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. 07, 2007
Filed:
Sep. 01, 2005
Martin Junkar, San Mateo, CA (US);
Johan Bergerengen, San Francisco, CA (US);
Martin Junkar, San Mateo, CA (US);
Johan Bergerengen, San Francisco, CA (US);
Other;
Abstract
A GPS receiver comprises a crystal oscillator with a manufacturer's characteristic curve, a GPS radio, a TCO temperature sensor, and a GPS receiver software. The crystal oscillator serves as a local reference oscillator for the GPS radio. The GPS receiver software instructs the GPS radio to search radio spectrum for GPS satellite transmissions. Once the combination locks onto a minimum number of GPS satellites and produces a user position fix, the precise crystal oscillator frequency can be measured and associated with a temperature reading from the TCO to software-compensate the local oscillator in later cold-start frequency searches. A 'flat' SCXO model is piecemeal upgraded with individual calibrations as they are collected over the life of the GPS receiver. During manufacturing of the GPS receiver such flat-SCXO model begins as a device characteristic curve supplied by the crystal manufacturer.