using the computational algorithm developed by projection method for the normal incident TEM-wave at terahertz frequency range.The results of electrodynamic calculation of the transmission coefficient for the TEM mode through the graphene micro- and nanoribbons with finite length depending on the frequency were obtained for different values of chemical potential (the external electric field) for different sizes of ribbons and the periodicity of the array.
Weight vector jitter influence on statistical characteristics of adaptive antenna array with nonlinear function in correlation feedback, tuning on LMS algorithm with quadratic constraint
Abstract
In the article it is researched influence of weight vector jitter on the statistical characteristics of adaptive antenna array with nonlinear function in correlation feedback, tuning on LMS algorithm with quadratic constraint. It is shown, that weight vector jitter leads to distortions of adaptive antenna array statistical characteristic (correlation function of output signal, output power, correlation matrix of weight vector jitter).
The integral model of fractional Thomson self-oscillator
Abstract
A numerical model of self-oscillating system with an integral equation of motion is designed. The results of modeling transient process of self-oscillations are presented. There compare with the analytical results are obtained in the quasi-harmonic approximation.
Multi-alternative identification of objects with an assessment maximum likelihood of same parameters
Abstract
With use of criterion of a minimum of average risk and estimates of maximum likelihood of same parameters synthesis of algorithm of multi-alternative identification of objects by in common functioning monitors in the conditions of aprioristic uncertainty of signs of identification is executed. Statistical characteristics of efficiency of an identification of the purposes by results of independent measurements of their coordinates are investigated.
Method of the coordination of the antenna on two it is considerable the spaced apart frequencies
Abstract
In article the method of the coordination of the antenna on two considerably spaced apart frequencies is considered. Edge conditions of usage of the given method are defined and examples of calculation of lengths of the matching transformer and idling loops are resulted.
Ranges of microwave fluctuations in concerning the magnetized films ferroshpinelya
Abstract
Features of ranges of absorption in concerning the magnetized single-crystal films ferroshpinely, the chemical transport reactions received by a method are considered. Existence of range of frequencies of superficial and volume magnetostatic fashions is established. The cumulative observed effect for films ferroshpinely are ostsillyation of attenuation of absorption of magnetostatic fluctuations with frequency change. Dependence of a picture of ostsillyation of attenuation on fixing parameter спинов and sizes of a constant of superficial anisotropy is found. Features in attenuation are a characteristic sign of resonant interaction of dipolar and exchange waves. Wave numbers, fixing parameters спинов, and constants of a non-uniform exchange are calculated.
About the prospects of silicon field-effect transistor microwave for running a temperature of 450-700 K
Abstract
Proposed a model of silicon MOS transistor designed for pulsed operation up to T = 550 K. The main feature of the model is an abnormally high level of doping drain region. The estimation of the rate of degradation of the operating parameters of the device. It is shown that the uptime of the device when the channel length L ~ 600 nm and depth of its location beneath the work surface x_10 ≥ 500 nm is not less than 1.5 years. Calculations of the degradation performed for T = (600-700) K may be useful in the design of high-temperature devices based on wide bandgap semiconductors.
Functional single-chip light-to-frequency converter based on high-resistivity
Abstract
The prototype of single-chip light-to-frequency converter is described. This converter is a mesa-planar photoresistor structure based on high-resistivity gallium arsenide with an N-shaped current-voltage characteristic. The converter functionality and utility for optoelectronics are showed. The main characteristics are indicated. The advantages and limitations of the proposed converter under the present analogs are analyzed.
Analysis of annihilation positron and electron and additional opportunities of the positron-emission tomography
Abstract
The reasons of angular photon distribution occurrence at electron-positron annihilation are considered. It is shown, that angular photon distribution is consequence of Doppler’s effect in the reference frame of the electron and positron mass center. In the reference frame bound with moving electron the angular photon distribution is absent. But it is replaced by the Doppler’s shift of photons frequencies. The received results are applied to the analysis of a positron-emission tomograph work.
Calculating the self-capacitance of planar structural elements of the spacecraft
Abstract
The paper presents a methodology for calculating distribution of potentials based on the triangulation method of plane approximation, surface method and analytical determination of the matrix elements of Coulomb interaction. The results obtained demonstrate good agreement with the experiments on the electrization process in small spacecraft «AIST».