Patent ID: 7305217

Claim:
A mixer for mixing a radio frequency signal with a local oscillator signal to provide an intermediate frequency signal, comprising: a substrate having a top surface and a bottom surface; a local oscillator balun mounted on the top surface including, a first, second and third transmission line, the first and second transmission lines connected at a first node and the second and third transmission lines connected at a second node; a radio frequency balun mounted on the top surface including, a fourth and fifth transmission line and a circuit line, the fourth and fifth transmission lines connected at a third node and the fifth transmission line and the circuit line connected at a fourth node; and a diode package mounted to the top surface and connected to the nodes, the diode package having a first, second third and fourth diode, the first diode connected between the first and second nodes, the second diode connected between the third and fourth nodes, the third diode connected between the first and fourth nodes, the fourth diode connected between the second and third nodes.