Delta-sigma digital radiometric system
US9983304B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 2015 |
| Grant date | May 29, 2018 |
| Priority date | — |
| Expiry date | Sep 25, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/365
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A passive radiometric system for thermally imaging objects in a scene. The system includes a digital square-law quantizer circuit including a plurality of comparators and a voltage divider network having a plurality of resistors. Each comparator receives a different reference signal generated by the voltage divider network and a common power signal from an antenna and outputs a high or low digital bit signal. The system also includes a delta-sigma circuit having a weighting table responsive to the digital bit signals from the comparators that converts the digital bit signals to a normalized bit word. The delta-sigma circuit also includes an accumulator that receives the digital bit words from the weighting table and provides an average of the digital bit words. The system also includes a digital-to-analog converter that converts the averaged bit words to an analog signal that is provided as a feedback signal to the quantizer circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.