High-performance inter-PCB connectors: analysis of EMI characteristics

Electromagnetic interference (EMI) coupling associated with inter-board connection is investigated herein. Two experimental techniques, based on |S.sub.21| measurements, including both common-mode current and near-field measurements, are reported. Both methods, as well as finite difference time domain (FDTD) modeling, were used as experimental and numerical tools for inter-printed-circuit-board (inter-PCB) connector evaluation. The EMI performance of a lab-constructed stacked-card connector, and a commercially available module-on-backplane connector were studied. EMI characteristics of the connectors are demonstrated by investigating a few aspects of the design: type of shield/ground blade for signal return, number and length of ground pins, signal pin designation, etc. Good agreement is achieved between the measurements and the FDTD modeled results. Index Terms--Common-mode current, finite-difference time domain (FDTD), inter-printed-circuit-board (inter-PCB) connector, near field, S parameter.