Click here to go to our second QuickSmith example
New for September 2026. QuickSmith is an on-line tool that was developed by Nathan, who dropped us this note:
(Here's) a tool for your links page: QuickSmith is a Smith chart and matching program that runs in a browser with nothing to install, free and MIT licensed. Drag components onto a ladder and the trace moves on the chart, with VSWR, return loss, insertion loss, loaded Q and bandwidth live beside it. It auto-matches to 50 ohms, imports Touchstone files from a VNA, sweeps frequency or a component, synthesizes microstrip and coax dimensions, and does amplifier design with stability, gain and noise circles.
QuickSmith was written in 1993 for Windows 3.1. As far as I’ve been able to establish, it was the first Windows Smith chart program with a graphical interface. It was ported to the web in 2017. The 2026 work was a major rebuild of the solver, chart, and test suite, along with Touchstone import, auto-matching, response graphs, microstrip/coax synthesis, named designs, and undo.
We added a link to QuickSmith on our cool links page, or you can take a shortcut and access it here:
https://quicksmith.online/
You can expect a short learning curve when you check out QuickSmith, but it's worth it. It makes it easy to visualize the direction that different elements have on an impedance. Let's start with an example to help you along...
QuickSmith Example 1. Match to 5-5j ohms
We picked that impedance out of a hat, it is representative of nothing in particular. Start the project by opening a browser window to the QuickSmith address. The default value of the load impedance is 50 ohms. Look for the editable window under the load (which is labeled RX) and type in 5 and -5, Then the load on the Smith Chart moves to the left side (low impedance) and slightly below the real axis, like this:
Now it's time to add a matching element. You can play around with different elements, but we will speed this up with advanced knowledge of what works. We selected a capacitor and dragged it to the first series position in the ladder. We left it at the default value of 1 pF. While we were at it, we changed the frequency from 100 MHz to 10,000 MHz, because this is a microwave website, not a UHF website. The match moves along a constant R contour as seen below. Note that for this entire example, we are looking at a single frequency point; in real life you will need to match a circuit over some appreciable bandwidth. Here we are playing checkers, real life is a chess match.
Now let's add a shunt inductor to the network and see what it does to the impedance match. At its default value of 1nH, it is moving along a constant real conductance contour and heading in the right direction. By the way, you can turn on conductance contours on the chart!
Now we go back and adjust the component values using the "-" and "+" buttons, until we hit a fifty ohm match. If you think this is fun like we do, you picked the right career!
You might have noticed a button labeled "Auto-match to 50 ohms". Let's see what that does... You need reset the problem by dragging and dropping the interconnect line icon the remove our good work, then push the Auto-match button. It provides two solutions, one is a series cap/shunt inductor (like we just did) and the other is a series inductor/shunt cap. Other solutions are of course possible. You can use a series inductor to get to the real axis, then use a quarter-wave transformer to hit 50 ohms.
Here is the other matching network result, starting with an 0.318 nH series inductor followed by a 0.955 pF shunt capacitor. It gets you to 50 ohms but the path is in the opposite direction.
This tool should used by students and practicing engineers to build an understanding of how different elements move you around the chart.
Example 2: broadband match
Click here to go to our second QuickSmith example