| 摘要 |
A technique for cancelling out target IM2 components in a wireless receiver's mixer output is disclosed. A differential RF signal and a differential local oscillator (LO) signal are mixed by a mixer to demodulate the RF signal. A first common node signal is generated between a first resistor and a second resistor coupled across the mixer's differential output terminals. A second common node signal is generated between a third resistor and a fourth resistor coupled across the differential output terminals, where a capacitor is coupled between the second common node and a power supply terminal. The second common node signal provides a stable reference signal for IM2 components above a certain frequency. The two common node signals are subtracted to create a difference signal. The difference signal is scaled by a scaling factor obtained during calibration. The scaled difference signal is coupled to the mixer output to offset IM2 distortion.
|
