The Smith chart was developed by Philip Smith at Bell Telephone's Radio Research Lab during the 1930s. 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 trademark on the Smith Chart recently expired, and Ms. Smith sold the Copyright for the Smith Chart to the IEEE MTT Society in April 2015. Dr. Richard Snyder participated in the negotiations with Ms. Smith and her family. You may notice from time to time that the Smith chart is used in the background on presentations at MTT-S venues. It also is used as wallpaper on the Microwaves101 web site (partnered with MTT-S since 2014), look to the right and left of this paragraph and admire it!