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:
Apr. 12, 1977
Filed:
Jul. 31, 1975
Jean-Paul Bonnefoy-Claudet, St-Martin d'Heres, FR;
Michel Martin, Eybens, FR;
Edmond Tournier, Grenoble, FR;
Commissariat a l'Energie Atomique, Paris, FR;
Abstract
In the synchronous detection signals of frequency Fo immersed in a noise, an auxiliary signal is produced having a period 1/2 Fo and in the form of a rectified symmetrical wave, by rectifying a symmetrical wave of period 1/Fo. The signal to be filtered is multiplied by the auxiliary signal and synchronous filtering or synchronous detection on the frequency Fo is performed on the signal obtained after the above-mentioned multiplication. Preferably the auxiliary signal is produced in the form of a rectified sinusoidal wave and a square wave reference signal from which the above-mentioned symmetrical wave is derived, having the period 1/Fo, is also used to control the synchronous detection or the synchronous filtering.