The article deals with the study of quasi-optimal TOA discriminator of an onboard echo-signal tracker of the altimeter carried by a space vehicle. In modern space-based altimeters, final data processing is imposed on the ground-based center receiving information from the spacecraft through a telemetry line, while the main task of an onboard delaylocked loop is to reliably retain the received echo-signal within the tracking window. The optimum discriminator of an onboard loop providing the potential accuracy of time measurement can appear difficult to implement. In the discriminator considered an error signal is proportional to the time mismatch between the half power point of the received power pattern and the tracking window. The equation for the equivalent time fluctuation variance is derived. It is also found that the discriminator proposed is as good at tracking precision as the maximum-power-point discriminator and maximums teepness discriminator, being at the same time much more attractive in terms of hardware complexity. The theoretical results are well consistent with the computer simulation. This simulation is performed both directly and using different methods of censoring the error signal at the discriminator output to effectively neutralize possible abnormal errors that are not taken into account by theoretical analysis.

The problem of functional diagnosis of digital devices forming a network of state automata is considered. This task for the network components is supposed to be solved, and the corresponding diagnostic devices for them are provided. The possibility of their population transformation into the tools for the entire network diagnostics is shown. The result of the transformation with the restrictions on the number of components with errors is simplified in compare with the original population. A procedure is proposed allowing to find analytical expressions defining an auxiliary control and an error discriminator for the most probable case of error localization (all errors are concentrated in a certain component of the network). The first part of the article provides a solution of the functional diagnosis problem for the case when the parity functions of all components are scalar, and the class of detectable errors is given by unit multiplicity. Next, the result generalizes for the case of vector functions, where multiple errors can occur. The procedure minimizes the sought for functional diagnosis devices with respect to the order when preserving the initial detecting ability within any network component. The obtained results are illustrated by an example of construction of functional diagnosis equipment for ranging signal processing device in broadband short-range radio engineering navigation system.

This article provides a technique for design and simulation of an active second order band-pass filter with lineal tuning of Q-factor and independent tuning over a wide range of resonant frequency and transfer coefficient. The tunable band-pass RC-filter is required for selective processing of electric signals in radio engineering systems and devices, as well as in in-formation measuring systems, the acoustic and hydro acoustic equipment, including devices for noise and vibration analysis. The band-pass RC-filter is required in equalizers for allocation of useful signals.

It is shown that the filter is constructed on the basis of the active second order correcting link with the use of tunable RCcircuit T-bridge. Calculation formulas for filter parameters are received, i.e. resonant frequency, polar Q-factor and transfer coefficient. It is shown that in the filter circuit these parameters can independently be tunable over a wide range. Resonant frequency of the filter is tuned by means of dual variable resistors with the Q-factor and transfer coefficient remaining constant.

Polar Q-factor is regulated by change of resistance of the variable resistor with transfer coefficient and resonant frequency remaining constant. The transfer coefficient changes by means of another variable resistor.

The conclusions of expressions for the tuned parameters of the suggested circuit of the active band-pass RC-filter confirming the research are provided, as well as the filter frequency characteristics and tunable parameter diagrams. Filter implementation is supported by simulation with the use of MicroCap10 software.

An experimental and theoretical study of the formation processes of "impurity" phase inclusions in ferroelectric oxides is carried out via example of polycrystalline lead zirconate-titanate (PZT) films. A feature of these compositions is relatively high volatility of lead oxides, which can lead to deficiency of these components in the composition of the ferroelectric film formed during high-temperature crystallization. To avoid lead losses, some excess is added to the solution in the process of synthesis. Experimental samples of PZT films are obtained using sol-gel method with different contents of lead oxide, the crystallization of the ferroelectric phase of the films is carried out in air at 600 °C. In the films, the inclusions of lead oxide impurity phase are found, and the size distribution of these inclusions are obtained. Model concepts are presented and a system of equations is proposed describing the dispersed inclusions formation kinetics of new phases of different stoichiometric composition at the interfaces in polycrystalline films of multicomponent ferroelectric oxides due to bulk diffusion and grain-boundary segregation. Comparison of the experimental data with the theoretical model gives qualitative agreement. The approach generality makes it possible to extend the model to other systems of multicomponent ferroelectric polycrystalline materials.

