Patent ID: 7302249

Claim:
An integrated circuit mixer having elements formed on a silicon substrate, and which elements comprise: a non-linear circuit device for mixing signals; a passive balun comprised of a) a first insulating layer on said silicon substrate, b) a ground plane on said first insulating layer, c) a second insulating layer on said ground plane, d) a first microstrip line on said second insulating layer and having a predetermined shape, e) a third insulating layer on said first microstrip line, f) a second microstrip line on said third insulating layer and being generally coextensive with said first microstrip line, said second microstrip line having a first section of a first width and a second section of reduced width; said passive balun having an input port for receiving an RF signal, and first and second output ports; a local oscillator balun having an input port for receiving a local oscillator signal, and first and second output ports; said first and second output ports of said passive balun being connected to said non-linear device; said first and second output ports of said local oscillator balun being connected to said non-linear device; an output port connected to said non-linear device for delivering an IF signal as a result of the mixing of said RF and said local oscillator signals.