Am transmitter with an offset voltage to the rf stage to compensate for switching time of the modulators

Abstract From the Canadian patent

Abstract of the Disclosure An AM transmitter of the type including apfor generating a subcarrier signal, pulse width modulating the subcarrier with audio, and amplifying the resulting pulse width signal using active devices operating in the more efficient switching mode is described. The amplified pulse width signal is passed through a low pass filter wherein the audio is recovered and used to amplitude modulate a signal in a radio frequency stage. The improvement herein includes means for providing an offset voltage to the RF stage so that the system will develop zero carrier output when the pulse width of the modulating signal to the active devices has a relatively small finite value. -1-