V15 – What is de-embedding?

Important Modeling Concepts

De-embedding is the process of calibrating the ports, similar to a calibration of an RF measurement system with the probes or connectors used in the measurement. Sonnet de-embedding is performed automatically, behind the scenes, and in most cases, is not a concern for the user. However, just as in an RF measurement, understanding of the inner workings of the process can sometimes allow you to design your circuits in such a way as to produce more accurate results or analyze your circuit more efficiently.

Each port in a circuit analyzed by em introduces a discontinuity into the analysis results. In addition, any feed transmission lines that might be present introduce phase shift, and possibly, impedance mismatch and loss. Depending upon the nature of your analysis, this may or may not be desirable. De-embedding is the process by which the port discontinuity and transmission line effects are removed from the analysis results.

To summarize, this algorithm performs the following analysis steps when enabled:

  1. Calculates port discontinuities.

  2. Removes effects of port discontinuities from analysis results.

  3. Optionally shifts reference planes (negates effects of feed or port transmission lines from analysis results).

  4. For most port types, calculates transmission line parameters Eeff and Z0 for the feed transmission lines.

    Run em with de-embedding enabled whenever you do not want to include the effects of port discontinuities in your analysis results. The De-embed option is selected by default in the analysis controls.

images/button_manuals.gif The em de-embedding algorithm is described in detail in the ''De-embedding'' chapter of the Sonnet User's Guide.