Freescale Semiconductor,inc.

Jiangbo Gan

Brandt Braswell

Pravin Premakanthan

Michael L Gomez

Gerald P Miaille

Christian J Rotchford

Boris Razmyslovitch

Srinivasa R Bommareddy

A gain control process () executed at a transmitter () generates () a gain ramp signal () having a delay component () and a gain component (). The process () further generates () and incorporates () a gain arc () into a digital signal to form a digital gain signal () having a digital gain change (). A combiner () combines a digital input signal () with the digital gain signal () to generate a pre-compensated digital signal (). A variable gain amplifier () applies a sequence of gains () in the gain component () of the gain ramp signal () to a pre-adjusted analog signal () in order to generate a gain-adjusted analog signal (). Application of the gain component () and the digital gain change () occurs when a portion () of the gain arc () indicates a low instantaneous signal power at an antenna () in order to reduce ACLR degradation.

Gain control methods for wireless devices and transmitters

Methods and corresponding systems for calibrating a digital-to-analog converter include selecting first and second code regions in the digital-to-analog converter, wherein the first and second code regions are separated by a boundary. Thereafter a waveform sequence is input into the digital-to-analog converter, wherein the waveform sequence has a zero offset at the boundary. Then a relative compensation value between the first and second code regions is adjusted to reduce a distortion in an output of the digital-to-analog converter. A magnitude of a third harmonic distortion of the waveform sequence can be used to measure distortion in the output. Adjusting the relative compensation can include converting the output of the digital-to-analog converter to a digital sequence, filtering the digital sequence, and measuring a harmonic distortion in the digital sequence.

Calibrating a digital-to-analog converter

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Gilbert, AZ, United States of America

Jiangbo Gan