Experimental evaluation of NRZ and duobinary up to 48 Gb/s for electrical backplanes

In order to overcome bandwidth limitations and to reduce intersymbol interference, advanced modulation and equalization are widely applied in high speed backplane applications. In this paper, we explore transmission beyond 40Gb/s across a commercial Megtron 6 11.5 inch electrical backplane, and demonstrate a record, error-free, serial electrical duobinary transmission up to 48Gb/s including backplane connectors. Compared to NRZ, the equalized duobinary transmission over the backplane indicates a great performance improvement due to its higher bandwidth efficiency, which has the potential to increase the speed limit of backplane channels. In order to verify the backplane transmission performance, the bit error rates are presented at different data rate and over different backplane channel lengths.