Parallel accumulator fractional-n frequency synthesizer
US5777521A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 1997 |
| Grant date | Jul 7, 1998 |
| Priority date | — |
| Expiry date | Aug 12, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/1976
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A frequency synthesizer (10) including a synthesizer loop (12) with a fractional-N divider (14), and including a divider control circuit (18) and a combining circuit (22). The divider control circuit (18) provides a variable divide value (20) to the divider (14). The carry values of two accumulators (24, 26) having differing accumulator lengths are applied in parallel to the combining circuit (22). Each of the accumulators (24, 26) provides a portion of a desired fractional divide value (20). The combining circuit (22) also adds an integer divide value (36) to the fractional divide value (16). By coupling the accumulators (24, 26) in parallel, a high frequency resolution with minimal spurious frequencies is achieved, using a simple, low cost circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.