Frequency-selective quadrature baseband coupling cancellation
AssigneeIntel IP Corporation
InventorOren E. Avraham
Life of this patent
Estimating the term…
Abstract
Described herein are architectures, platforms and methods for implementing cancellation of asymmetric quadrature gain imbalance due to frequency selective quadrature baseband coupling in a transceiver of device. Radio frequency (RF) are converted to quadrature baseband signals, estimation is made as to coupling between in-phase (I) and quadrature-phase (Q) channels of the quadrature baseband signals. The quadrature baseband signals are converted into digital baseband signals, and digital compensation is applied on the digital baseband signal based on the estimated amount of coupling.
Claims20
A method of frequency-selective quadrature baseband coupling cancellation, the method comprising:
- receiving and converting radio frequency (RF) signals into quadrature baseband signals;
- measuring a coupling factor by injecting a single tone and disabling at least one of an in-phase (I) channel or a quadrature-phase (Q) channel of the quadrature baseband signals, wherein a capacitive or an inductive coupling across the I and Q channels comprises a negative capacitance value;
- converting the quadrature baseband signals into digital I and Q baseband signals;
- measuring a ratio between the digital I and Q baseband signals;
- and
- applying a digital compensation on the digital I and Q baseband signals based on the measured amount of coupling factor.
A device comprising:
- an antenna array configured to receive radio frequency (RF) signals;
- at least one mixer configured to transform the received RF signals into quadrature RF signals;
- at least one low-pass filter (LPF) configured to transform the quadrature RF signals into in-phase (I) and quadrature-phase (Q) baseband signals;
- a coupling detector configured to estimate an amount of coupling by injecting a single tone and disabling an I channel or Q channel that passes the I and Q baseband signals, respectively, wherein coupling detector measures a ratio of the I and Q baseband signals after conversion into digital baseband signals, wherein a capacitive or an inductive coupling across the I and Q channels comprises a negative capacitance value;
- an analog-to-digital converter (ADC) configured to convert the I and Q baseband signals into the digital baseband signals;
- and
- a digital compensator configured to apply a digital compensation on the digital baseband signal based on the estimated amount of coupling.
A transceiver circuitry comprising:
- a first block, which is configured to receive and convert radio frequency (RF) signals into quadrature baseband signals;
- a second block that is configured to:
- estimate an amount of coupling between in-phase (I) and quadrature-phase (Q) channels of the quadrature baseband signals by injecting a single tone, disabling at least one of the I channel or the Q channel, and measuring a ratio at an output of an analog to digital converter (ADC);
- and
- apply a compensation in response to the estimated amount of coupling, wherein the applied compensation cancels a generated asymmetric quadrature gain imbalance.
Dependencies are inferred from the claim text.