The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
It is shown, that MITRIS is the best system for the stepwise introduction of digital TV in Ukraine. The system possesses a number of advantageous qualities: high-quality electrical parameters and the possibility of manufacture of its components within the borders of the Ukraine.
This paper presents the description of ERP-system MFG/PRO. The MFG/PRO software is a comprehensive, open-architected, internet-enabled enterprise solution that has a set of new standards for functionality and rapid implementation. The software uses either Oracle or Progress databases, it is compatible with Unix, Windows, and Windows NT, and is accessible all over the Web.It helps executives to decide...
The characteristics of double frequency multi-element slot antennas based on a multi-mode waveguide are investigated by the magnetomotive force method, taking into account the correlation between the slot and the guide wall thickness. The slot with the length equal to a half of the wavelength is shown to be non-radiative at frequencies where higher modes arise. It was also shown that appropriate choice...
The long longitudinal slots cut in the broadwall of a rectangular waveguide are investigated by the method of magnetomotive forces. The thickness of the waveguide walls is taken into account in the numerical calculations. Computer analysis showed the optimization possibility of energy characteristics of leaky-wave antennas on the basis of long longitudinal slots.
The results of theoretical and experimental study of the microstrip-waveguide phased array printed antennas with phase shifters on the basis of ferroelectric films operating in millimeter wave frequency region of 28-30 GHz are presented.
Opportunities of achievement of the polarization crosstalk level of 27 dB in the C-band tracts of satellite communication systems with 500 MHz reception and transmission bands on the basis of the introduction of the absorbing diplexers into a two-port tract are considered.
The results of the design and experimental investigation of a waveguide ferrite phase shifter with magnetic memory for 3 mm-wave phased antenna arrays are discussed. The phase shifter is based on a longitudinally magnetized ferrite rod and operates with circularly polarized waves. The system of magnetization includes a coil and a system of ferrite conductors. This construction of the phase shifter...
Under the Kirghouf approximation in the Fresnel zone of a major reflector location the problem of radiation characteristics optimization for a hybrid optical-type antenna is solved on the basis of analysis of the amplitude-phase field distribution in the aperture of a main reflector.
A construction, calculation relationships and directive characteristics of travelling wave tunable array with central excitation are studied. It is shown that by variation of the corner angle of this array the constant direction of main lobe maximum of the pattern along bisector corner angle in the wide waveband is provided. Examples of calculating the characteristics of these antenna arrays are presented.
The characteristics of a 16-channel mechanically scanned radiometric imaging system, which has been developed in the 8-mm wavelength-range, are discussed. The radiometric array was designed using straight receivers with input low-noise amplifiers operating in 33-38 GHz frequency-band. The system produces a field-of-view image of 90/spl deg//spl times/16/spl deg/ in 10 seconds.
Proposes a new technique of distributed telecommunication networks research. It is based on penetration of parameters, determined analytically, into simulated parameters and vice versa. Introduction of this principle has made analytical and simulation methods widely usable. The results obtained allow one to: consider the influence of equipment unreliability on transmission capacity; simulate the control...
This paper describes creation of the software providing the operation of systems of automated control. Investigated is the application of decomposition methods and algorithms increasing the quality and speed of adaptive control systems of data transmission networks.
The authors consider the possibilities of creation of VHF channel modulator for GBAS systems, in accordance with ICAO recommendations. A model experiment has been carried out.
Presented here are the results of the study of cross-correlation properties of composite Kasami sequence sets for CDMA-systems. Comparative analysis of the results obtained is given.
The modification of the method of complex amplitudes for simulation of RF fields in microwave tube slow-wave circuits is proposed. It allows one to increase the broadbandness of the spectral models based on this method, up to values of the similar parameter obtained based on the method of instantaneous values models. All the advantages of complex amplitudes usage are retained. Modification is in the...
Presented in this paper are the results of experimental study of power two-stage resonance amplifier with a new type of periodic structure operating in 8-mm wavelength range. Authors give advices on the increase of amplifier operation efficiency on the basis of starting currents analysis for each stage.
The experimental research results of a waveguide-coaxial design of the MM-range broadband GaAs Gunn generator are given. A frequency band of mechanical tuning for the generator of /spl sim/23 GHz (from 44 up to 67 GHz) is obtained.
In order to improve the performance of mm-wave IMPATT diode amplifiers, the series diode connection has been effectively used. Series connection of diodes at AC and their parallel connection at DC have been realized in a two-diode balance circuit. The amplifier circuit minimizes losses and overcomes impedance restriction of millimeter wave IMPATTs. The practical amplifier possessed near 100% combining...
We have developed, fabricated and tested an oscillator module of microstrip design on a silicon double-drift IMPATT diode. It has provided output power of /spl sim/40-50 mW in the 8 mm wavelength range. IMPATT diode design involves titanium nitride interstitial phases. This provided high quality and heat tolerance of ohmic contacts.
The results of experimental research on output characteristics of a source of pulse microwave power made as two modules on powerful bipolar transistors are given. The source allows one to receive pulse power P/sub out,i/ /spl sim/1 kW (carrier frequency f = 150 MHz; pulse duration /spl tau//sub l/ = 0.5 ms; impulse frequency F/sub l/ = 10 Hz) on matched load Z/sub L/ = 50 /spl Omega/.
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.