A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura Str., Kharkiv 61085, Ukraine
Transverse Doppler Effect-Based Frequency Shifter
A block diagram of a quasioptical (QO) frequency shifter (FS) is proposed, in which a transverse Doppler effect has been originally employed. This block diagram provides for a continuous frequency shift much as polarization frequency shifters do. The physical processes that occur in the FS under consideration have been analyzed. It is found that the mirror moving transversely to the incident radiation along with the known force of pressure is acted upon by the lateral force directed towards the mirror motion. The FS block diagram ensures a 4-fold return of the QO beam from the mirror and eliminates the influence of parasitic mirror vibrations on the transmitted radiation phase. The application of the proposed FS may be found to be beneficial in homodyne measuring systems with frequencies ranging from THz and higher up to the optical ones.
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura Str., Kharkiv 61085, Ukraine
Microstrip Grating Placed in Open Resonator
The possibility of excitation of the fundamental mode in the semi-symmetrical open resonator(OR) by using the four-element microstrip grating (MG) is considered. The characteristics of MG are calculated on the basis of the spectral method for the frequency of 10 GHz. The experimental dependencies of the loaded Q-factor and resonant transmission coefficient via the distance between the mirrors of the OR are provided if the latter is excited by the MG and the slot. The prospects for application of MG to develope an active high-Q quasi-optical source of oscillations within the mm-band is demonstrated.
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura Str., Kharkiv 61085, Ukraine
Axially-Symmetric Eigen Modes of Electric-Type in the Open Resonator with Spherical Mirrors
A rigorous mathematical model describing axially-symmetric eigen oscillations of electric-type in open resonators with spherical mirrors has been developed. Under the assumption on the existence of a spectrum of complex eigen frequencies of open resonators, it has been proved that the spectrum is discrete, finite-multiple, and with the only accumulation point on infinity. A theoretical analysis of spectral characteristics of an open resonator has been carried out for the case when the wavelength is comparable with the resonator dimensions. The validity limit of some well-known asymptotic models of open resonators has been specified.
A. Usikov Institute of Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura Str., Kharkiv 61085, Ukraine
Ground-Penetrating Radar Data Preprocessing
An algorithm for dynamic selection of clutter components in a signal of a videopulse ground-penetrating radar (GPR) is proposed. Clutter-resistant estimates of radio contracts are made. The robustness of these estimates has been achieved by optimal data weighting. An algorithm of suppressing anomalous bursts in a signal is proposed. The ways to subsequently elaborate the techniques for preprocessing these types of signals are discussed.
National Aerospace University
1, Cosmonaut Komarov Avenue, 03058 Kyiv, Ukraine
Detection of Potential Aircraft Icing Zones by Remote Sensing of Meteorological Objects
The results of mathematic simulation of remote sensing of the meteorological objects are shown. The values of main polarimetric variables are calculated. The comparison of calculated values with the results of practical measurements is performed. Potential icing zones detection algorithm is recommended.
Evaluation of the Effectiveness of an Optimal Filter for Detection of an Object by the Method of Nonlinear Radar Sensing
National Polytechnical Institute of Mexico, Mexico
Performance of a Communication System with Information Feedback by Using an Entire Systematic Code Scheme and a Divided Code Scheme
The performance of the communication systems with information feedback driven by white Gaussian noise is analyzed. We are considering two cases of performance of these kinds of communication systems: when they are using code schemes on both channels and when they used a divided code scheme. On the basis of general expressions for these communication systems, we determine the main statistic parameters of some common code schemes. Finally, we compare the performance of this two methods graphically.
National Polytechnic Institute of Mexico, Mexico
Detection of Voiced Speech Segments of Esophageal Speakers
This work presents the design and implementation of an esophageal speech analysis system, suitable for voiced speech segments extraction. This paper provides the mathematical fundaments of the voiced speech segments analysis algorithms based on the formant extraction method. Simulation results are provided together with the implementation of the system using real time processing platform based in a digital signal processor TMS320C5416 of Texas Instruments.
Analysis of Models for Monitoring of the Technical State and Diagnosis of Electronics and Computer Technologies
Detection of Periodic Pulse Sequences in an Additive Mixture with Chaotic Pulse Interference
