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1. WO1996003805 - IMPROVEMENTS IN OR RELATING TO ZERO IF RECEIVERS

Publication Number WO/1996/003805
Publication Date 08.02.1996
International Application No. PCT/IB1995/000474
International Filing Date 13.06.1995
IPC
H03G 3/20 2006.01
HELECTRICITY
03BASIC ELECTRONIC CIRCUITRY
GCONTROL OF AMPLIFICATION
3Gain control in amplifiers or frequency changers
20Automatic control
CPC
H03G 3/3052
HELECTRICITY
03BASIC ELECTRONIC CIRCUITRY
GCONTROL OF AMPLIFICATION
3Gain control in amplifiers or frequency changers ; without distortion of the input signal
20Automatic control
30in amplifiers having semiconductor devices
3052in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver
Applicants
  • PHILIPS ELECTRONICS N.V. [NL/NL]; Groenewoudseweg 1 NL-5621 BA Eindhoven, NL
  • PHILIPS NORDEN AB [SE/SE]; Kottbygatan 5, Kista S-164 85 Stockholm, SE (SE)
  • PHILIPS ELECTRONICS UK LIMITED [GB/GB]; 420-430 London Road Croydon CR9 3QR, GB (GB)
Inventors
  • CUSDIN, Anthony, Richard; GB
  • DAVIE, Alan, James; GB
  • MOORE, Paul, Anthony; GB
Agents
  • MOODY, Colin, James; Internationaal Octrooibureau B.V. P.O. Box 220 NL-5600 AE Eindhoven, NL
Priority Data
9415120.627.07.1994GB
Publication Language English (EN)
Filing Language English (EN)
Designated States
Title
(EN) IMPROVEMENTS IN OR RELATING TO ZERO IF RECEIVERS
(FR) AMELIORATIONS CONCERNANT DES RECEPTEURS SANS FREQUENCES INTERMEDIAIRES
Abstract
(EN)
An automatic gain control strategy for zero IF receivers in which the gain of low pass filters (20, 22) is altered whilst keeping their bandwidths substantially constant. The low pass filters (20, 22) are implemented as gyrator filters, each of which comprises at least one pair of transconductors, the ratio of the transconductances of which are adjustable in such a manner as to maintain the product of their transconductances constant. An electronic signal for adjusting the ratio of the transconductances is derived from an estimate of the instantaneous signal amplitude of the received signal.
(FR)
L'invention concerne une stratégie de commande automatique de gain pour des récepteurs sans fréquences intermédiaires dans laquelle le gain de filtres passe-bas (20, 22) est modifié pendant que l'on maintient leurs largeurs de bande sensiblement constantes. Les filtres passe-bas (20, 22) sont mis en ÷uvre sous forme de filtres gyrateurs, chacun d'entre eux comprenant au moins une paire de transconducteurs, dont les rapports des transconductances sont ajustables de manière à maintenir le produit de leurs transconductances constant. Un signal électronique pour ajuster le rapport des transconductances est obtenu à partir d'une estimation de l'amplitude instantanée du signal reçu.
Also published as
Latest bibliographic data on file with the International Bureau