公开(公告)号：US20140028355A1

公开(公告)日：2014-01-30

申请号：US13727948

申请日：2012-12-27

Applicant: NATIONAL TAIWAN UNIVERSITY

Inventor： SHEN-IUAN LIU ,  KUN-HSUN LIAO

IPC: H03B21/00

CPC classification number: H03B21/00 ,  H03L7/081 ,  H03L7/0814 ,  H03L7/1976 ,  H03L7/23

Abstract: The present invention discloses a noise filtering fractional-n frequency synthesizer and an operating method thereof. The noise filtering fractional-n frequency synthesizer comprises a filter, a frequency calibration loop, a phase calibration loop and a digitally controlled delay line. The filter receives a first frequency division signal and generates a filtered signal. The frequency calibration loop is coupled to the filter and generates a first control signal. The phase calibration loop is coupled to the filter and the frequency calibration loop, and generates a second control signal. The digitally controlled delay line is coupled to the phase calibration loop and receives the second control signal. Thus, quantization noise of the fractional-n frequency synthesizer can be reduced, and phase noise of the fractional-n frequency synthesizer can be improved. In addition, the system remains locked after the filter outputs the signal.

Abstract translation: 本发明公开了一种噪声滤波分数n频率合成器及其操作方法。 噪声滤波分数n频率合成器包括滤波器，频率校准回路，相位校准回路和数字控制延迟线。 滤波器接收第一分频信号并产生滤波信号。 频率校准环耦合到滤波器并产生第一控制信号。 相位校准环路耦合到滤波器和频率校准环路，并产生第二控制信号。 数字控制的延迟线耦合到相位校准回路并接收第二控制信号。 因此，可以减小分数n频率合成器的量化噪声，并且可以提高分数n频率合成器的相位噪声。 另外，滤波器输出信号后，系统保持锁定状态。