Filter circuit arrangement

US7890070B2 · kind B2 · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Jan Bollenbeck · Eggolsheim, DE
• Ralph Oppelt · Uttenreuth, DE

Key dates

• Filing date: Nov 9, 2007
• Grant date: Feb 15, 2011
• Expiry date: Sep 25, 2029

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03H11/1291
• WIPO field: Basic communication processes
• WIPO sector: Electrical engineering

Abstract

A filter circuit arrangement for filtering of a radio-frequency signal has a first tunable filter and a phase regulation loop in order to hold the first tunable filter to a transmission phase constant relative to the frequency of the radio-frequency signal. The filter circuit arrangement has a second tunable filter arranged parallel to the first tunable filter in the phase regulation loop. The first tunable filter and the second tunable filter exhibit different attenuation characteristics and are fashioned and connected within the phase regulation loop so that: a capture range of the filter circuit arrangement, in which a tuning of the phase regulation loop to a radio-frequency signal to be filtered is possible is dominated by the attenuation characteristic of the second tunable filter, and so that the transmission behavior of the filter circuit arrangement in operation is dominated by the attenuation characteristic of the first tunable filter, given a tuned phase regulation loop. A circuit arrangement for generation of a local oscillator signal has an oscillation generator and a filter circuit arrangement as described above arranged downstream of the oscillation generator.