Journal ArticleDOI
Automatic adjustment of quadrature modulators
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TLDR
In this article, a diode detector is used to provide amplitude feedback to guide the adaption of baseband circuits that correct for carrier leak, differential gain and phase mismatch errors.Abstract:
A technique for the automatic correction of errors in RF quadrature modulators is described. The method uses a diode detector to provide amplitude feedback to guide the adaption of baseband circuits that correct for carrier leak, differential gain and phase mismatch errors.read more
Citations
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Journal ArticleDOI
Adaptive compensation for imbalance and offset losses in direct conversion transceivers
James K. Cavers,M.W. Liao +1 more
TL;DR: This paper focuses on the three principal impairments of analog quadrature modulators and demodulators: gain imbalance, phase imbalance, and DC offset.
Journal ArticleDOI
Adaptive linearization using predistortion-experimental results
TL;DR: An adaptive predistortion system to linearize class B and class C radio frequency high power amplifiers using a digital signal processing microprocessor and memory look-up tables to predistort the baseband drive signals.
Journal ArticleDOI
Frequency-Selective I/Q Mismatch Calibration of Wideband Direct-Conversion Transmitters
TL;DR: This brief focuses on digital-signal-processor-based I/Q mismatch calibration in wideband direct-conversion transmitters, assuming the challenging case of frequency-dependent I/ Q mismatch, and proposes two alternative principles for calibration parameter estimation.
Adaptive Linearization Using Predis tortion-Experiment a1 Results
Michael Faulkner,Mats Johansson +1 more
TL;DR: In this paper, an adaptive predistortion system was proposed to linearize class B and class C radio frequency high power amplifiers. But the system is limited to a 30 dB power control range.
Proceedings ArticleDOI
Adaptive compensation for imbalance and offset losses in direct conversion transceivers
James K. Cavers,M.W. Liao +1 more
TL;DR: It is demonstrated that the LMS (least mean square) algorithm can be used to adapt the compensator in a manner similar to an equalizer, and that the computational load is the same as that of a three-tap equalizer.
References
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Journal ArticleDOI
Analysis of quadrature detectors using complex envelope notation
TL;DR: In this paper, the relationship between complex envelope notation and quadrature detection is discussed, and there follows an analysis of quadratures demodulation including the effects of gain mismatch, phase error, local oscillator breakthrough and DC offsets.
Journal ArticleDOI
Error Analysis of a Quadrature Coherent Detector Processor
TL;DR: In this article, a simple method for computing the output signal distortion resulting from relative phase and gain errors between the two quadrature detector channels of a baseband processing system is presented.
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Adaptive compensation for imbalance and offset losses in direct conversion transceivers
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