Circuitry for processing signals occurring in a heterodyne interferometer
US6147763A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 27, 1999 |
| Grant date | Nov 14, 2000 |
| Priority date | — |
| Expiry date | Dec 27, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/45
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A signal processing circuit for a reference signal occurring in a heterodyne interferometer and a measured signal. The underlying frequency modulation of the radiation source of the heterodyne interferometer results in phase jumps in both signals. Signal filtering of both the reference signal and the measured signal with a gate signal removes from both signals those signal components that have the same phase sign. Further simplification of the signal processing results from signal interpolation by band pass filters and signal down-mixing into a lower frequency range below the heterodyne frequency. The input signals processed by the circuit can be further processed by a conventional phase comparator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.