Transmitter capable of reducing local oscillation leakage and in-phase/quadrature-phase (I/Q) mismatch and adjusting methods thereof

摘要

An adjusting method for reducing local oscillation leakage or I/Q mismatch in a transmitter includes the steps of: (a) detecting a current extent of local oscillation leakage or I/Q mismatch; (b) determining if an adjusting direction is correct with reference to the current extent of local oscillation leakage or I/Q mismatch thus detected, maintaining the adjusting direction if correct, and reversing the adjusting direction upon determining that the adjusting direction is incorrect; and (c) adjusting a control signal according to the adjusting direction.

主权项

1. A transmitter comprising;
a first mixer for mixing a base band signal and a local oscillator signal so as to generate a radio frequency signal; a detecting unit for generating from the radio frequency signal a detection signal that represents an extent of local oscillation leakage or in-phase/quadrature-phase (I/Q) mismatch; and an adjusting unit coupled electrically to said first mixer for outputting a control signal thereto to control a current operating state of said first mixer, said adjusting unit being further coupled electrically to said detecting unit, and determining whether there is a reduction in the extent of local oscillation leakage or I/Q mismatch based on the detection signal from said detecting unit; wherein said adjusting unit maintains an adjusting direction for the control signal upon determining that the extent of local oscillation leakage or I/Q mismatch is reduced, reverses the adjusting direction upon determining that the extent of local oscillation leakage or I/Q mismatch is not reduced, and adjusts the control signal according to the adjusting direction.