Calibration method for suppressing second order distortion
AssigneeMediatek Incorporation
InventorsChing-Shiun Chiu, Shou-Tsung Wang
Life of this patent
Estimating the term…
Abstract
Calibration methods and circuits for suppressing second order distortion in a direct conversion receiver. In the calibration method, a signal output by a down converter is filtered to obtain an interference signal, and strength of the interference signal is detected. A calibration code is obtained according to the detected strength of the interference signal, and the down converter is adapted according to the calibration code to suppress second order distortion.
Claims22
A calibration method for suppressing second order distortion in a direct conversion receiver, comprising:
- filtering a signal output by a down converter to obtain an interference signal;
- detecting strength of the interference signal;
- obtaining a calibration code according to the detected strength of the interference signal;
- and
- adapting the down converter according to the calibration code.
A calibration circuit for suppressing second order distortion in a direct conversion receiver, comprising:
- a down converter, down-converting a received signal and outputting a down-converted signal;
- a filtering unit coupled to an output of the down converter, outputting an interference signal;
- a detection unit coupled to the filtering unit, detecting strength of the interference signal;
- and
- a calibration code generator, coupled to the detection unit, generating a calibration code according to the detected strength;
- wherein the calibration code is fed back to the down converter such that the down converter is adapted according to the calibration code.
A direct conversion receiver, comprising:
- a signal receiver, receiving a incoming signal;
- a down converter, down-converting the received signal to a down-converted signal;
- a bandpass filter coupled to an output of the down converter, outputting an interference signal;
- a detection unit coupled to the bandpass filter, detecting strength of the interference signal;
- and
- a calibration code generator coupled to the detection unit, generating a calibration code according to the detected strength;
- wherein the calibration code is fed back to the down converter such that the down converter is adapted according to the calibration codes.
Dependencies are inferred from the claim text.