Frequency modulation-based folding optical analog-to-digital converter
US6064325A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 11, 1998 |
| Grant date | May 16, 2000 |
| Priority date | — |
| Expiry date | Aug 11, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F7/00
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A frequency modulation-based optical analog-to-digital converter utilizes a downward-folding, successive approximation approach. A series of stages is utilized to generate bits in the digital signal. In each stage, complementary low and high bandpass filters collectively cover a bandpass frequency range from a low frequency to a high frequency. The high frequency filtered signal from the high bandpass filter is observed to obtain a bit in the digital word. By performing the folding operations in the frequency domain, the converter avoids the difficult task of optical power subtraction, relying instead on frequency down-conversions. The high frequency filtered signal passed by the high bandpass filter is then downconverted and added to the low pass filter signal to generate a modulated signal for the next stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.