The use of the miniature controlled reception pattern antennas (CRPAs) in GNSS equipment is one of the trends in GPS, Baidow, GLONASS development. A miniaturized GPS antenna array technology reduces the size of the antenna elements and the array dimensions. Miniature CRPAs are in demand not only with mass consumer of GPS/GLONASS house-hold equipment, but with expert users of complex hardware as well, where high-tech multi-sensor miniature antenna systems (AC) can be applied. Such types of AC used for intelligent control of spatial selectivity are considered as antenna arrays. The advantages of miniature CRPAs with anti-jamming capability include possibility to be installed on vehicles where it used to be impossible due to their size. The negative effect of miniaturization is in degradation of some antennas characteristics, such as gain, suppression of the reverse lobe of radiation pattern (RP), a heterogeneity of RP. In miniature antennas, the resonator interinfluence increases, that leads to distortion of individual emitters RP and to the in-crease of the total RP lobe of the antenna array irregularity, as well as the width of RP lobe. Designers take special measures to reduce the interinfluence of the resonators. However, they are not fully described in the available literature. Therefore, the achieved performance of miniature CRPAs is in great interest. The final criterion (from a consumer point of view) is in effective functional of a device containing a miniature CRPA, the degradation of its parameters in compare with traditional CRPA equipment of expert users. The authors focus on property investigation of miniature CRPAs manufactured primarily by US industry. Specifications of two antennas and some expected details of the miniaturized antenna array technology are described along with the test results of their ability to perform the objective function jammer suppression. The article contains the results obtained from independent testing of electrodynamics parameters of miniature L1/L2 frequency CRPA and its design analysis. The experimental data of sensor interinfluence are outlined. The measures to reduce the sensor interinfluence are take into account. The efficiency of the miniature antenna is estimated in the process of interference suppression by means of computer simulation. The Monte-Carlo method is applied. For the sake of generality, two types of algorithm for interference suppression are used.

The article proposes a solution of a problem of polarization error compensation for radar object direction finding by means of conical scan method. The solution is considered at signal processing level that makes possible to avoid polarization limitations in antennas engineering. The purpose of the article is to substantiate a model for polarization-induced errors by conical scan direction finding method and to develop an algorithmic technique for the considered method correction with regard to arbitrary polarization conditions of radar interaction. The results are presented by analytical model along with quantitative estimates of polarization-induced errors of direction finding and the computational procedure of the error compensation as well as by analysis of imperfectness factors for the proposed procedure exposing its practical applicability.

The basis of spin filter operation is the possibility to obtain different population of states with spins up and down for free electrons. However, in a magnetic macroscopic field, scattering by heavy atoms reduces their population density by 106 times. To obtain the maximum possible degree of spin polarization it is proposed to use ferromagnetic EuO in semiconductor superlattices, e. g. EuO–SrO. The article substantiates the creation of a spin filter based on a superlattice composed of SrO and EuO nanolayers. The scheme of ferromagnetic semiconductor EuO energy levels is demonstrated as well as splitting of 5d EuO levels by crystal field. The position of 4f 7-multiplet and the energy of formation of triplet exciton are determined.

The algorithm for calculating electrodynamic characteristics of hybrid types of waves propagating in double ridged waveguide with piecewise-layered dielectric filling is presented. The double ridged waveguide structure with dielectric plates installed between the ridges, and with dielectric sample sandwiched between the dielectric substrates is consid-ered. The calculations are carried out using the method of partial regions. The presented algorithm takes into account the electromagnetic field components singularities near the dielectric and metal edges of the waveguide. The technique for calculating the electromagnetic energy losses in the double ridged waveguide with a piecewise layered dielectric filling is provided. The classification of hybrid waves is given. The spatial structures of electromagnetic fields and their planar projections (front view, top view, side view) for the first two HEwaves and the first EH-wave are demonstrated. Cutoff fre-quencies and propagation constants of HEand EH-waves are calculated. The results obtained using the described meth-od and numerical approach are compared. Then the results are analyzed.