公开(公告)号：US20190181888A1

公开(公告)日：2019-06-13

申请号：US16154459

申请日：2018-10-08

Applicant: RENESAS ELECTRONICS CORPORATION

Inventor： Wataru NAITO ,  Noriyoshi IZUMI ,  Kazuhiro KIJIMA

IPC: H04B1/00 ,  H04B1/10 ,  H03D7/16 ,  H03D3/00 ,  H03H19/00 ,  H04B1/30 ,  H04B1/403

Abstract: An IF filter band-limits an intermediate frequency signal outputted from a mixer. An AFC unit controls the oscillation frequency of a PLL so that the frequency of the intermediate frequency signal is a predetermined frequency. When the AFC unit controls the oscillation frequency of the PLL, a band control unit controls the passing characteristic of the IF filter to the passing characteristic of a wide band, and after the completion of the control, controls the passing characteristic of the IF filter to the passing characteristic of a narrow band. A frequency correction unit refers to a filter information storage unit, and corrects the oscillation frequency controlled by the AFC unit according to the difference between the center frequency of the passband of the passing characteristic of the wide band and the center frequency of the passband of the passing characteristic of the narrow band.