Distributed amplifier MMIC with 21 dB gain and 90 GHz bandwidth using InP-based DHBTs

This paper reports a state-of-the-art distributed amplifier intended for use in 100 Gbit/s optical communication systems (Ethernet). Using an InP DHBT technology, exhibiting cut-off frequency values of more than 275 GHz for both fT and fmax, the amplifier achieved a gain of 21 dB and a 90 GHz 3-dB bandwidth, resulting in a gain-bandwidth product (GBW) of 1 THz. To our best knowledge, this represents the highest gain bandwidth product achieved for single-stage amplifiers in any technology reported to date.