Patent ID: 7298793

Claim:
A method for in-phase and quadrature mismatch calibration of a transmitter, comprising the following steps: generating a discrete-time signal x[n]=x(n·T s ), wherein x(t)=e j2πf T t and f T and T s are real numbers; obtaining a corrected signal x c [n] based on the signal x[n] and a set of correction parameters A p and B p , wherein x c [n]=A p ·x[n]+B p ·x*[n]; converting the corrected signal x c [n] to an analog corrected signal x c (t); applying in-phase and quadrature modulation to the analog corrected signal x c (t) and outputting a modulated signal x m (t); obtaining a first desired component measure W (1) (f T ) and a first image component measure W (1) (−f T ) from the modulated signal x m (t) with a first set of the correction parameters A p and B p ; obtaining a second desired component measure W (2) (f T ) and a second image component measure W (2) (−f T ) from the modulated signal x m (t) with a second set of the correction parameters A p and B p ; obtaining a third desired component measure W (3) (f T ) and a third image component measure W (3) (−f T ) from the modulated signal x m (t) with a third set of the correction parameters A p and B p ; obtaining a fourth and fifth set of correction parameters A p and B p based on the first, the second, and the third desired component measures as well as the first, the second, and the third image component measures; obtaining a fourth desired component measure W (4) (f T ) and a fourth image component measure W (4) (−f T ) from the modulated signal x m (t) with the fourth set of correction parameters A p and B p ; obtaining a fifth desired component measure W (5) (f T ) and a fifth image component measure W (5) (−f T ) from the modulated signal x m (t) with the fifth set of correction parameters A p and B p ; and obtaining a final set of the correction parameters A p and B p from the fourth and fifth sets of correction parameters.