Filter circuit with a resonator operated in series resonance

US5530391A · kind A · utility

Assignee

• Temic Telefunken Microelectronik · DE

Inventors

• Rolf Bohme · Midrand, ZA
• Johann Burkhart · Brackenheim, DE
• Johann Traub · Lauingen, DE
• Konrad Hirsch · Blaustein, DE

Key dates

• Filing date: Mar 2, 1994
• Grant date: Jun 25, 1996
• Expiry date: Mar 2, 2014

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03H11/1208
• WIPO field: Basic communication processes
• WIPO sector: Electrical engineering

Abstract

A filter that has a resonator operated in series resonance and a two-pole terminal resonator circuit with a resonator whose electric conductance can be divided into a useful component and a parasitic component. A first differential stage actuated by a signal source and having two active elements whose ground connections are each linked to a respective current source and to a respective connection of the two-terminal resonator. A compensation circuit having two connections and which simulates the parasitic component of the resonator electric conductance is connected to a second differential stage which actuated by the signal source, is of the same type as the first differential stage, and has two active elements whose ground connections are each linked to a respective current source and to a respective connection of the compensation circuit. An evaluation circuit is linked to the two mutually reversed, i.e. connected in phase opposition, output connections of the two differential stages.