The model FO-MDA-20-25DD-1 dual-channel DQPSK modulator driver from Narda, an L-3 Communications company, is suitable for 40- and 100-Gb/s lightwave communications systems. It has been tested at data rates as high as 113 Gb/s. It is designed for use with a Sierra Monolithics SMI 4025 DQPSK multiplexer/clock multiplier unit on the input and an Avanex Mach-Zehnder lithium-niobate MZ DQPSK modulator at its output, although additional models are available for use with other modulators. The FO-MDA-20-25DD-1 has a maximum data rate of 35 Gb/s, 30 dB of gain per channel, and output of more than 8 Vpp. It is housed in a package measuring 36 x 28 x 8 mm with GPPO connectors.