Carrier buffer having current-controlled tracking filter for spurious signal suppression
US5736903A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 1996 |
| Grant date | Apr 7, 1998 |
| Priority date | — |
| Expiry date | Apr 24, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/099
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Spurious energy suppression for a data communication system is achieved without using a large order noise suppression filter, by means of a pre-mixer tracking filter incorporated into an emitter-coupled logic configured buffer of a carrier frequency generator, using a MOSFET-implemented current-controlled resistance component of a resistor-capacitor network and an associated current control stage. The MOSFET-implemented resistance components of the filter are controlled by the same control current that establishes the carrier generator's output frequency. As a result, the cut-off frequency of the tracking filter is linearly proportional to the carrier and effectively independent of process parameters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.