公开(公告)号：US20180367157A1

公开(公告)日：2018-12-20

申请号：US15967026

申请日：2018-04-30

Applicant: RENESAS ELECTRONICS CORPORATION

Inventor： Wataru NAITO ,  Takeshi KONDO

IPC: H03M1/10

CPC classification number: H03M1/1023 ,  H03M2201/4212 ,  H04L2027/0065 ,  H04L2027/0067

Abstract: Degradation of a reception performance by an image signal is reduced. A semiconductor device includes: an oscillation circuit configured to generate a local signal; a mixer configured to multiply a reception signal by the local signal; an analog filter configured to filter a signal output from the mixer; an AD converter configured to digitalize a signal that has passed through the analog filter to generate a first signal; a digital filter configured to filter a signal that has passed through the AD converter to generate a second signal; a power comparator configured to detect the power difference between the first signal and the second signal; a register configured to store a theoretical power difference; and a determination unit configured to determine a frequency of the local signal based on the power difference from the theoretical power difference.