Patent ID: 8090340

Claim:
A calibration method for a direct conversion receiver, wherein: the direct conversion receiver comprises a mixer having a differential loading pair; and the differential loading pair comprises a binary weighted resistor having adjustable resistance with a linear relationship to a digital code; the calibration method comprises: setting the digital code to a first value, such that a first mismatch of the differential loading pair induces the mixer to output a first DC offset; setting the digital code to a second value, such that a second mismatch of the differential loading pair induces the mixer to output a second DC offset; establishing a two dimensional linear relationship between the mismatches and the DC offsets based on the first and second mismatches and DC offsets; performing an interpolation on the two dimensional linear relationship to determine a third mismatch corresponding to a minimum DC offset; and generating a third digital code from the third mismatch to be the calibration result.