So one of my side projects is a pager "network" (if you can call it that) based on a Motorola GM340 VHF radio, a homebrew TNC, and a box of recrystalled Memo Express pagers. As a side project to that, I've designed a pager around a Silicon Labs Si4362 receiver chip and an STM32 microcontroller.

This is all fun for sending messages one way, but -- says I -- what if I could send messages both ways, or even do some form of packet radio?

SiLabs do another chip series, the Si446x range:

http://www.silabs.com/products/wireless/EZRadioPRO/Pages/Si446x.aspx

These cover 119 to 1050 MHz (so 2m and 70cm ham are definitely covered), up to an output power of 100mW ( 19dBm) on the internal PA, or 1W with an external PA.

Does anyone know of an RF PA design which I might be able to use (perhaps with slight modification)? I only need a few Watts out.

I've seen the Mitsubishi modules, they're nice, but probably a bit big.

There's a SiLabs app-note (AN656, http://www.silabs.com/Support Documents/TechnicalDocs/AN656.pdf) which covers using the NEC NESG270034 RF SiGe BJT as a PA, but said part is now long discontinued with no alternatives listed anywhere I've looked. Is anyone aware of any similar parts?

Thanks!