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. 26, 2013
Filed:
Mar. 10, 2010
Drew A. Hall, Stanford, CA (US);
Richard Gaster, Los Altos, CA (US);
Sebastian J. Osterfeld, Mountain View, CA (US);
Shan X. Wang, Portola Valley, CA (US);
Drew A. Hall, Stanford, CA (US);
Richard Gaster, Los Altos, CA (US);
Sebastian J. Osterfeld, Mountain View, CA (US);
Shan X. Wang, Portola Valley, CA (US);
The Board of Trustees of the Leland Stanford Junior University, Palo Alto, CA (US);
Abstract
Double modulation of a magnetoresistive sensor entails modulating both an excitation (e.g., voltage or current) applied to the sensor and a tickling magnetic field applied to the sensor. The excitation and magnetic field are modulated at different frequencies fand f, respectively. As a result of the double modulation, the sensor output spectrum includes a carrier tone (CT) at frequency fand side tones (STs) at frequencies f±f. A baseline relation between CT amplitude and ST amplitude is determined (e.g., by measuring CT and ST amplitude while drift occurs in the absence of a sample). During sensor operation, raw ST measurements are corrected using corresponding raw CT measurements to provide corrected ST measurements as the sensor output.