The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 10, 2010
Filed:
Sep. 21, 2006
Roger W. Van Brunt, Santa Cruz, CA (US);
Mark Alexander John Moffat, Mortimer, GB;
Steve Picken, Santa Cruz, CA (US);
Roger W. Van Brunt, Santa Cruz, CA (US);
Mark Alexander John Moffat, Mortimer, GB;
Steve Picken, Santa Cruz, CA (US);
RF Micro Devices, Inc., Greensboro, NC (US);
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.