High-speed signal transmission at the front of a bookshelf packaging system

A front-connection technique using the front-side of the circuit board in rack systems configured like bookshelves is proposed to increase pin-counts for high-throughput switching modules (>20 Gb/s). This configuration technique was implemented using newly developed front connectors and flexible printed-circuit (FPC) cables that are both impedance-matched. This configuration enables the use of a new transmission route that meanders through every signal transmission line of every circuit board, backplane, and FPC cable. This route can extend the functional block size from the size of the circuit board to that of the unit, In a signal transmission experiment between circuit boards with this meander route passing through signal lines of an 18-cm-long FPC cable and over a distance of ten slots in the backplane, error-free (<10/sup -11/) signal transmission of 2/sup 23/-1 nonreturn-to-zero (NRZ) pseudo-random bit sequences (PRBS) at 622.08 Mb/s was obtained.