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:
Dec. 07, 1999
Filed:
Jun. 30, 1998
Keng Leong Fong, Sunnyvale, CA (US);
Philips Electronics North Amercia Corporation, New York, NY (US);
Abstract
A circuit includes a transconductance device which converts an input signal voltage to a signal current. An output terminal is coupled to receive signal current from the transconductance device. A gain-control circuit has an impedance network coupled to the output terminal to maintain a constant impedance at the output terminal and selectively steers current from the transconductance device through at least first and second different nodes of the impedance network to vary the current supplied to the output terminal. The circuit has reduced noise figure degradation as compared to known current steering circuits by controlling gain without dumping signal current directly to the supply and without changing the impedance at the output terminal. The circuit is particularly useful in the RF section of radio receivers and transmitters, such as in cellular phones.