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:
Feb. 16, 2010
Filed:
Jul. 29, 2005
Erik Anderson, San Francisco, CA (US);
Daniel Babitch, San Jose, CA (US);
Majid Hashemi, San Jose, CA (US);
Erik Anderson, San Francisco, CA (US);
Daniel Babitch, San Jose, CA (US);
Majid Hashemi, San Jose, CA (US);
SiRF Technology, Inc., San Jose, CA (US);
Abstract
A radio frequency integrated circuit for a global positioning system (GPS) application mixes radio frequency GPS signals from an external source with a predetermined intermediate frequency that is less than 4f. In one embodiment, the intermediate frequency is selected to be 1.5f. An intermediate frequency filter then band-limits the intermediate frequency GPS signals, rolling off at a frequency in the vicinity of 2.5 MHz to achieve substantial attenuation at 3.5-4.0 MHz. An automatic gain control circuit amplifies the filtered intermediate frequency GPS signals to proper voltage levels. The amplified intermediate frequency GPS signals is then digitized by an analog-to-digital converter at a predetermined sampling rate more than twice the intermediate frequency to provide samples of a predetermined number of bits, which are then provided for base band processing by a general purpose microprocessor over an industry-standard serial bus.