One thing you give up when plotting reflection coefficients on a Smith chart is a direct reading of a frequency axis. Yes, it is possible to go outside the Smith chart 'unity' circle, but only with an active device because this implies negative resistance. All imaginary impedances from - infinity to + infinity are represented, but only positive real impedances appear on the 'classic' Smith chart. The Smith chart contains almost all possible impedances, real or imaginary, within one circle. What matters is knowing the basics and how to use them, like always. You can find books and articles describing how a Smith chart is a graphical representation of the transmission line equations and the mathematical reasons for the circles and arcs, but these things don't really matter when you need to get the job done. That's it! Transmission coefficient, which equals unity plus reflection coefficient, may also be plotted (see below). What is a Smith chart? It's really just a plot of complex reflection overlaid with an impedance and/or admittance grid referenced to a 1-ohm characteristic impedance. Some Smith chart links What's a Smith chart? Which way is up and where's that short circuit? If you want to download a Smith chart in pdf or gif format, we have several different ones in our download area!Ī clickable index to our Smith chart page:

If anyone else wants to be a technical contributor on their favorite microwave subject, please contact us. We've got our own Smith chart tutorial here, thanks to a fan from Florida, Mike Weinstein, who really knows this subject, and is a fine writer too. New for December 2018! The first year ECE students under the guidance of Dr S Raghavan, Professor, ECE dept., N I T Trichy, came out for the first time with the novel idea of putting a Smith chart on.

They're promoting European Microwave Week 2020 in Utrecht (the Netherlands) with this Smith Chart template. Update August 2019: Here's a cool template that we got from Frank at TNO, a research organization based in the Netherlands that is known for GaN, SiGe and AESA work. You may notice from time to time that the Smith chart is used in the background on presentations at MTT-S venues. Richard Snyder participated in the negotiations with Ms. Smith sold the Copyright for the Smith Chart to the IEEE MTT Society in April 2015. The trademark on the Smith Chart recently expired, and Ms. Be sure to check out our entry on Philip Smith in our Microwave Hall of Fame! Phil's widow until recently operated Analog Instruments, the company that sold the official Smith chart for many, many years. The Smith chart was developed by Philip Smith at Bell Telephone's Radio Research Lab during the 1930s. Click here to go to our main page on S-parametersĬlick here to go to a page on plotting Smith Charts with ExcelĬlick here page to learn about a three-dimensional Smith Chart

Smith chart impedance matching pdf