Equivalent circuit models from S-parameters

Mühlhaus Circuit Model Fit is an ADS add-on to create accurate, reliable circuit models from silicon RFIC inductor S-parameters. The workflow is fast, easy to use and fully automated. Symmetric and asymmetric inductors are supported, with or without center tap.


Your input:

  • S-parameter data file (*.s2p or *.s3p) for the inductor

Circuit Model Fit does all this automatically:

  • Analyze the input data, choose equivalent circuit model and good starting values
  • Automatically set up goals and optimization parameters, optimize in ADS
  • Create Spectre *.scs netlist file from optimized equivalent circuit model

User’s Guide (PDF, 1.5MB)
Video Tutorial (Youtube)

Quality and accuracy of the circuit model

How is Mühlhaus Circuit Model Fit different from other inductor modelling tools?

  • Advanced equivalent circuit models, which are accurate over a wider frequency range.
  • Creates ADS circuit model and Spectre *.scs netlist file
  • Fully integrated to the ADS framework (ADS license required).
  • Can be customized by the user as needed.

What is the advantage of this physics-based model over Broad Band SPICE models?

  • Stable and well behaved in transient and PSS simulations
  • Accurate for noise and phase noise
  • Equivalent circuit models are physically meaningful, and give a physical understanding of the device.

The picture below shows an example of the excellent agreement between input data and equivalent circuit model for a center tapped inductor in 130nm SiGe technology.

(click to view full size)

Easy to use

Circuit Model Fit for RFIC Inductors is very easy to use, and fully integrated into the ADS framework.


Circuit Model Fit for RFIC Inductors is implemented as an ADS designkit, and is compatible with ADS releases 2012.08 or newer. Models are compatible with a wide range of Silicon based technologies, e.g. RF-CMOS and SiGe BiCMOS technologies.

Please note that this silicon RFIC tool is not designed for GaAs/GaN technologied or PCB, which require a different circuit model topology.

Pricing and availability

Circuit Model Fit for RFIC Inductors is immediately available.
For your free download, please contact us!

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User’s Guide (PDF, 1.5MB)
Video Tutorial (Youtube)