  Recent progress in silicon-based photonic integrated circuits (PICs) have
opened new avenues for analog circuit designers to explore hybrid integration
of photonics with CMOS ICs. Traditionally, optoelectronic systems are designed
using discrete optics and electronics. Silicon photonic (SiP) platforms provide
the opportunity to realize these systems in a compact chip-scale form factor
and alleviate long-standing challenges in optoelectronics. In this work, we
analyze multi-bias tuning in Ring-Assisted Mach Zehnder Modulator (RAMZM) and
resulting trade-offs in analog RF photonic links realized using RAMZMs.
Multi-bias tuning in the rings and the Mach-Zehnder arms allow informed
trade-offs between link noise figure and linearity. We derive performance
metrics including gain, noise figure, and linearity metrics associated with
tuning of multiple bias settings in RAMZM based links and present resulting
design optimization. Compared to MZM, an improvement of 18
dB/Hz$^{\frac{2}{3}}$ in SFDR is noted when RAMZM is linearized. We also
propose a biasing scheme for RAMZM that provides 6x improvement in slope
efficiency, or equivalently, 15.56dB in power Gain over MZMs (single drive)
while still providing similar SFDR performance ($\sim$ 109
dB/Hz$^{\frac{2}{3}}$) as MZMs. Moreover, a method to improve gain in
photodiode saturation limited links is presented and studied.
