High-speed data transmission in a rack system with coaxial board connectors

The speed at which data can be transmitted in communication rack systems is limited by crosstalk simultaneous switching noise in the data signal. We experimentally evaluated the relationship between this noise and transmission speed. The experimental rack system had 24 independently driven channels consisting of a driver-printed board assembly (PBA), connector, back panel (BP), connector, and receiver-PBA. The drivers are 210-270 ps edge rate ECL devices. The rack structure allowed the line length on the panel to be changed from 15 cm to 45 cm by changing the slots of the driver and receiver cards. A newly developed small, high-density multicoaxial package connector was used, and an error rate detector was used to determine the error-free transmission speed at various receiver reference voltages. For a 60-cm line, the maximum speed of the rack system was 622 Mb/s, more than four times that achieved when using a conventional multipin connector