Patent ID: 7769361

Claim:
An apparatus including a frequency converter, said frequency converter comprising: a first passive mixer having first and second input terminals; a second passive mixer having first and second input terminals; and first, second, third, and fourth transistors, each of the four transistors having a gate and a channel region that is proximate to the gate and has two ends, wherein the channel regions of the first and third transistors are coupled in series between the first input terminal of the first passive mixer and the first input terminal of the second passive mixer, and wherein the channel regions of the second and fourth transistors are coupled in series between the second input terminal of the first passive mixer and the second input terminal of the second passive mixer, and wherein the first input terminal of the first passive mixer is arranged to receive one side of a differential radio-frequency current signal via the channel region of the first transistor, and the second input terminal of the first passive mixer is arranged to receive the other side of the differential radio-frequency current signal via the channel region of the second transistor, and wherein the first input terminal of the second passive mixer is arranged to receive one side of the differential radio-frequency current signal through the channel region of the third transistor, and the second input terminal of the second passive mixer is arranged to receive the other side of the differential radio-frequency current signal through the channel region of the fourth transistor.