Linearity Analysis of BiCMOS Coherent TIAs

The linearity of a coherent TIA for optical transceivers is studied. The goal of the transimpedance gain is $ 74\mathrm{d}\mathrm{B}\Omega$. The study of the design parameters that limit each block’s linearity provides design directions for a TIA with THD equal to or lower than 1%. The analytical study uses the Ebers-Moll model and achieves design criteria confirmed by transistor-level simulations, carried out using a $130\mathrm{n}\mathrm{m}$ BiCMOS process.