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. 16, 1999
Filed:
Nov. 10, 1997
Gerald L Assard, Waterford, CT (US);
Antonio L Deus III, Westerly, RI (US);
Barry A Blakely, Essex, VT (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A demodulation system and method is used in a sensor system, such as a fi optic sensor system, that senses optical signals and modulates a phase generated carrier having a carrier frequency .omega..sub.c to form a modulated carrier. The modulated carrier is preferably undersampled at three times the carrier frequency (3.omega..sub.c), thereby maximizing the sensors' demodulated bandwidth relative to the sensors' sampling frequency. The undersampled, modulated carrier is orthogonally demodulated by multiplying the undersampled, modulated carrier by cos(.omega..sub.c (t.sub.o)) and sin(.omega..sub.c)(t.sub.o)) to extract even and odd harmonic components of the signal of interest. The even and odd harmonic components of the signal of interest are further demodulated by taking the square root of the sum of squares of the even and odd harmonic components, normalizing the even and odd harmonic components, and differentiating, cross-multiplying and differencing the normalized even and odd harmonic components to recover the signal of interest.