Wideband fast-hopping receiver front-end and mixing method
US6693980B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 2000 |
| Grant date | Feb 17, 2004 |
| Priority date | — |
| Expiry date | Feb 26, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D7/165
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A wideband fast-hopping receiver front-end uses direct digital synthesis (DDS) to provide quadrature LO signals to the front-end's mixers. A DDS circuit stores multiple digital word sequences which represent desired waveforms, and outputs desired sequence pairs to a pair of DACs in response to a clock signal and a command signal. The DACs convert the sequences to analog signals, which are filtered and squared as necessary to provide quadrature LO signals to the mixers. Frequency hopping is accomplished by changing the command signal, which causes a different pair of sequences to be output and the frequency of the LO signals provided to the mixers to be changed. Active image rejection is combined with DDS LO generation to provide faster frequency hopping. The front-end is combined with an ADC and a communications signal processor to provide a complete system, all of which can be integrated together on a common substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.