Modem having a phase corrector and a voltage controlled oscillator implemented using a multi-stage ring oscillator
US5438301A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 1994 |
| Grant date | Aug 1, 1995 |
| Priority date | — |
| Expiry date | Jul 25, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B27/00
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A carrier generator circuit for use in a modem employed in a wireless communication system is described. The carrier generator circuit includes a voltage controlled oscillator comprising an N-stage ring oscillator to generate N balanced vectors of equal magnitude and arbitrary phase difference. The carrier generator circuit also includes a phase corrector to add two of the balanced vectors to generate a sum vector and to subtract the two balanced vectors to generate a difference vector. The sum vector and difference vector have a phase difference of 90 degrees. The sum vector represents an I (in-phase) carrier signal component and the difference vector represents a Q (quadrature-phase) carrier signal component. These I and Q carrier signal components can be used to transmit and receive data signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.