| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a demodulator which is appropriately operable over a wide frequency band. <P>SOLUTION: In one embodiment, the present invention relates to a PLL phase demodulator using feedforward type error correction. The feedforward type error correction can be performed by obtaining a transmission function for calibrating an equalizer (901) to emulate a modulation response curve of a VCO In a PLL of the PLL phase modulator. In operating, the equalizer is capable of receiving a filtered and integrated version of an error signal generated by a phase detector in the PLL. The equalizer filters the received signal according to the calibrated transmission function. An output of the equalizer is supplied to an adder (903), and the equalized signal and the error signal generated by a phase detector (102) are coupled. The similar calibration including an appropriately calibrated equalizer can be used to deal with a phase tracking error in the PLL frequency demodulator. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
