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. 04, 2014
Filed:
Apr. 23, 2010
Roland Grozinger, Heitersheim, DE;
Arnd Kempa, Steinen, DE;
Roland Grozinger, Heitersheim, DE;
Arnd Kempa, Steinen, DE;
Endress + Hauser GmbH + Co. KG, Maulburg, DE;
Abstract
A low noise analog filter with adjustable filter frequency includes an oscillatory circuit, whose resonance frequency equals the filter frequency of the filter. The oscillatory circuit has a first circuit branch. One of the frequency determining elements is a capacitance and the other an inductance. The low noise analog filter further includes an amplifier with adjustable amplification installed in one of the two circuit branches. The output of the amplifier is connected with its inverting input via the frequency determining element arranged in such circuit branch. In filter operation, the amplifier amplifies, according to the adjusted amplification, a voltage applied across the frequency determining element arranged in such circuit branch and thereby effects a corresponding change of an electrical current flowing through such frequency determining element.