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. 28, 2007
Filed:
Oct. 15, 2003
Tajinder Manku, Waterloo, CA;
Tajinder Manku, Waterloo, CA;
Sirific Wireless Corporation, Waterloo, Ontario, CA;
Abstract
The present invention relates generally to communications, and more specifically to a method and apparatus for minimizing DC offset and second-order modulation products (IM2 noise) while demodulating RF signals. The principle of the invention can be applied to differential, down-conversion circuits () consisting of two differential mixers () in series, a follows: a pair of current sources Ia and Ib are used to provide current to positive and negative channels of the first differential mixer (). Providing current to the amplifying transistors of the first mixer () reduces the current drawn through the active mixer switches, reducing the noise generated. The current sourcesandare trimmed in a complementary manner whereI+Delta, and=Delta. The value of Δcan be determined in a number of manners; for example, it could be established by testing after the circuit has been fabricated, and the value stored on-chip, for future use.