Digital phase difference detecting circuit
US4721904A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1985 |
| Grant date | Jan 26, 1988 |
| Priority date | — |
| Expiry date | Dec 17, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R25/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A digital phase difference detecting circuit has a phase shifting circuit for shifting by +90.degree. or -90.degree. a phase of an input signal which has been sampled over a predetermined sampling period, a dividing circuit for dividing an output signal of the phase shifting circuit by the input signal, an operation circuit for performing an inverse trigonometric function operation on an output signal of the dividing circuit, and a subtracting circuit for obtaining the difference between an output signal of the operation circuit and a phase of a reference signal. The resulting output signal of the subtracting circuit indicates the phase difference between the reference signal and the input signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.