Continuous reversible gear shifting mechanism
US7498890B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 2006 |
| Grant date | Mar 3, 2009 |
| Priority date | — |
| Expiry date | Mar 8, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/1806
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A novel gear shifting mechanism operative to adjust the loop gain of a phase locked loop (PLL) circuit in a continuous and reversible manner. The loop gain can be increased to widen the bandwidth of the loop and can also be decreased to narrow the loop bandwidth. The mechanism incorporates an α gear shift circuit, a ρ gear shift circuit and an optional IIR gear shift circuit. The α gear shift circuit comprises a infinite impulse response (IIR) filtering which enables hitless operation of the PLL loop at the occurrence of gear shift events. The α gear shift circuit comprises an accumulator whose output is multiplied by the gain value ρ. The invention enables multiple gear shifts in either positive or negative direction to be achieved by configuring the loop gain variables α and ρ which may be accomplished in software.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.