it is a small fm transmitter with mp3 player and class F amplifier, powered from USB; it outputs between 2 and 4 watts of power depending on an inductor value, and includes the lowpass filter as part of the output matching. The board is 4 layers, and was combined onto a 10pcs production panel that had some free space left over. QFN soldering isn't really a problem for me, and most of the passives on the board were pre-soldered by the pcb/pcba fab, so I could produce these boards very fast. I think I'll hand a few of these out for free locally to try to get people into radio transmission
it is a small fm transmitter with mp3 player and class F amplifier, powered from USB; it outputs between 2 and 4 watts of power depending on an inductor value, and includes the lowpass filter as part of the output matching. The board is 4 layers, and was combined onto a 10pcs production panel that had some free space left over. QFN soldering isn't really a problem for me, and most of the passives on the board were pre-soldered by the pcb/pcba fab, so I could produce these boards very fast. I think I'll hand a few of these out for free locally to try to get people into radio transmission