Hi,
I think you should read the "Power Line Smart Transceiver Data Book" for PL3120/PL3150/PL3170 and go through chapters 4 and 5. There you should find your solution. So go to google and type "Power Line Smart Transceiver Data Book for PL3120/PL3150/PL3170". And go through it as I said.
Thanks for your replay,
chapter 4 and 5 talks only about coupling and power supply circuit design but i want to know about TX amplification and RX front and