| 摘要 |
#CMT# #/CMT# The method involves delivering a sample at each instant with the help of a synchronization signal. Products of two samples are calculated from the sample delivered at same instant, where one of the samples is proportional to result of multiplication of a signal value at an instant by a value of an impulse response of a finite impulse response filter. One of the products is added with another produce from the calculated products during observation period, resulting from an addition corresponding to a value estimated from a derivative. #CMT# : #/CMT# Independent claims are also included for the following: (1) an information recording medium comprising instructions to perform a synchronous demodulation method (2) a synchronous demodulator comprising a sample generator (3) a magnetic field sensor comprising a synchronous demodulator. #CMT#USE : #/CMT# Method for synchronously demodulating a low frequency signal by using a synchronous demodulator in a magnetic field sensor (all claimed), for estimating an angular position and angular speed of an object i.e. disc. #CMT#ADVANTAGE : #/CMT# The method eliminates or reduces retardation proportional to the observation period, thus strongly reducing tailing error in the demodulator. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a flowchart of a method for synchronously demodulating a low frequency signal in a synchronous demodulator. |
