Multiphase receiver and oscillator

The present invention relates to radio transmitters and receivers, and to oscillators for use therein. In particular, the present invention, in its various aspects, addresses problems that arise in connection with designing and fabricating radio circuits on integrated circuit chips, and particularly...

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Bibliographic Details
Main Authors Vu, Hoai Xuan, Vu, Toan Xuan
Format Patent
LanguageEnglish
Published 07.05.2002
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Summary:The present invention relates to radio transmitters and receivers, and to oscillators for use therein. In particular, the present invention, in its various aspects, addresses problems that arise in connection with designing and fabricating radio circuits on integrated circuit chips, and particularly on CMOS integrated circuit chips. A differential ring oscillator is provided with three differential amplifiers and provides three-phase output signals which can be used for synchronous detection of a received multi-phase modulated signal in a multi-phase receiver, wherein the phase of the local oscillator signals may be in other-than-quadrature relation. Two of the phase outputs of the local oscillator can be combined to provide a signal that is in quadrature with the remaining output. The oscillator is preferably controlled in coarse frequency control steps and using a fine voltage control signal responsive to a phase-locked loop to reduce frequency modulation of the oscillator signal arising out of leakage signals.