This article describes new method of correction of magnetic field MPFS TWT. The method allows controlling the magnetic induction instead of the current coefficient of retarding system. This approach reduces time and increases quality of correction. The key point of the method is in controlling of magnetic field on the assembly stage. The iteration algorithm of correction was developed. It is necessary to remember the coordination of the point, which need to be corrected. After measurement the researcher will know the result of influence of correction, which he or she applies to the system. In such way all magnetic system need to be controlled. This article represents the result of this approach and shows its benefits and lacks.

Keywords: periodic magnetic focusing system, a traveling wave tube, the magnetic field, the electron beam

Application features of dynamic memory devices based on binary fiber-optic structures are researched in optimal filters of sequence of pulse signals.
The possibility of significant improvement of signal-to-noise ratio in optimal filters of sequence of pulse signals using non-recirculating binary structures compared to recirculators is proved.
Application of the technical solution based on the method of enhancing identity copies in binary fiber-optic structures allows to achieves the gain in signal-to-noise ratio of about 37 dB for 4096 copies processed, this corresponds to the gain of 22 dB compared to typical recirculator.

Keywords: binary fiber-optic structure, optimal filter, pulse sequence, signal-to-noise ratio

The paper describes the method for determining the position of the contact wire of electrified railways using microwaves. The method is based on the triangulation system of two georadars and allows to determine a contact wire zigzag and height from the rail head. The proposed method is all-weather with the possibility of continuous monitoring of the overhead contact wire in plan and profile with the opportunity to automate the processing and signaling abnormalities.

Keywords: railroad contact line, contact wire location, GPR, automatic control systems

Based solutions of avalanche transit diode amplifier for under the influence of microwave amplitude- modulated optical signal at the p-n junction diode is determined by the response of the amplifier , while a detector device characteristic. We investigate the influence of numerous system parameters on product detection.

Keywords: frequency response; avalanche diode; amplifier; detector; Microwave amplitude modulated optical vibration .

In the article a double-gap cavity with anti-phase excitation that has wide application in designs of floating-drift klystrons is considered. One of the ways of reduction of time during machine design of klystron’s cavity is using of the simple analytical expression, allowing to determine the main klystron electrodynamic parameters with a sufficient accuracy for practice. In the article we presented the results of physical and mathematical modeling of the double-gap cavity, the corrected mathematical models were introduced that can be utilized in programs of a prompt optimization of klystron's type devices. The technique of creation of approximate mathematical model in this case was reduced to definition of basic analytical function, and the subsequent approximation between experimental and calculated data by means of a method of planned experiment. In presented work the analysis of adequacy was carry out. Analysis revealed inaccuracy of a resonance frequency of an anti-phase type in chosen ranges of change of influencing factors doesn’t exceed 1%, characteristic impedance- 5%. The received analytical ratios allow carrying out quickly calculation of parameters of the cavity, without labor-consuming and expensive experiments and calculations.

Keywords: double-gap cavity, electrodynamic parameters, mathematical simulation, resonance frequency, characteristic impedance, method of planned experiment

For miniaturized vacuum klystron type devices utilization of a double- gap strip-line cavity with suspended ceramic substrate is very promising. 
The two-mode operating mode of such cavities practically isn't studied enough; so there is the great scientific and practical interest for research of electrodynamic characteristics of cavities during multi-mode operation that correspond to simultaneous excitement of anti-phase and co-phase modes in a double gap.  
In this article results of the 3-D numerical modeling by means of the Ansoft HFSS code are presented, and also the experimental results of the electrodynamic properties of the half-wave double- gap cavity with the suspended ceramic substrate are submitted. Optimum parameters of this design, allowing to carry out simultaneous excitement at multiple frequencies with frequency rate (K=2) are determined.
In such cavity high values of unloaded Q factors isn’t need because dielectric losses and conductor losses can be compensated at the expense of  the negative electronic conductivity that brought by modulated electronic beam. The operating mode with frequency rate   can be used for increasing of efficiency of generating and amplifying micro devices with filament cathode and matrix field emission cathodes.  

