| 摘要 |
A two-point modulation device and a two-point modulation method are provided to decrease a chip size of the two-point modulation device and to reduce degradation of a system characteristic. A two-point modulation device includes a first sigma-delta modulator(110), a second sigma-delta modulator(120), and an analog PLL(Phase Locked Loop)(130). The first sigma-delta modulator provides a division control signal based on channel data and modulation data. The second sigma-delta modulator provides a feed forward path modulation signal based on the modulation data. The analog PLL receives the division control signal and the feed forward path modulation signal and generates a VCO frequency signal which follows a reference frequency signal. The PLL includes a frequency divider(140), a phase/frequency detector(150), a charge pump(160), a loop filter(170), and a VCO(Voltage Controlled Oscillator)(180). The VCO receives the feed forward path modulation signal and generates a VCO output in response to an output signal from the loop filter.
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