Wide-area sensing of amplitude modulated signals
US11375146B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 26, 2020 |
| Grant date | Jun 28, 2022 |
| Priority date | — |
| Expiry date | Aug 14, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/516
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Amplitude-modulated (AM) signals spanning a spatial wide area can be efficiently detected using a slowly scanning optical system. The system decouples the AM carrier from the AM signal bandwidth (or carrier uncertainty), enabling Nyquist sampling of only the information-bearing AM signal (or the known frequency bandwidth). The system includes a staring sensor with N pixels (e.g., N>106) that searches for a sinusoidal frequency of unknown phase and frequency, perhaps constrained to a particular band by a priori information about the signal. Counters in the sensor pixels mix the detected signals with local oscillators to down-convert the signal of interest, e.g., to a baseband frequency. The counters store the down-converted signal for read out at a rate lower than the Nyquist rate of AM signal. The counts can be shifted among pixels synchronously with the optical line-of-sight for scanning operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.