Power amplifier input and output stage

I have designed a CMOS class E power amplifier in cadence virtuoso of frequency 1GHz output resistance of 50ohm and input voltage source of 3.3v

I have seen a tutorial for a simple power amplifier in that they have given a input stage and output stage also some matching network along with it.

For what we are using the input and output stage why cant we able to use a simple class e for all analysis now what i want to do to proceed my project

Please help me
Thank you in advance