Apparatus for detecting the amplitude and phase of an A.C. signal

摘要

An apparatus for detecting the amplitude and phase of an a.c. signal. The apparatus includes a signal detection circuit for detecting the a.c. signal, a signal splitting circuit for splitting the detected a.c. signal into first and second a.c. signals out of phase with each other by 90 DEG . The signal splitting circuit includes a low-pass filter, and a differentiation circuit. The apparatus also includes a phase compensation circuit coupled to the signal splitting circuit for receiving the first and second a.c. signals from the signal splitting circuit and for advancing the phase of an output signal of the apparatus by the phase lag of the low-pass filter. The phase compensation circuit also includes an amplitude and phased detection circuit for detecting the amplitude and phase of the detected a.c. signal by implementing a polar coordinate transformation of the first and second a.c. signals received from the signal splitting circuit.