Patent ID: 8198933

Claim:
A double balanced mixer circuit comprising: a differential pair of first amplifier elements having first differential control terminals and respective first amplifier paths responsive to a first RF differential input signal applied to said first differential control terminals; double differential pairs of second amplifier elements comprising double second differential control terminals and double second amplifier paths responsive to a second RF differential input signal applied to said double second differential control terminals; and differential output terminals connected with said double second amplifier paths; and coupling elements providing first and second parallel DC connections between DC voltage supply rails for said first amplifier paths and said double second amplifier paths respectively and a series RF connection of said first amplifier paths and second double amplifier paths between said supply rails so as to produce a mixed differential amplified signal at said differential output terminals wherein said coupling elements include respective transmission lines in said first amplifier paths connected between one of said DC voltage supply rails and respective ones of said first amplifier elements and a common transmission line connected between the other of said DC voltage supply rails and both said first amplifier elements; wherein said coupling elements include at least one transmission line connected between said second amplifier elements and said other DC voltage supply rail; and wherein said coupling elements include transmission lines connected between respective pairs of said second amplifier elements and a node, and another transmission line connected between said node and said other DC voltage supply rail.