| 摘要 |
PROBLEM TO BE SOLVED: To optimize the sampling rate of an output signal in accordance with the band ratio of a modulation band to the RF frequency of a received signal. SOLUTION: A sampling mixer comprises a history capacitor 6 that integrates input signals current-converted for a continuous time interval; rotation capacitors 7-14 that repeat the integration and discharging of the input signals; a digital control 104 that controls the integration intervals of the rotation capacitors 7-14; and a control part 105 that controls the discharging of the rotation capacitors 7-14. In the sampling mixer, the number of ones of the rotation capacitors 7-14 that are simultaneously connected to a buffer capacitor 15 is changed in accordance with the band ratio of the modulation band to the RF frequency. In this way, the decimation ratio is made variable, whereby the quantized noise during the A/D conversion can be reduced. COPYRIGHT: (C)2007,JPO&INPIT
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