Volume: 72, Issue: 7, July 2024
Shengpu NiuA Linear Modulator Driver With Over 70-GHz Bandwidth 21.8-dB Gain and 3.4-Vppd Output Swing for Beyond 120-GBd Optical Links
Abstract
DOI: 10.1109/TMTT.2023.3342624
IEEEXplore: https://ieeexplore.ieee.org/document/10372185
Device
Linear differential modulator driver for optical links in 55nmSiGe BiCMOS with fT / fMAX of 330/370 GHz and BVCEO/BVCBO of 1.5/5.4 V
Spectrum
10 MHz to 70 GHz (and beyond, depending on peaking and gain control)
Novelty
A Gilbert cell VGA with variable degeneration resistors controls the signal power level delivered to the main stage and improves the linear input swing range.
Multiple gain cells in the traveling wave output stage increase total gain and output voltage swing without sacrificing bandwidth performance.
Application
Optical links beyond 120 GBd
Performance
>70 GHz 3dB bandwidth; 256 Gb/s;
4.0 Vppd at 72 GBd, 3.425 Vppd at 128 GBd (PAM-4);
21.8 dB maximum low frequency gain, 10 dB gain control;
725 mW power consumption, 2.83 pJ/bit power efficiency.