Coherent Systems Architect - Mixed Signal AFE development

We are seeking a hands-on Coherent RF Architect to lead silicon bring-up, validation, and production test development for a mixed-signal Analog Front-End (AFE) featuring high-speed DACs, ADCs, PLL/clocking , and the RF electrical interface to the Transmitter and Receiver Optical Sub‑Assembly (TROSA) used in the optical coherent pluggable. The role owns end-to-end AFE characterization, from bench measurement and automation through correlation to simulation test coverage. 

NION2026

 

• Key Responsibilities 

• Silicon Bring-up & Debug

• Own first-silicon bring-up for DAC/ADC/PLL blocks: power-up sequencing, register access, clock tree bring-up, and initial functional validation.

• Debug mixed-signal issues across domains (clocking, analog biasing, digital control, interfaces, and test modes).

• Create debug playbooks and “known-good” procedures to accelerate lab triage and cross-team communication.

• Full AFE Characterization (Bench + Automation)

• DAC: SFDR, IMD, THD, SNR, ENOB, spurs vs. output amplitude, output frequency, sampling frequency, temperature, supply, and code format; static linearity where applicable.

• ADC: SNR, ENOB, SFDR, interleaving mismatch (offset/gain/timing), harmonic/spurious behavior, clock sensitivity.

• PLL/Clocking: phase noise, integrated jitter, spur analysis, jitter transfer/tolerance where relevant to the system.

• AFE-level metrics: frequency response, passband ripple, impedance/termination impact, crosstalk, noise coupling, and sensitivity to board/connector effects.

• Design experiments for PVT sweeps and margin analysis; develop guard-banding strategies aligned to production realities.

• RF characterization of TROSA

• Characterize RF electrical behavior of the Transmitter and Receiver Optical Sub‑Assembly, including bandwidth, frequency response, impedance matching, insertion and return loss, Gain, noise figure (where applicable), and linearity.

• Work closely with photonics, SiGe IC, and module teams to correlate electrical AFE performance to optical metrics.

• Support electro‑optical (E/O) and opto‑electrical (O/E) RF validation for coherent transmit and receive chains.

• Measurement Infrastructure & Data Analytics

• Build and maintain automated measurement systems using Python and standard instrument control (SCPI/PyVISA).

• Use robust data practices: versioned test scripts, metadata capture, calibration traceability, and reproducible analysis notebooks.

• Create dashboards/reports summarizing performance trends, correlations, and anomalies.

• Cross-Functional Collaboration & Requirements

• Work with design teams to define: test hooks, observability, calibration registers, and design-for-test requirements for analog blocks.

• Define measurable acceptance criteria aligned to coherent system requirements.

• Collaborate closely with Analog/RF design, SiGe IC teams, DSP, Signal Integrity (SI), photonics, module, and manufacturing teams.

Required Qualifications 

• Ph.D. in Electrical Engineering or Applied Physics with experience in mixed-signal silicon test/validation/characterization, high-speed electronics or systems.

• Strong fundamentals in high speed electronics and practical experience with test equipment such as high bandwidth oscilloscopes, phase noise analyzer, spectrum analyzer, VNA.

• Experience characterizing high-speed RF and mm-wave interconnects, amplifiers, and components

• Solid automation skills in Python including data pipelines and plotting.

• Ability to read schematics, understand board-level effects, and debug signal integrity/power integrity interactions.

• Comfortable in a fast-moving lab environment: hands-on probing, rework coordination, fixture bring-up

Preferred Qualifications 

• Experience with optical coherent systems and coherent transceiver architectures.

• Experience with MZ modulator drivers (MZMD) and TIAs in coherent links.

• Experience with high‑speed data converters, interleaved ADCs, and calibration techniques.