#314 Simulation Issues with s2p File-based Inductors Issue created by rupokdas147 I encountered a problem while designing an amplifier using the IHP Open Source PDK with the following tools: Qucs-S 24.3: For schematic design Ngspice 43 and Xyce: For simulation Design Process: Initially, I completed the amplifier design using ideal components from Qucs-S. I replaced the ideal resistors and capacitors with the PDK-provided resistors and capacitors. The S-parameter values remained consistent, confirming proper functionality. To replace the ideal inductors (50 pH each): Designed the inductor layout. Simulated it in OpenEMS to generate the s2p file. Replaced the ideal inductors (L1, L2, L3) with the corresponding s2p files in the schematic. Problem: Replacing L3 with its s2p file works fine, and the simulation completes successfully. However, replacing L1 or L2 (or both) with their respective s2p files causes: Ngspice 43: The simulation does not start. Xyce: The simulation produces NaN (Not a Number) values in the results. Steps to Reproduce: Design an amplifier schematic in Qucs-S with three 50 pH inductors: L1, L2, L3. Replace ideal resistors and capacitors with PDK components. Replace inductors as follows: Replace L3 with its s2p file: simulation works fine. Replace L1 and/or L2 with their s2p files: simulations fail as described. Run simulations in Ngspice 43 and Xyce to observe the issue. Additional Details: All s2p files were generated using OpenEMS simulations and validated to ensure physical feasibility. The issue occurs consistently when L1 or L2 (or both) are replaced with s2p files, regardless of whether L3 remains an ideal inductor or is also replaced with its s2p file. Expected Behavior: The simulations should complete successfully for all combinations of s2p-based inductors, just as they do for ideal inductors and for s2p-based L3. Request: Please investigate why Ngspice fails to start and Xyce produces NaN values when specific s2p-based inductors (L1, L2) are used. I attached the s2p file, schematic and Netlist. Thank you! Amplifier.zip Ngspice 43: image Xyce: image IHP-GmbH/IHP-Open-PDK