A two-channel parallel processing precoder IC module for 40Gbit/s optical d
uobinary transmission systems is described. The IC is fabricated with 0.1 m
u m InAlAs/InGaAs/InP HEMTs in order to achieve 20Gbit/s processing speed p
er channel with low power consumption. Error-free operation of the IC packa
ged as a module is confirmed at 21.5Gbit/s.