| CPC H03D 7/1458 (2013.01) [H03D 7/1441 (2013.01)] | 19 Claims |

|
1. A frequency mixer, comprising:
a transconductance circuit connected to an input signal terminal, and configured to generate a differential signal according to an input signal from the input signal terminal and output the differential signal through a first output terminal and a second output terminal of the transconductance circuit;
a switch circuit connected to a local oscillator signal terminal and the first output terminal and the second output terminal of the transconductance circuit, and configured to perform frequency mixing on a local oscillator signal from the local oscillator signal terminal and the differential signal to generate a mixed signal and output the mixed signal through a first output terminal and a second output terminal of the switch circuit;
a load circuit connected to an output signal terminal and configured to provide a load; and
an amplification circuit connected between the switch circuit and the load circuit and configured to amplify the mixed signal,
wherein the amplification circuit comprises:
a common-gate path comprising a first transistor device and a second transistor device having gate electrodes thereof coupled to each other; wherein the first transistor device has a source electrode connected to the first output terminal of the switch circuit, and a drain electrode connected to the first output terminal of the amplification circuit; and the second transistor device has a source electrode connected to the second output terminal of the switch circuit, and a drain electrode connected to the second output terminal of the amplification circuit; and
a common-source path comprising a third transistor device and a fourth transistor device having source electrodes thereof coupled to each other; wherein the third transistor device has a gate electrode coupled to the first output terminal of the switch circuit, and a drain electrode coupled to the second output terminal of the amplification circuit; and the fourth transistor device has a gate electrode coupled to the second output terminal of the switch circuit, and a drain electrode coupled to the first output terminal of the amplification circuit.
|