Abstract :
THE universal use of amplitude modulation in radio broadcasting service has led to several formidable problems in the design of broadcast transmitting equipment. Improvements in technique which permitted the complete modulation of a carrier (100 per cent modulation) raised new problems in connection with the conversion efficiency of the final radio-frequency amplifier stage. Continued research has resulted in such developments as the high-level plate-modulated amplifier, the high-efficiency linear amplifier, outphasing modulation, and others.
