Before doing the final layout, we started some experiments with the BLF2425M9. Mounted on a homebrew prototype PCB this Mosfet generated 22 watts out from 500mW input with almost 50% efficiency.
(nice for use in portable 60cm dishes).
The plan for the final PCB is now as follows:
1) 2.4 GHz SAW filter at the input (as recommended for the Amsat TX board)
2) MHT1008 amplifier
3) LP filter
4) --- CUT ---
6) BLF2425M9 amplifier
7) LP filter
at step 4) there are simply a couple of holes in the PCB, the PCB can be cut here into 2 parts. So if only the MHT1008 is needed, the PCB is broken at 4) and the other part is thrown away (the PCB is very cheap ).
If one needs both stages (i.e. for higher gain), then he uses the complete board with a gain of up to 34 dB.
Some applcations (i.e. the Amsat Mixer board) need a gain of >17 but less then 34 dB. To adjust the gain to the needed value a simple attenuator (0,5 watts SMD resistors) can be mounted.
This week we are doing the measurements with the BLF2425M9 board and also design the low pass filters.