ADD-IN CARD EDGE-FINGER DESIGN/STACKUP TO OPTIMIZE CONNECTOR PERFORMANCE

摘要

A technique to simultaneously reduce high-frequency insertion loss and cross-talk for a multi-layered add-in card is disclosed. The technique is based on selective removal of ground and power planes beneath the edge fingers. This selective removal of power and ground planes removes excess capacitance at the edge fingers, lowering the insertion loss at high frequencies, while maintaining an impedance match with an associated connector. Simultaneously, the leftover metallic ground/power plane provides electromagnetic shielding and thus reduces the cross-talk between the differential pairs. Optimum performance of the connector with minimized insertion loss and cross-talk can be obtained for high-speed analog and digital applications.