An 89.5 GHz 3-dB Bandwidth 80 Gb/s NRZ Distributed Amplifier in a 0.7-μm InP Technology

A design of 89.5 GHz 3-dB bandwidth distributed amplifier in a 0.7-μm InP technology is presented in this work. A unit cell's input capacitor introduces a loading effect in a distributed amplifier. This loading effect includes the limitation of bandwidth and group delay flatness. This work provides a bandwidth and group delay analysis of this unit-cell input capacitor. Based on this analysis, an optimized broadband distributed amplifier design methodology is provided. With this design methodology, an 89.5 GHz 3-dB bandwidth distributed amplifier is presented in a 0.7-μm InP technology. At 89.5 GHz, its OP1dB is 8.8 dBm. Its DC power consumption is reduced to 510mW, and its FoM reaches 2.12. And it supports an 80 Gb/s NRZ data rate. This design methodology achieves a good balance among bandwidth, gain, and power consumption and provides an optimized broadband driver for an electrical-optical interface.