Analog Devices,inc.

Analog Devices International Unlimited Company

Brian Reggiannini

Antonio J Montalvo

Christopher Mayer

Wei An

Richard P Schubert

David J Mclaurin

Jianxun Fan

Lu Wu

Tolga Pamir

Aleksey Kagan

Ahmed Ali

Hatice Ozis Unsal

Richard Schubert

Gordon Allen

A method of operating a radio frequency (RF) transceiver includes transmitting a narrowband calibration signal using a transmit channel of the RF transceiver, wherein a transmitted output signal includes a sideband of the calibration signal and a sideband of a digital-to-analog converter (DAC) image signal produced by DAC circuitry of the transmit channel; sampling the transmitted output signal using an analog-to-digital converter (ADC) circuit; filtering the transmitted output signal sampled by the ADC circuit to reduce power of the sideband of the calibration signal; attenuating DAC signals produced by the DAC circuitry to reduce power of the sideband of the DAC image signal; restoring the power of the sideband of the calibration signal sampled by the ADC circuit; and performing quadrature error correction (QEC) using the output of the ADC circuit.

Calibration of DAC images for improved transmit quadrature error correction

A receiver apparatus models and corrects the frequency-dependent and the frequency-independent mismatches between I and Q paths jointly by polynomial estimations. The receiver apparatus may sample digitized I and Q path signals. The sampled data point may be modeled in equations with real and imaginary components. The sampled discrete time-domain data may be converted to frequency-domain data. Multiple statistics values based on the frequency-domain data may be computed. Coefficients for the polynomial equations may be estimated based on the computed statistic values. The channel mismatches may be estimated from the polynomial equations and used to compensate the mismatch either on the I path or the Q path.

Real-time I/Q imbalance correction for wide-band RF receiver

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Norwood, MA, United States of America

Brian Reggiannini