Microwave Journal
3D Smith Chart tool

3D Smith Chart Tool Version 1.02 Released Adding New Features

July 17, 2019

3D Smith chart announces a new version (1.02) of the 3D Smith chart with new features. The original 3D Smith chart tool (version 1.01) extended the Smith chart capabilities for the first time since the 1939s to make it usable for circuits with negative resistance based on a unit sphere that plots circuits with reflection coefficient magnitudes larger than 1 by mapping them as arcs on the 3D sphere. The South-represents active areas with negative resistance, North areas represent passive with positive resistance, East inductive and West capacitive. (North pole: perfect match, South pole infinite mismatch).

Now, based on the article, "Reconfigurable RF Electronic Functions Designed with 3D Smith Charts in Metal-Insulator-Transition Materials," several new features have been added to the 3D Smith chart version 1.02 Windows 64-bit compatible tool. The new features include:

  • 3D frequency (live) sweeping representation (for visualizing the dynamics of the S parameters variation). For example, negative capacitances and positive inductances can be directly distinguished due to their opposed frequency sweeping orientation. Furthermore, no uncertainty on the sweeping range start and end points occurs now while interpreting the results.
  • Unique inductor quality factor visualization over the S11 parameters in 3D, 3D inductance display over the S11 parameter and Q as a generalized cylinder of a radius corresponding to its normalized value for each frequency point. Different models of definitions are used (shunt inductor model, series inductor model).
  • Several improvements in terms of rendering/visualizations, helpful both in actual design and learning the 2D Smith and 3D Smith chart concepts (axes system, “Greenwich” constant resistance meridian, surface transparency, etc.).

Above is an example of one of these new features showing a 3D frequency sweep representation over S11. The paths of the 2 nH inductor and -2 pF capacitor represented between 1 and 3 GHz.

The tool is well suited for amplifier stability analysis, oscillator design, filters and group delay analysis.