Down-conversion circuit with interference detection

摘要

A down-conversion circuit for a receiver circuit is disclosed. It comprises a first mixer 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 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 has an enabled and a disabled mode. The down-conversion circuit also comprises a third mixer 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 adapted to detect interference based on the first and third down-converted signals and to selectively set the second passive switching mixer 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.

主权项

1. A down-conversion circuit for a receiver circuit, comprising;
a first passive switching mixer arranged to down-convert a received radio frequency (RF) signal with a first local oscillator (LO) signal having a first duty cycle for generating a first down-converted signal at an output port of the first passive switching mixer; a second passive switching mixer arranged to down-convert the received RF signal with a second LO signal having a same LO frequency as the first LO signal and a second duty cycle, different from the first duty cycle, for generating a second down-converted signal at an output port of the second passive switching mixer, wherein the second passive switching mixer has an enabled and a disabled mode; a third passive switching mixer arranged to down-convert the received RF signal with the second LO signal for generating a third down-converted signal at an output port of the third passive switching mixer; a passive output combiner network operatively connected to the output ports of the first passive switching mixer and the second passive switching mixer and arranged 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; and a detection unit adapted to detect interference based on the first and third down-converted signals and to selectively set the second passive switching mixer 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.