Broadband Linear Drivers for 800G/1.6T Energy Efficient Optical Links

This work presents the design of a uniform distributed amplifier (LDHP) and a tapered distributed amplifier (LDHE) for linear-drive pluggable optical (LPO) transmitters. The drivers are implemented in the GlobalFoundries $\mathbf{9 H P +}$ 90-nm SiGe BiCMOS process. LDHP has $\mathbf{3. 1 \%}$ total harmonic distortion for 4 Vppd swing up to 22 GHz and achieves 100 GBd PAM-8 with an efficiency of $3.32 \mathrm{pJ} / \mathrm{bit}$. LDHE utilizes tapered output transmission line to obtain good efficiency and linearity and achieves 120 GBd PAM-4 at $2.52 \mathrm{pJ} / \mathrm{bit}$. The drivers are targeted for 800 Gbps and 1.6 Tbps optical links.