The FM25 and the FM-MP3 use a PLL circuit, which keeps the signal from drifting. I'm not sure what the difference is between the FM25 and the FM-MP3.<BR>3.El-Cheapo solution.

A Self-Calibrated 10Mb/s Phase Modulator with -37.4dB EVM Based on a 10.1-to-12.4GHz, -246.6dB-FOM, Fractional-N Subsampling PLL.” About imec Imec performs world-leading research in nanoelectronics.

The RFMD Polaris 2 Total Radio chipset is made up of the RF2723 quad band RF receiver, the RF6007 fractional-N PLL, modulator, digital signal processor and PA ramp controller, and their RF3186 PA.