Stable in-phase/quadrature (I/Q) generator method and apparatus
US6804306B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 2001 |
| Grant date | Oct 12, 2004 |
| Priority date | — |
| Expiry date | Feb 22, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0016
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method for generating an in-phase (I) output signal and a quadrature-phase (Q) output signal from an input signal reduces phase error in the I/Q generator by delaying-and-doubling an input signal to produce a Q output signal and delaying the input signal twice and subtracting the same from the input signal to produce an I output signal. The I/Q generator includes a first 90°-phase delay circuit receiving an input signal and outputting an intermediate Q signal; a second 90°-phase delay circuit receiving the intermediate Q signal and producing an intermediate I signal. It also includes a signal doubler receiving the intermediate Q signal and producing a Q output signal of twice the amplitude of the input signal at a 90° phase angle. Finally, the generator includes a signal differencer receiving the input signal and the intermediate I signal and producing an I output signal of substantially twice the amplitude of the input signal at a 0° phase angle. The first and second delay circuits need only be substantially matched with one another to render the I/Q generator amplitude and phase stable over a broad range of manufacturing process, operating temperature and input …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.