RF receiver mismatch calibration system and method
AssigneeSilicon Storage Technology, Inc.
InventorsZhiwei Xu, Shan Jiang, Charles Chien
Life of this patent
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Abstract
A calibration system for an RF system that includes an RF receiver capable of operating in a normal mode and in a calibration mode. The calibration system includes a phase delay unit provided on at least one of an I channel output and a Q channel output of the RF receiver. The system further includes a phase detector configured to detect a phase difference between the I channel output of the RF receiver and the Q channel output of the RF receiver. The system also includes a calibration control unit configured to provide a digital calibration control signal to the RF receiver based on the phase difference as provided by the phase detector.
Claims20
A calibration system for an RF system that includes an rf receiver capable of operating in a normal mode and in a calibration mode, comprising:
- one or more phase/amplitude mismatch calibrating elements integrated with at least one RF receiver component selected from the group composed of a local oscillation buffering circuit, a divide-by-two circuit, and a down conversion mixer;
- a calibrated phase delay unit provided on at least one of an I channel output and a Q channel output of the RF receiver;
- a phase detector configured to detect a phase difference between the I channel output of the RF receiver and the Q channel output of the RF receiver with the calibrated phase delay;
- and
- a calibration control unit configured to provide a calibration control signal to the RF receiver based on the phase difference as provided by the phase detector;
- wherein the calibrated phase delay unit delays one or both of the I channel output and the Q channel output during a calibration mode to make I channel phase equal to Q channel phase.
A method of calibrating an RF receiver, comprising:
- providing a first local oscillation signal to an input of the RF receiver during a calibration mode, as an calibration input signal;
- mixing the calibration input signal with a second local oscillation signal at a same frequency as the first local oscillation signal, and with a third local oscillation signal at a frequency lower than the first and second local oscillation signals;
- delaying at least one of signals on I and Q channel outputs of the RF receiver;
- detecting a phase difference between the delayed, at least one of signals on the I and Q channels;
- and
- providing a calibration signal to the RF receiver based on the detected phase difference.
A calibration system for an RF system that includes an rf receiver capable of operating in a normal mode and in a calibration mode, comprising:
- a phase delay unit provided on at least one of an I channel output and a Q channel output of the RF receiver;
- a phase detector configured to detect a phase difference between the I channel output of the RF receiver and the Q channel output of the RF receiver;
- and
- a calibration control unit configured to provide a calibration control signal to the RF receiver based on the phase difference as provided by the phase detector;
- wherein the RF receiver comprises:
- a frequency generator unit configured to provide a first LO signal to an input of the RF receiver when in the calibration mode, and a second LO signal lower in frequency than the first LO signal;
- and
- a mixer configured to receive the input to the RF receiver on an input port, and to mix the input signal with the first and second LO signals when in the calibration mode, and to provide a mixed output signal as a result.
Dependencies are inferred from the claim text.