Global Patent Index - EP 1050141 A2

EP 1050141 A2 2000-11-08 - A METHOD AND A CIRCUIT FOR AM DEMODULATION

Title (en)

A METHOD AND A CIRCUIT FOR AM DEMODULATION

Title (de)

VERFAHREN UND SCHALTUNG ZUM DEMODULIEREN VON AM-SIGNALEN

Title (fr)

PROCEDE ET CIRCUIT DE DEMODULATION AM

Publication

EP 1050141 A2 (EN)

Application

EP 99903597 A

Priority

  • DK 9900076 W
  • DK 24798 A

Abstract (en)

[origin: WO9943132A2] The invention relates to a method for simultaneous AM demodulation of data which are transferred between a transponder and an interrogator in connection with metal detection. The carrier wave signal is amplitude modulated by the information signal and is fed to an input of a receiver where it is branched into two parts, so that the first part is fed to a severe limiter, while the second part is fed to a first input of a mixer whose second input receives the output signal from the severe limiter. The two signal parts are multiplied in the mixer. A DC signal used for metal detection and an AC signal used for determining a possible information signal occur on the output of the mixer. The AM signal is fed to the receiver from an antenna which contains an adjusted circuit, which receives a signal galvanically separated from a generator. Signals from objects which partly contain a tag with identification data and partly do not contain a tag, may be used for detection and identification of objects.

IPC 1-7 (main, further and additional classification)

H04L 27/06; G01V 3/10

IPC 8 full level (invention and additional information)

H03D 1/00 (2006.01); H04B 1/59 (2006.01); H04L 27/06 (2006.01)

CPC (invention and additional information)

H04L 27/06 (2013.01)

Citation (search report)

See references of WO 9943132A3

Designated contracting state (EPC)

DE DK FR GB IT

EPO simple patent family

WO 9943132 A2 19990826; WO 9943132 A3 19991028; AU 2412199 A 19990906; BR 9908174 A 20001031; CA 2320699 A1 19990826; CN 1292189 A 20010418; DK 24798 A 19980303; EP 1050141 A2 20001108; JP 2003527754 A 20030916

INPADOC legal status


2004-03-31 [18D] DEEMED TO BE WITHDRAWN

- Effective date: 20030802

2000-11-08 [17P] REQUEST FOR EXAMINATION FILED

- Effective date: 20000814

2000-11-08 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A2

- Designated State(s): DE DK FR GB IT