Signal Integrity Engineer

Job Title

Signal Integrity Engineer

Role Summary

Design and validate signal integrity for Lightmatter's photonics-enabled systems, focusing on high-speed interfaces and package-to-system interactions. Work within the Signal Integrity, Power Integrity and Packaging team to influence architecture, perform analysis, and support lab bring-up through product development.

Experience Level

Mid-level — requires a minimum of 5 years of related signal integrity experience.

Responsibilities

Deliver signal integrity analysis, simulation, measurement, and guidance across digital, analog, and photonics domains to meet product specifications.

• Plan and execute moderate to complex SI tasks for high-speed interfaces such as PCIe, UCIe and SerDes.
• Analyze channel characteristics (S-parameters, insertion loss, return loss, crosstalk) and recommend mitigations.
• Perform SI simulations and analyses (eye diagram, jitter, equalization) and adapt procedures for new designs.
• Collaborate with hardware designers and PCB layout engineers to influence stack-ups, routing, vias, and termination.
• Perform detailed lab measurements and characterization using oscilloscopes, VNAs, TDRs, and network analyzers to validate designs and debug issues.
• Participate in design reviews, present findings, and document SI guidelines and test results for stakeholders.

Requirements

Minimal qualifications and technical skills required; preferred skills listed separately.

Must-have:

• Minimum 5 years of professional experience in signal integrity for high-speed interfaces.
• Proficiency with SI simulation and analysis tools such as Ansys Siwave, HFSS, and Keysight ADS.
• Strong understanding of transmission line theory, impedance matching, and equalization techniques.
• Experience with signaling protocols including SerDes, UCIe, and PCIe.
• Practical PCB design/layout knowledge for high-speed signals (layer stack-up, routing, via design).
• Hands-on experience with lab equipment for signal measurement and characterization (oscilloscopes, VNA, TDR, network analyzers).
• Ability to write scripts to automate simulation flows (Python, JavaScript, Ocean scripts, or SKILL).
• Ability to document and communicate technical results to cross-functional teams.
• Capacity to comply with U.S. export control laws.

Nice-to-have:

• Understanding of CMOS process technologies and their impact on SI.
• Proven problem-solving and debugging skills for complex SI issues.
• Demonstrated ability to build relationships with stakeholders and work independently with appropriate judgment.

Education Requirements

B.S. or M.S. in Electrical Engineering or a relevant technical field (as stated in the posting).

About the Company

Company: Lightmatter

Headquarters: Boston, Massachusetts, USA

Lightmatter develops photonic AI data-center infrastructure and optical chips for extreme-scale AI and HPC. The company invented the Passage 3D‑stacked photonics engine to provide high-bandwidth, low-latency interconnects across large-scale processors and raised $400M in Series D financing at a reported $4.4B valuation.