Patent ID: 6882194

Claim:
A differential mixer including at least two input/output stages, at least a first of the two input/output stages including two identical branches, wherein each branch includes at least two bipolar transistors, bases of the two bipolar transistors of a first of the two identical branches connected together to define a first input/output terminal of a first pair of input/output terminals of the stage and bases of the two bipolar transistors of a second of the two identical branches connected together to define a second input/output terminal of the first pair of input/output terminals, the first and second input/output terminals being connected to a first D.C. current source individually by a respective isolating resistor; collectors of the two bipolar transistors of the first branch connected together to define a third input/output terminal of a second pair of input/output terminals of the at least one stage which forms a pair of input/output terminals of a second of the at least two stages of the mixer, collectors of the two bipolar transistors of the second branch connected together to define a fourth input/output terminal of the second pair of input/output terminals; wherein each of the emitters of the bipolar transistors of the first and second branch is individually connected to a low voltage reference line by a respective degenerative impedance; and wherein each of the first and second input/output terminals is connected to receive a respective RF input signal.