Wyniki 1-2 spośród 2 dla zapytania: authorDesc:"Milan CHUPAČ"

Method of measurement of radio transmitters antenna systems

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The paper deals with possibilities of use of thermovision technique in diagnostics of aerial systems of radio transmitters. Graphically presented: heating characteristic of the junction at the transmitter power of 60 % (slack and polluted junction); relationship between temperature of connection (feeder - line, capacitor frame) spacing collar and power; relationship between temperature rise amount of connection and feeder line upon power; thermogram of the junction feeder line - spacing collar, capacity frame; thermogram of the junction feeder line - spacing collar. Streszczenie. W artykule omówiono możliwości wykorzystania techniki termowizyjnej w diagnostyce systemów antenowych nadajników radiowych. Przedstawiono ogrzewanie charakterystyczne połączenia przy mocy nadajnika 60% (także dla zanieczyszczonych i poluzowanych połączeń). relacje Określono związek miedzy wzrostem temperatury złączy a mocą zasilania dla różnych konfiguracji anteny i nadajnika. (Metoda badania termowizyjnego systemów antenowych) Keywords: thermovison, radio transmitters, aerial system, feeder line, spacing collar, junction, capacitor frame, thermogram. Słowa kluczowe: termowizja, nadajniki radiowe, systemy antenowe. Introduction Radiocommunications are subject to the incessant development, which requires demanding and innovation activities, because they with their subsidiary plants complete communication background with all the time wider range of expanding radiocommunicational services. One of the providing services is a local, regional, national wide and foreign broadcasting in the band of SW and VSW for the operator, by means of radio transmitters. For the correct acting of these transmitters besides the restoration and reconstruction, their maintenance is of the same importance. At present, one of the new modern methods utilized not only in diagnostics, research and development but also in monitoring or control of production is the method of thermal fiel[...]

The theoretical synthesis and design of symmetrical delay line with surface acoustic wave for oscillators with single-mode regime of oscillation

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The article deals with the issue of delay lines on the basis of surface acoustic waves for the application in single-mode oscillators. Based on the theoretical analysis concrete delay lines are proposed. Streszczenie: W artykule przedstawiono zagadnienie akustycznych fali powierzchniowych w liniach opóźniających w pojedyńczych oscylatorach. Na podstawie analizy teoretycznej zaproponowano konkretne rozwiązania linii opóźniających (Synteza i projektowanie linii opóźniających z akustyczną falą powierzchniową w pojedyńczych oscylatorach). Keywords: delay line, oscillator, surface acoustic wave. interdigital transducers. Słowa kluczowe: linia opóźniająca, generator, akustyczna fala powierzchniowa, przetworniki cyfrowe Introduction As selective elements of oscillators of harmonic vibration besides the band-pass filters are also used delay lines (DL) and resonators as a perspective acoustic-electric components based on surface acoustic waves (SAW). From the stability point of view we can classify these oscillators among the ones with volume acoustic waves and LC oscillators. The quality factor of vibrating system of oscillators with SAW is in the range from 100 to 10 000 while these oscillators work with the basic harmonic in the frequency range from 10 MHz to 1,5 GHz. Their main advantages are small dimensions, low weight, high mechanic strength, low sensibility to vibrations and a possibility to construct oscillators without using inductors. That is just what increases the perspectives of their manufacturing and the wide possibilities of their usage in radio electronics, telecommunications and concurrently the necessity to work out the questions connected with their theory and manufacturing In the article, the DL with SAW for single-mode oscillators are investigated and the single-mode oscillation conditions of oscillators are derived and based on the deduced theory the concrete DL are proposed for various purposes of usage. 1. Th[...]

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