Abstract
Conventional power amplifiers are either linear with
 poor efficiency or efficient with poor linearity. 
In this seminar the different classes of the most common 
power amplifiers are presented showing how each amplifies 
the input signal. Then the class-S power amplification 
technique will be explained, showing that by operating 
the power transistors in switched mode operation 
theoretically efficiencies of 100% are possible. The 
final part will focus on the signal conditioner namely a
 sigma delta modulator, that converts the signal into a 
1-bit stream of data that is highly linear and can have very 
high SQNR