US Patent 7566952 On-chip circuit pad structure

Shielded circuit pad is provided where the parasitic capacitance is tuned out by the inclusion of a shunt transmission line stub which reduces the substrate induced loss in millimeter-wave applications. The circuit pad is located on the substrate, with a shield located beneath the circuit pad, and the shunt transmission line stub attached to the circuit pad. Accordingly, controlled impedance is obtained for millimeter-wave applications. The spacing between the circuit pad and the shield may then be minimized.