Impedance Matching

Transmission Line Elements on Smith Chart Web App

I've successfully added transmission line elements to the Smith Chart matching web app here on These include series, shorted shunt section, and open shunt section. There's a trick you can use to have these transmission line elements use an arbitrary characteristic impedance. The elements adopt the same characteristic impedance as the chart normalization impedance (default is 50 Ohms).

Analytical Impedance Match with Python

I created a quick Python function to calculate the component values for an impedance match between two real (resistive) terminations using the technique taught in the Introduction to Impedance Matching course. Here is what the code ends up looking like, and it shows how useful Python can be for working as a "quick programmable calculator." In the old days, I might have been tempted to program my old HP48 calculator to crank out the same values. It only took a few minutes to put the code together, which is the beauty of working with Python.

Smith Chart Matching HTML 5 Version

An early version of the Smith Chart web app is now available to try out. There are a couple of issues that I will be working on initially, such as the frequency entry dialog box appears to be transparent for some reason. I'll also be working on the layout to try and make the various parts of the app fit better on the page. At the moment, the app is only optimized for mouse input and does not respond to touch-based dragging events (to move elements around on the chart).

Applets are Dead(?) Long Live JavaScript

Now that browsers are dropping support for the Java plug-in, it seems that the days of applets are coming to an end. Although Java applets never dominated the mainstream web experience as much as more popular Flash-based content, they did find a niche in scientific and engineering applications - which is one of the few areas where they will likely be missed.

Smith Chart Matching Web App


Rex Frobenius

Use this handy Smith Chart web app to create matching networks. Easiest tool to use: drag elements right on the chart! Supports multiple frequencies, transmission line elements, etc. Note: please register for a free account for continued access to the Smith Chart app.  

New HTML 5 Version Now Available A new version of the popular Smith Chart app that does not require any plug-in has now replaced the older Java applet version.


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