Patent ID: 8064870

Claim:
A miniaturized dual-balanced mixer circuit of the type having a first input port for receiving a first input signal, a second input port for receiving a second input signal, and an output port for outputting an intermediate-frequency signal which is a mixed version of the first input signal and the second input signal; the miniaturized dual-balanced mixer circuit comprising: a first balun circuit unit, which has a single-port input interface and a four-port output interface, wherein the single-port input interface is connected to the first input port for receiving the first input signal, while the four-port output interface is used for outputting four balance-to-unbalance transformed signals; a second balun circuit unit, which has a single-port input interface and a four-port output interface, wherein the single-port input interface is connected to the second input port for receiving the second input signal, while the four-port output interface is used for outputting four balance-to-unbalance transformed signals; and a frequency-mixing circuit unit, which is capable of generating the intermediate-frequency signal by mixing the output balance-to-unbalance transformed signals from the first balun circuit unit and the second balun circuit unit; wherein in integrated circuit layout, the first balun circuit unit and the second balun circuit unit are each constructed on a plurality of distributed transmission lines whose layout patterns are based on a trifilar topology.