Title :
An alternative approach to improving the efficiency of high power radio frequency amplifiers
Author_Institution :
Guangxi Broadcasting & TV Sch., China
fDate :
6/1/1992 12:00:00 AM
Abstract :
The concept of using fourth-harmonic rather than third-harmonic resonant circuits in the tuned plate circuits of high-power radio-frequency amplifiers to improve operating efficiency is proposed. The advantages are circuit simplicity, greater stability, and simpler adjustment than with third-harmonic-enriched amplifiers because the grid excitation voltage can be sinusoidal. Improvements in plate efficiency, envelope distortion, and carrier shift characteristics are comparable to those achieved with third-harmonic designs: however, implementation is simpler and the amplifier more stable because the requirement to maintain a constant grid current under conditions of plate modulation becomes less critical
Keywords :
power amplifiers; radiofrequency amplifiers; carrier shift characteristics; constant grid current; envelope distortion; fourth harmonic resonant circuits; grid excitation voltage; high power radio frequency amplifiers; operating efficiency; plate efficiency; plate modulation; stability; tuned plate circuits; Cathodes; Frequency; High power amplifiers; Power amplifiers; Power system harmonics; RLC circuits; Radio transmitters; Radiofrequency amplifiers; Switches; Voltage;
Journal_Title :
Broadcasting, IEEE Transactions on