About Mixx Technologies Mixx Technologies is building next-generation optical interconnect solutions that enable true system-level integration for hyperscale data centers. We combine expertise in silicon photonics, packaging, fiber connectivity and system integration to deliver products that set new standards for performance, density, and scalability to drive the next generation of artificial intelligence. Position Overview We are seeking an SI/PI Engineer with deep hands-on expertise in full-wave electromagnetic modeling and circuit-level channel simulation for advanced semiconductor packages. In this role, you will build the package, connector, and socket models behind our 224G PAM4 optical interconnect modules, using tools such as Ansys HFSS and Keysight ADS, and turn them into clear design guidance for layout and architecture teams. You will own physical-layer signal and power integrity of the package; standards-level compliance analysis such as EECQ/COM.

Key Responsibilities
• Build 3D full-wave models of package interconnect, vias, breakouts, bump and ball transitions, and connector/socket interfaces in Ansys HFSS (or equivalent), with sound meshing, port setup, and convergence practice.
• Extract S-parameter and RLC models of package channels and PDNs using HFSS, SIwave, or Cadence Clarity/PowerSI, and deliver validated, passive, causal models to downstream teams.
• Simulate channels in Keysight ADS: cascaded S-parameter analysis, TDR/TDT, frequency
- and time-domain response, and transient or statistical eye analysis.
• Evaluate insertion loss, return loss, NEXT/FEXT, mode conversion, and impedance profiles against package, connector, and channel budgets up to and beyond 224G-class Nyquist frequencies.
• Set pre-layout routing rules, stack-up recommendations, and via/launch designs, and iterate with package layout designers to close margin.
• Perform sensitivity and tolerance studies on dielectric properties (Dk/Df), copper roughness, and manufacturing variation.




• Perform package-level PI analysis: PDN impedance versus target, decoupling optimization, IR drop, and current density, in partnership with the power architecture team.
• Develop de-embedding approaches and correlate simulation with VNA and TDR measurements from the validation lab.
• Deliver S-parameter models and channel data to the System Modeling team for EECQ/COM and standards compliance analysis.
• Document modeling methodology, results, and recommendations in clear technical reports and design reviews. Key Qualifications
• Bachelor's in Electrical Engineering or related field; Master's or Ph.
D. with a focus on electromagnetics, or high-speed design is preferred.
• 5+ years of hands-on SI/PI experience on semiconductor packages, substrates, or high-speed interconnects.
• Expert-level proficiency in Ansys HFSS, including parametric and optimization studies and complex 3D structures.
• Strong proficiency in Keysight ADS for channel simulation and S-parameter post-processing.
• Working experience with Ansys SIwave or Cadence Sigrity/Clarity for package-level extraction and PI analysis.
• Solid grounding in transmission-line theory, S-parameters, mixed-mode analysis, passivity and causality, and de-embedding techniques.
• Experience with channels at 112 Gbaud or higher
• Familiarity with VNA/TDR measurement and calibration, and with correlating measurement to simulation.
• Awareness of IEEE 802.3dj and OIF CEI-112G/224G channel requirements; COM experience is a plus
• Scripting skills in Python or MATLAB for automation and data analysis.
• Strong communication skills and the ability to collaborate across layout, power, mechanical, and system teams in a multi-site environment. Why Join Us At Mixx Technologies, you'll be part of a fast-moving team rethinking what's possible in AI infrastructure.

We offer
a team-oriented culture, deep technical challenges, and the opportunity to shape the mechanics behind the world's most advanced computing systems.

📌 Package SIPI Engineer (India)
🏢 Mixx Technologies
📍 India