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:
Mar. 14, 2000
Filed:
Nov. 04, 1997
Applicant:
Inventor:
William Kung, Nepean, CA;
Assignee:
Nortel Networks Corporation, Montreal, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
327359 ; 327356 ; 327563 ; 455333 ;
Abstract
In a tree mixer having an input differential pair of transistors as a gain stage and two differential pairs of transistors (transistor quad) as a mixing stage, a further transistor quad in the mixing stage is provided. The further transistor quad is complementary with respect to the first transistor quad. A DC offset is applied between respective mixing inputs of the two transistor quads and the local oscillator input signal is applied to both inputs. The two transistor quads are interconnected through summing circuits such as current mirrors. By appropriately setting the DC offset the mixer can be operated in class A, B or AB as desired.