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1. (WO2003075474) SUPERHETERODYNE CIRCUIT WITH BAND-PASS FILTER FOR CHANNEL SELECTION

Pub. No.:    WO/2003/075474    International Application No.:    PCT/FR2003/000586
Publication Date: Sep 12, 2003 International Filing Date: Feb 21, 2003
IPC: H03J 7/02
H04B 1/28
Applicants: CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE (C.N.R.S.)
KAISER, Andreas
BILLOINT, Olivier
GALAYKO, Dimitri Yurievitch
LEGRAND, Bernard
Inventors: KAISER, Andreas
BILLOINT, Olivier
GALAYKO, Dimitri Yurievitch
LEGRAND, Bernard
Title: SUPERHETERODYNE CIRCUIT WITH BAND-PASS FILTER FOR CHANNEL SELECTION
Abstract:
The invention concerns a superheterodyne circuit comprising at least one reception input (5), at least one production output (6) wherefrom can be produced a baseband signal and at least one band-pass filter (8) for channel selection interposed in the signal path (7) between the input (5) and the output (6). The invention is characterized in that the filter (8) is adapted to be connected to means (38) for measuring a characteristic frequency of signal passage in said filter (8), controllable means (22, 23) for frequency shift are arranged in the signal path (7), and control means (40) are provided, connected to the measuring means (38) and controlling the means (22, 23) with a supplementary signal, which compensates the difference of the measured characteristic frequency relative to a prescribed characteristic frequency value of the filter passage (8) and whereof the frequency is determined based on the position of said path (7) of the shifting means (22, 23) relative to the filter (8).