Wireless communication semiconductor integrated circuit device and mobile communication system
US7423493B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2006 |
| Grant date | Sep 9, 2008 |
| Priority date | — |
| Expiry date | Aug 24, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0891
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An RF IC in which a PLL circuit including a loop filter is incorporated into a semiconductor chip is achieved without increasing power consumption or chip size. The RF IC includes a VCO capable of switching oscillation frequency bands, a variable frequency divider, a phase comparator, and a loop filter, which are contained in the PLL loop. A discrimination circuit discriminates a lead or lag in a phase of an output signal from the variable frequency divider against a reference signal and an automatic band selecting circuit generates a signal for switching the frequency bands of the VCO based on output from the discrimination circuit. While switching the frequency bands of the VCO by means of bisection algorithm, the RF IC detects an optimum frequency band, and adds offset to it to determine a final usable frequency band.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.