EMI associated with inter-board connection for module-on-backplane and stacked-card configurations

EMI associated with inter-board connection was studied through common-mode current measurements and FDTD modeling for stacked-card and module-on-backplane configurations. Three types of connections were investigated experimentally including an open pin field connection, an "ideal" semi-rigid coaxial cable connection, and a production connector. Both microstrip and stripline signal routing on the PCB were investigated. The results indicated signal routing on the PCBs or the inter-board connection can dominate the EMI process. Several cases of connector geometries were studied using FDTD modeling and good agreement was achieved between the measured and FDTD results.