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:
Oct. 19, 2004
Filed:
Oct. 17, 2000
Behzad Razavi, Los Angeles, CA (US);
Pengfei Zhang, Fremont, CA (US);
RF Micro Devices, Inc., Greensboro, NC (US);
Abstract
In accordance with embodiments of the present invention, a receiver system is provided with a variable gain mixer circuit that is advantageous over current architectures used in wireless communication systems. The use of a variable gain mixer circuit simplifies the receiver architecture resulting in the elimination of additional circuit blocks and a reduction in complexity and cost. Moreover, one embodiment of the present invention includes a mixer circuit comprising a mixer core, a bias circuit coupled to the mixer core for providing a bias current, and a variable impedance network. The mixer core receives input signals and generates output currents that are coupled to the variable impedance network. Each of the output currents are selectively coupled to a voltage output node through a variable impedance. Variable gain is established by varying the impedance between the output currents of the mixer core and the voltage output node.