Timothy P. Hulick

This paper is the first of two presenting the Digital Amplitude Modulator and the Digital Linear Amplifier, the former being a precursor to the latter.

Linear amplitude modulation in very high-power full carrier systems requires rather large solid state or vaccuum tube devices in Medium Wave (MW) and Short Wave (SW), VHF and UHF television transmission broadcast systems. The analog format for these systems for MW and SW is simple, full carrier, 100-percent AM with no phase modulation. For vestigial sideband television, and any of the X-QAMs, X-VSBs, or any other digital format requiring both AM and PM to describe the envelope vector of the modulation signal, simultaneous AM and PM are required.

This paper presents a new, nearly distortion-free approach to digitally synthesized analog amplitude modulation, boasting very high power efficiency and linearity.