It has been 10 years since I last worked in electronics. But I wonder if anyone has come across this implementation of the PWM? All that I have seen with the PWMs is that when the signal goes high the power transistor turns on and then turning it off when the signal goes low. Why not have two generators and two transistors, one transistor that opens and turns on generator [[a]] when the signal goes high and the other transistor that opens when the signal goes low turning of [[a]] and turning on generator [[b]]. This way you always have a generator in the on state-they are just alternating. You would theoretically double your output.

The change to the circuit would be minimal when dealing with a true 50% duty cycle, though I know that is not the case in most implementations. The two transistors/generators would operate in parallel.