Patent ID: 6871059

Claim:
A field effect transistor mixer comprising: a) a balun that includes a transformer having a primary winding and a secondary winding, the primary winding coupled to a radio frequency signal input; b) a pair of field effect transistors, each transistor having a gate, a source, a drain, and a channel between the source and the drain, wherein i) the gates of the transistors are coupled to one another and to a local oscillator input, ii) one of the source and the drain of a first of the two transistors is coupled at a node to one of the source and the drain of the other of the two transistors, and the node is coupled to ground, iii) the other of the source and the drain of the first of the two transistors is coupled to one side of the secondary winding of the balun and the other of the source and the drain of the second of the two transistors is coupled to the other side of the secondary winding of the balun; and c) an intermediate frequency signal output coupled to a point in the circuit path between the first and second transistors, wherein, at the node, one of the source and the drain of the second of the two transistors is connected to ground, and the node is coupled to one of the source and drain of the first of the two transistors by a filter.