NEC-LIST:NEC--LIST: Smith Chart.

Good day All,

I am a little surprised at all the traffic on Smith Chart programs.
Personally, I consider the Smith Chart to be a limiting and obsolete graphical
tool, like the slide rule. All the equations being used in the programs would
better serve the user if the display were power gain or impedance vs.
frequency on a rectangular plot.

Exact design equations are available for commonly-used simple networks such as
the L-section, T, Pi, short-line equivalents, and the single-stub network.
These are all easily programmed. Speaking of the single-stub system, the
usual Smith Chart method, and the textbook equations, assume that the lines
involved will have the same wave impedance as the system impedance. This
isn't necessary, and more compact designs can be found by choosing different
wave impedances for the stub and the cascade line. I derived the equations
for this case decades ago, when I was first teaching electromagnetics. More
complex and broadband matching problems have to be solved by numerical
methods. Can you see the passband ripple on a Smith Chart?

Doug Miron

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