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:
Apr. 19, 2011
Filed:
Mar. 19, 2008
Shawn Sellars, Ottawa, CA;
Jose Macedo, Ottawa, CA;
Shawn Sellars, Ottawa, CA;
Jose Macedo, Ottawa, CA;
Skyworks Solutions, Inc., Woburn, MA (US);
Abstract
Second-order intermodulation distortion can be suppressed in a direct conversion radio receiver having a downconversion mixer by calibrating resistors and a current source in the mixer. A test signal is applied to the signal inputs of the mixer transconductor. The resistances of first and second variable resistor circuits connected to the switching quad are then varied while also varying a variable current source. Each time the resistances and current are set to new values, the resulting mixer output signal is measured. When the measured output signal is determined to be at a minimum, the variable resistors and current source are left at the corresponding values to which they have been set. Adjusted in this manner, the current source counteracts the DC offset voltage at the mixer output.