RF power amplifier

There are so many class types for RF PA.Some of them are linear such as A,AB;some of them are like switch type,such as E.How to choose the class type for power amplifier?Does it depend on modulations or something else?Say,for BPSK,lienarity is easy to achieve,so we can use Class E;for QAM64,linearity is more strict,so we should use Class A or Class AB.Is it right?

Thanks in advance!

Yes you are right

thanks for your reply!