Patent · US Expired

Radio receiver adjacent-channel interference suppression circuit

US5339455A · kind A · utility

76Cited by

9References

4Claims

0Family size

Assignee

Blaupunkt-Werke GmbH · DE

Inventors

Lothar Vogt · Hohenhameln, DE
Stefan Bartels · Bienenbüttel, DE
Rainer Arnold · Obertshausen, DE
Detlef Schwarz · Hannover, DE

Key dates

Filing date	Feb 23, 1993
Grant date	Aug 16, 1994
Priority date	—
Expiry date	Feb 23, 2013

Classification

Technology area (CPC H)Electricity
CPC primaryH04B2001/1054
WIPO fieldTelecommunications
WIPO sectorElectrical engineering

Abstract

A mobile radio receiver, for example, a car radio, needs a circuit to detect and suppress adjacent-channel interference. This can be done by using bandpass filters (14) of differing bandwidth. The present invention dynamically adjusts bandwidth to an optimum value by continuously comparing (13) a first signal level, upstream of the bandpass filter, to a second signal level, downstream of the bandpass filter, to derive a difference value representative of adjacent-channel interference, then uses an electronically controlled selector switch (6) to select a particular filter (14.sub.N) whose bandwidth is sufficiently narrow to cut out the interfering broadcast signal. A table associating each magnitude range of interference with a particular filter bandwidth assures that bandwidth is broadened as interference diminishes, thereby assuring sufficient reception signal strength.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.