DOWN CONVERSION CIRCUIT WITH INTERFERENCE DETECTION

摘要

A down conversion circuit (30) for a receiver circuit (10) is disclosed. It comprises a first mixer (70) arranged to down convert an RF signal with a first LO signal (LO1) thereby generating a first down converted signal. It further comprises a second mixer (80) arranged to down convert the RF signal with a second LO signal (LO2) having the same LO frequency as the first LO signal (LO1) but a different and a second duty cycle thereby generating a second down converted signal. The second mixer (80) has an enabled and a disabled mode. The down conversion circuit (30) also comprises a third mixer (140) arranged to down convert the RF signal with the second LO signal (LO2) thereby generating a third down converted signal. A passive output combiner network is used to combine the first and the second down converted signals such that harmonically down converted signal content present in the first down converted signal and harmonically down converted signal content present in the second down converted signal cancel in a combined output signal of the down conversion circuit. The down conversion circuit further comprises a detection unit (150) adapted to detect interference based on the first and third down converted signals and to selectively set the second passive switching mixer (80) in the enabled mode for counteracting the interference or in the disabled mode for saving power compared with the enabled mode based on the detection. A corresponding receiver circuit a corresponding communication device and a corresponding method are also disclosed.