Calibrated quadrature very low intermediate frequency receiver
US7773965B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 2006 |
| Grant date | Aug 10, 2010 |
| Priority date | — |
| Expiry date | May 10, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D1/2245
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present invention is a quadrature VLIF receiver, including calibration circuitry, and methods to closely match signal processing of an in-phase signal path and a quadrature-phase signal path to optimize VLIF image rejection. The calibration circuitry includes a variable gain variable-phase calibration signal generator, a variable gain amplifier for each signal path, phase adjustment circuitry for each signal path, and switching circuitry to support calibration steps. The calibration signal generator supplies a calibration signal at the same frequency as mixer local oscillator signals; therefore, during calibration, all signals downstream of the VLIF mixer are at DC, which simplifies calibration measurements, thereby minimizing calibration times.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.