| 摘要 |
A multi-mode loop frequency modulator (10) for modulating a carrier signal according to various modulation pulse shapings and data signals to provide a modulated output signal (VCOout). The multi-mode loop frequency modulator (10) includes a waveform generator (12) and two multiplexers (14,38) to perform various pulse shaping filtering and/or predistortion of the pulse shaping filter impulse response for either a dual port modulation or for a single port modulation. The waveform generator (12) can optionally provide interpolation for input frequency deviation and can optionally provide scaling for various reference frequency clock signals provided by the crystal (30) and the reference divider (28). The low pass filter (22) is used for providing the phase lock loop filtering and also for providing a smoothing filter for the high port DAC (18). <IMAGE>
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