Patent ID: 7991376
Filing Date: 2011-08-02
Classification: H03D

Abstract:
1. A mixer comprising: a mixing unit configured to mix high frequency data signals and local oscillation (LO) signals, generate first and second low frequency data signals, and output the first and second low frequency data signals to first and second output terminals, respectively; a common mode amplification unit coupled to the mixing unit, the common mode amplification unit configured to compare a common mode voltage of the first and second low frequency data signals and a predetermined reference voltage, the common mode amplification unit further configured to output a feedback signal at a control node based on the comparison; a first load transistor coupled to the first output terminal and the control node, the first load transistor configured to provide the first output terminal with a first load current corresponding to the feedback signal; a first calibration transistor unit connected in parallel to the first load transistor in order to calibrate an input impedance of the first output terminal; and a first current mirror unit coupled to the first calibration transistor unit, the first current mirror unit configured to discharge a first calibration current that is output from the first calibration transistor unit to prevent the first calibration current from entering the first output terminal.