Ben Jackson wrote:
On 2006-07-12, Roy Lewallen wrote:
The Class C transistor amplifiers I design and use most certainly
saturate. I believe that's standard practice for solid state amplifiers.

And as a followup, is the power dissipation in the final controlled
by the duty cycle of the pulses (or number of degrees of conduction
more generally if the input is not a square wave)?

Not really, although it's a factor. What counts more is the transistor
voltage when the current is maximum, and the relationship between V and
I during switching. This in turn depends on the nature of the output
network among other things. If you really want to find out more about
the efficiency of a saturating transistor amplifier, look up some of the
papers on "class E" operation by Sokal & Sokal and by Raab. They
basically took a time-domain approach to find the optimum conditions for
maximum efficiency of a saturating class C amplifier. I've never
consciously designed a "class E" amplifier, but have gotten more than
85% collector efficiency from saturating Class C amplifiers at the 10
watt input level.

Roy Lewallen, W7EL