A new, high efficiency, digital, modulation technique for AM or SSB sound broadcasting applications

Saturated pulse-width modulation (SPWM), a form of modulator control signal that uses a flash converter for analog-to-digital conversion, is discussed. SPWM is used to modulate high-power RF amplifiers. The operations of a flash converter, formed from a plurality of comparators, and a ring modulator, an address rotation circuit that performs a controlled sequence defining which comparator commands a particular power switch, are described. >