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. 03, 1990
Filed:
May. 17, 1988
Heinz B Mader, Brutten, CH;
Telefonaktiebolaget L M Ericsson, Stockholm, SE;
Abstract
The invention can be related to the technical field of implementation and control of electricity controllable active fibers. In accordance with the invention filters are controlled and implemented with the aid of a differential gain stage. Said stage includes pairs of like amplification components (Q.sub.I11 and Q.sub.I21, Q.sub.I12 and Q.sub.I22, Q.sub.I13 and Q.sub.I23), and groups of series-connected diode components as well as at least one current generator (Q1, Q2, Q3). The forward voltage drop of the diode components has the same current responsiveness as the base-emitter voltage of the amplification components. A filter of the first order includes a differential gain stage with a capacitive component (C) connected across the output of said stage or to its amplification components. A filter of the second order can include two differential gain stages, each with its capacitive component (C1, C2) in circuit. An oscillator for controlling filters can comprise three series-connected lowpass filters each including its differential gain stage.