Help me about Class F Power Amplifier

I'm a beginner in RF Field.

I want to design GaN HEMT Class F Power Amplifier in last.
First, I want to really understand the Class F.
Please suggest me about the Class F theory or text book that I should read or anything I should do.

Thank you.

http://www.highfrequencyelectronics...._RaabPart2.pdf
http://www.cree.com/products/pdf/GaN...ith_80_PAE.pdf

RF CMOS Power Amplifiers
By Mona M. Hella, Mohammed Ismail, Inc NetLibrary, ebrary, Inc - Kluwer Academic Publishers (2001) - Hardback - 112 pages - ISBN 0792376285


good book