Local Multipoint Distribution Service (LMDS) is a broadband microwave communications technology offering a low-cost and multifunctional solution for terminal access applications. This paper develops a rectangular waveguide-based duplexer with a square-ridge T-junction for LMDS. The design of a rectangular waveguide-based metal diaphragm filter in the E-plane is described. The metal diaphragm of this filter can be processed using methods such as etching, ensuring high precision and low cost. The characteristics of a rectangular waveguide-based T-junction in the H-plane used in the duplexer are analyzed.

Keywords: microwave duplexer, E-plane metal diaphragm, microwave filter, ribbed T-junction, local multi-drop distribution service

A model is presented for the calculation of thermoelastic stress and displacement  in semiconductor structures
due to laser processing. Developed software based on the model allows to determine the optimal parameters of laser processing with taking into account the physical and topological parameters of the structure. The model is divided into two tasks: the non-stationary heat  conduction equation is solved, and the equilibrium equations and Hooke's law. For equations solution was used the finite difference method.

Keywords: Laser processing, thermal stress, finite difference method

The modification of the most common steganography method for various container is presented. This modification allows to increase the resistance of steganography to the statistical analisys. A comparative analysis of the effect of the traditional LSB matching method and the proposed modification to the frequency histogram of sample values ​​in the container is presented.

Keywords: steganography, steganalysis, information security, embedded data transfer

The catalytic activity of Pt/C and PtxNi/C electrocatalysts prepared by  borohydride methode was studed. It was established that the specific activity  of fresh prepared Pt3,7Ni/C  catalyst  in oxygen  electroreduction  reaction is higher in compare with Pt/C material. After treatment of Pt3,7Ni/C material in the hot acid  nickel in the surface layers of nanoparticles was dissolved and the composition of nanoparticles was changed to Pt5,6Ni. The electrochemical surface area of the Pt5,6Ni catalyst and specific activity was slightly decreased after corrosion treatment. 

Keywords: platinum electrocatalysts, corrosion stability of the nanoparticles, fuel cells, X-ray diffraction, borohydride synthesis

The temperature dependencies of the main parameters of p-channel MOSFET model in a temperature range 20 ... 300 K are measured. The universal formal four-parametric model, which allows approximating all experimental temperature dependencies with the relative error less than 1 % is proposed. The model is intended for the MOSFETs which are applying in low-noise amplifiers of the radio-receiving devices of an optical and infrared range on astronomical satellites, radio telescopes and space observatories. The presented results can be used to simulate the temperature modes of MOSFET amplifiers in SPICE-type electronic simulators. The solution of this problem will predict uptime device when the temperature changes in the cases of emergency or extraordinary situations and also will allow optimizing the choice of refrigerant and increasing the reliability of the amplifier in the conditions of cryogenic temperatures.

Keywords: MOSFET, MOSFET parameters, cryogenic temperature, parameters measurement, temperature dependencies

The results of analysis of computational aspects of the method of obtaining the XANES spectra for Ru L2 ,3-edges by integrating the dipole transition matrix elements involving DFT. The convergence of the numerical integration procedure for the parameters used in the earlier papers, crystals as an example [Ru (NH3) 6] 3 +. More specifically, it is proved that it is possible to use a small area of ​​integration and big enough step between points, which helps to minimize the requirements for computing power and offers the prospect of using this method for the simulation of the XANES spectra in coordinated ruthenium catalysts for splitting water research in the field of solar energy.
Keywords: RuLedge, XANES, DFT, density functional theory, X-ray absorption spectroscopy, geksoaminoruteny, Ru (NH3) 6.

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