In-phase/in-quadrature demodulator for spectral information of interference signal
US7864327B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 9, 2009 |
| Grant date | Jan 4, 2011 |
| Priority date | — |
| Expiry date | Jul 17, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J3/45
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Sinusoidal in-phase and in-quadrature signals at a given spatial frequency are combined with the irradiance signals generating a correlogram of interest and integrated over the length of the correlogram data-acquisition scan. The integration outputs are then used to calculate the amplitude and the phase of the correlogram signal at the selected spatial frequency, thereby producing targeted spectral information. The signal generator used to generate the in-phase and in-quadrature sinusoidal signals may be scanned advantageously through any desired range of spatial frequencies, thereby producing corresponding amplitude and phase spectral information for the correlogram. Because the procedure produces spectral information independently of the number of data frames acquired during the interferometric scan, it is materially more rapid than conventional FFT analysis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.