Keywords: double-gap cavity, electrodynamic parameters, mathematical simulation, resonance frequency, characteristic impedance, method of planned experiment

The techniques generate a directivity diagram a slot antenna array with variable polarization. The results of calculation the characteristics of radiation for an array dimension 4x4 elements.

Keywords: AESA, microstrip antennas, spacecraft, remote sensing of the earth.

The paper studies the possibility of quantitative processing of the GPR data for determining the dielectric permittivity and conductivity of a medium (soil samples). Experimental studies are made using radargrams of soil samples with specified values of moisture and conductivity. New methods of quantitative processing of radargrams are proposed in this work to determine the dielectric permittivity and conductivity of soils. The methods were successfully tested on various sections of Russian railways net.

Keywords: layered road profiling, GPR, soil moisture, soil layers profiling, soil conductivity

Suppression of a signal reflected from the underlying surface is being performed for the cause of location of the low-lying objects. Since the spectral characteristics of the signal and noise match, spatial difference is formed by oblique irradiation. Spatial differences are allocated by the radiation pattern. The suppression is performed by forming the zero value in the equivalent radiation pattern. The equivalent radiation pattern is a section of a generalized ambiguity function of the signals. The graphs of equivalent diagrams are shown for several areas of suppression in the view sector. The adaptive system is performing the equivalent radiation pattern zero-value scan of the underlying surface in the view sector. These algorithms are successfully applied to the MIMO system. A feature of the MIMO system is spotted in the task of forming zero values of the equivalent radiation pattern.  

Keywords: MIMO, underlying surface, ambiguity function, adaptive system, passive noise

The problems of mm propagation: rain attenuation,  depolarization and gaseous absorption are considered, and the estimate of the energy potential of wireless mobile data transport networks is given. The dependence on the output power of the distance and the total losses, and the necessary signal levels for different types of modulation being shown.  The estimate of the interfering transmitters effect of side lobes of the antenna is given.  

Keywords: radio wave propagation, mm range, energy potential, rain clutter, side lobes, polar pattern

The possibilities of waveguide elements realization in the structure of multilayered integrated chips of centimeter and millimeter ranges with SIW (Substrate Integrated Waveguide)-technology application are considered. The approaches allowing effectively using in new structures the algorithms and techniques of the electrodynamic analysis and synthesis of passive devices on classical all-metal waveguides are offered. Advantages of use in SIW structure the waveguides of complex cross-section are considered on the example of the microwave band-pass filter.

Keywords: A.A. Gadzieva, V.V. Zemlyakov, S.V. Krutiev

The most effective solutions for recovery of impulse signals in dispersing cable lines can be perfomed on the base of heterojunction SiGe BiCMOS technology and are based on combining in one IC high-frequensy analog blocks on heterojunction bipolar transistors and control unit and adaptive correction of parameters on the base of CMOS transistors. Equalizer chip with adaptive correction of parameters provides hidh quality of recovery of signals with smallest costs for tuning and adjustment of cable lines.

Keywords: equalizer, recovery of signals, heterojunction bipolar transistors

We propose a relatively simple algorithm for the approximate calculation of the inductance per unit length of twisted pair, based on the principle of the geometric distances of its cross-section. Confirmed the efficiency of the algorithm and the high accuracy of the results. A comparative analysis of the mutual inductance per unit length of a long line with the mutual inductance per unit length of the twisted pair.

Keywords: mutual inductance per unit length, a long line, twisted pair

Proposed an approach to calculate the inductance per unit length of twisted pair at microwave frequencies. Analytical relations to calculate the inductance per unit length of double line and twisted pair at microwave frequencies. An efficient algorithm for the approximate calculation of the inductance per unit length of twisted pair at any veins angle.

Keywords: inductance per unit length, microwave frequency, twisted pair, double line, veins angle