A 3-Vppd 730-mW Linear Driver IC Using InP HBTs for Advanced Optical Modulations

摘要

This paper presents a 3-Vppd 730-mW linear optical modulator driver IC for advanced modulations suitable for optical communications systems operating at 100-Gb/b/ch and beyond. The driver was designed and fabricated using 0.5-um-emitter InP HBT technology, which yields a peak ft of 290 GHz, a peak fmax of 320 GHz, and BVceo of approximately 4 V. The linear driver has a two-stage lumped configuration comprising a variable-gain amplifier (VGA) and an output cascode amplifier. It provides linear differential output amplitude of up to 3 Vppd and consumes only 730 mW. It has a large bandwidth of 37.8 GHz and a maximum differential gain of 16.2 dB with 6-dB variable gain range. Total harmonic distortion (THD) is as low as 1.2% at 1 GHz and better than 3.8% up to 16 GHz. The driver provides very clear binary and multilevel output and can be applied to optical transmissions of 100-Gb/s/ch and beyond.