Flexible and programmable delta-sigma analog signal converter
US5952947A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1997 |
| Grant date | Sep 14, 1999 |
| Priority date | — |
| Expiry date | Sep 9, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/458
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Processing apparatus is provided that directly samples and quantizes a complex envelope of a bandlimited waveform centered at a predetermined carrier frequency. An oversampling delta-sigma modulator 1 samples and quantizes the input signal to a single bit data stream. A serial-to-parallel converter converts the single bit data stream into a parallel bit stream. A digital decimation filter digitally filters the parallel bit stream to produce an estimate of the baseband in-phase and quadrature components of the input signal. In-phase and quadrature video filters generate in-phase and quadrature samples that are output from the analog signal converter. A controller 26 and a plurality of digital-to-analog converters 25 are used to center noise shaping nulls of the delta-sigma modulator around the carrier frequency. The controller sets the spacing between nulls of the serial-to-parallel converter to maximize the signal-to-noise ratio of the analog signal. The controller controls the decimation filter to set the sample times of thereof to sample the carrier in quadrature so that the coefficients are programmed to form a bandpass filter at the carrier frequency and programs the coefficien…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.