| As for the TV transmitter of UHF of which the power grade is above 10KW, the valve power amplifier such as the electron tube, klystron and IOT are widely adopted in high-frequency linear power amplifier. To compare with transistor (complete solid-state) high-frequency linear power amplifier, there are some disadvantages: bad stability and reliability, low efficiency, high cost for operating, huge cabinet, heavy maintenance work load, low security for high-voltage electricity offering, and to ensure the continuance of TV program, the transmitter must be operating with main frame and spare frame.Recent years, HARRIS and MAR in USA, PHILIPS in HOLLAND, THOMSON in FRANCE and TOSHIBA, NEC in Japan have been doing efforts in researching and exploiting of new material and new kinds of transistor amplifier and have offered varieties of schemes. As the great reform and progress in a lot of techniques have been made in the new generation of semiconductor high-frequency power amplifier, valve power amplifiers are replacing by complete solid-state high-frequency linear power amplifiers gradually. In this aspect technology abroad is far more higher than inland, almost dominates the manufacture of UHF complete solid-state TV transmitters above 10KW.On the base of summarizing and reference to the achievement of UHF complete solid-state high-frequency power amplifier abroad, the author have made a deep research in UHF 10KW electron tube TV transmitter power amplifiers which are widely used inland, and asked for ideas of a lot of engineers of Chongqing TV transmitting station, brought forward a practicable solidification scheme under the guidance of prof. Gao Chao and prof. GuoYongcai, and made a successful practice at Chongqing TV transmitting station. Through the research of this subject, my level of scientific research has been advanced, the operational ability is exercised and the knowledge is broadened. The main contents and creative results of the paper are given as follows:(1) Introduced the special requirement of output power for TV transmitter, on condition that the wireless coverage of TV signal is achieved at UHF, analyzed the important meaning of the research in high frequency linear power amplifiers of UHF transmitter. Pointed out that it is a very important subject to look for the advanced, high-efficiency, useable, stable, reliable high linear power amplifier of UHF TVtransmitter by now.(2) Made a research in the composing mode of the high-frequency linear power amplifier of UHF complete solid-state transmitter. Introduced the method of multi-transistor modular design, for the output ability are limited in single high-frequency power transistor. Analyzed the outstanding advantages of UHF complete solid-state transmitter.(3) Made a research in the new technical fruit and future prospect of currently technology of high-frequency power transistor. Introduced the advantages and disadvantages of the bipolar transistor, MOS-FET transistor, LDMOS-FET transistor, and the parameters of MOS-FET transistor, LDMOS-FET transistor in the UHF, which presents the advanced technology over the world.(4) Specially made a research in the key technology of UHF complete solid-state high-frequency linear power amplifier: balancing transistor high-frequency linear power amplifier and the technology of 3dB power integrating (allocating).(5) From August, 2002 to April, 2003, on the base of analyzing of 10KW valve TV transmitter of channel 14, Chongqing TV transmitting station, brought forward process the solidification scheme to 400W valve power amplifier of the driver. After advance, technical index keeps stable, equipment operates normally, running cost has been saved, ensured the broadcasting of CQTV-2 safely. Practicing proved that this scheme achieved the aim that to be advanced, high efficiency, practical, stable, reliable. Not only accord with the national instance but also practical, having practical means and are valuable to be popularized.
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