Demodulation device

摘要

A demodulation device for demodulating a base signal from a composite signal, which is composed of a carrier wave and a sensor modulation signal of the base signal. The demodulation device determines a difference between the composite signal of a former-half period and the composite signal of a latter-half period to be a pre-correction base signal. The former-half period is a one-half period of a sampling period starting at one of a local maximum and a local minimum of the carrier wave. The latter-half period follows the former-half period. The demodulation device determines a reference level from the composite signal and determines a signal level of a post-correction base signal based on a ratio between a signal level of the pre-correction base signal and the reference level.

主权项

1. A demodulation device for demodulating a base signal from a composite signal, which is composed of a carrier wave and a modulation signal of the base signal, the demodulation device comprising:
a pre-correction base signal determination part, which determines a difference between the composite signal of a former-half period and the composite signal of a latter-half period to be a pre-correction base signal of the base signal, the former-half period being a one-half period of a sampling period starting at one of a local maximum and a local minimum of the carrier wave and the latter-half period following the former-half period; a reference level determination part, which determines a reference level from the composite signal; and a base signal determination part, which determines a post-correction base signal based on a ratio between the pre-correction base signal determined by the pre-correction base signal determination part and the reference level determined by the reference level determination part.