Global Patent Index - EP 0495921 A4

EP 0495921 A4 19920923 - STABILIZING CIRCUIT FOR FEEDBACK RF AMPLIFIER

Title (en)

STABILIZING CIRCUIT FOR FEEDBACK RF AMPLIFIER

Publication

EP 0495921 A4 19920923 (EN)

Application

EP 90917172 A 19901010

Priority

US 42226789 A 19891016

Abstract (en)

[origin: WO9106149A1] A transmitter (100), with an inphase input (102) for receiving an inphase baseband input signal, and a quadrature input (112) for receiving a quadrature baseband input signal, comprises a modulator (130), coupled to the inphase and quadrature inputs, for modulating the inphase and quadrature baseband signals, to provide a modulated radio-frequency signal, and a linear amplifier (135), coupled to the modulator, for amplifying the modulated radio-frequency signal to produce an output signal. An oscillation detector is coupled to receive the output signal, for detecting oscillation, and for producing an error signal as a result of the oscillation. The transmitter also comprises circuitry (transmission gates 124, 126, 127, and 128) for reducing the open loop gain of the feedback loop, disposed between the inphase and quadrature inputs and the modulator. The circuitry for reducing the open loop gain reduces the open loop gain of the transmitter to less than one, in response to the error signal.

IPC 1-7

H03F 1/26

IPC 8 full level

H03C 3/08 (2006.01); H03F 1/26 (2006.01); H03F 1/32 (2006.01); H03F 1/34 (2006.01); H04L 27/36 (2006.01)

CPC (source: EP)

H03C 3/08 (2013.01); H03F 1/3247 (2013.01); H03F 1/3276 (2013.01); H03F 1/3282 (2013.01); H03F 1/3294 (2013.01); H03F 1/34 (2013.01); H04L 27/368 (2013.01); H03F 2200/102 (2013.01); H03F 2200/336 (2013.01); H03F 2200/57 (2013.01)

Citation (search report)

Designated contracting state (EPC)

AT BE CH DE DK ES FR GB GR IT LI LU NL SE

DOCDB simple family (publication)

WO 9106149 A1 19910502; EP 0495921 A1 19920729; EP 0495921 A4 19920923; JP H05501040 A 19930225

DOCDB simple family (application)

US 9005801 W 19901010; EP 90917172 A 19901010; JP 50037590 A 19901010