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. 17, 1976
Filed:
Jun. 20, 1975
Pierre Thepaut, Lannion, FR;
Lignes Telegraphiques et Telephoniques, Paris, FR;
Abstract
Active filter cells comprising dipoles formed by means of capacitors and resistors having a pair of input terminals and a pair of output terminals, with, in each pair, a grounded first terminal and a non-grounded second terminal. They comprise two elementary networks each of which including: an operational amplifier having first and second inputs, the first of which is connected to a reference potential, and an output; a first dipole connected between said second input terminal of the cell and said second input of said amplifier; a second dipole connected between said second input and said output of said amplifier; and a third dipole connecting said output of said amplifier to said second output terminal of the cell. At least one of said networks contains a fourth dipole connected by one of its terminals to said second input of one of said amplifiers and by its other terminal to said second output terminal of the cell. The above-described arrangement can be combined with a third amplifier, of the differential type, whose output constitutes the output of the cell.