Patent ID: 8488497

Claim:
An asymmetrical phase rotation device into which a phase difference signal, which is a difference between a phase signal and its immediately previous phase signal measured in radians, is inputted, for performing an operation on the phase difference signal and outputting a resultant signal, comprising: a coordinate system converter that separates an input signal into a phase signal and generates a phase difference signal by calculating in radians a difference between the separated phase signal and the phase signal separated immediately previously thereto, and outputs the phase difference signal; and an asymmetrical phase rotation unit for performing one of an operation of subtracting 2π radians from a value of the phase difference signal when the value of the phase difference signal is greater than a predetermined positive threshold value; and an operation of adding 2π radians to the value of the phase difference signal when the value of the phase difference signal is less than a predetermined negative threshold value, wherein when performing the operation of subtracting 2π radians from the value of the phase difference signal, the asymmetrical phase rotation unit further performs an operation of adding a positive value to a predetermined number of values of the phase difference signal that precede the value of the phase difference signal and adding a positive value to a predetermined number of values of the phase difference signal that follow the value of the phase difference signal, the total of the positive values being 2π radians, and when performing the operation of adding 2π radians to the value of the phase difference signal, the asymmetrical phase rotation unit further performs an operation of subtracting a positive value from a predetermined number of values of the phase difference signal that precede the value of the phase difference signal and subtracting a positive value from a predetermined number of values of the phase difference signal that follow the value of the phase difference signal, the total of the positive values being 2π radians.