Band-pass filter having a ring resonator

US7944327B2 · kind B2 · utility

Assignee

• EPCOS AG · DE

Inventors

• Roman Kravchenko · Graz, AT
• Denys Orlenko · Munich, DE
• Georgiy Sevskiy · Munich, DE
• Patric Heide · Vaterstetten, DE

Key dates

• Filing date: Sep 26, 2006
• Grant date: May 17, 2011
• Expiry date: Nov 15, 2027

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03H2001/0085
• WIPO field: Basic communication processes
• WIPO sector: Electrical engineering

Abstract

A bandpass filter is described herein. The bandpass filter has two parallel signal branches, each connected, on an input side, to an input node and, on an output side, to an output node. The two signal branches form a ring resonator, having a wave mode with a complex amplitude of {right arrow over (U)}CW=|{right arrow over (U)}CW|exp{−jφCW} propagating in a clockwise direction and a wave mode with a complex amplitude of {right arrow over (U)}CCW=|{right arrow over (U)}CCW|exp{−jφCCW} propagating in a counterclockwise direction. The vector sum of a resulting wave {right arrow over (U)}out at the output node of the bandpass filter at two or more stop frequencies is: {right arrow over (U)}out={right arrow over (U)}CW+{right arrow over (U)}CCW=0, and |{right arrow over (U)}CW|=|{right arrow over (U)}CCW| and |φCW−φCCW|=180°. The stop frequencies are arranged such that a passband is formed between two stop frequencies.