Convenience for graphical design of a matching network. There¡¯s also sort of a qualitative thing that you recognize particular ¡°shapes¡± on the chart as having particular significance.
And, if you¡¯re tuning a filter by turning a screw, sometimes seeing the Smith chart in real time is more ¡°intuitive¡± in some sense. I tune filters looking at magnitude S11 and S22 and S21. For a three section filter, you can see the three resonances, and looking from one end or the other tends to emphasize the section closest to the port you¡¯re looking at.
These days, with computers, seeing the Smith chart isn¡¯t as useful.
I use plots of magnitude and phase for design. And I work with a lot of more than one port systems, for which the Smith chart is less useful. For instance, if you¡¯re looking at the coupling among antennas in a phased array.
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On Apr 26, 2025, at 16:46, Brian Beezley <k6sti@...> wrote:
?On Sat, Apr 26, 2025 at 04:32 PM, W0LEV wrote:
The VECTOR reflection coefficient gives you far
more information than just frequency response!!
If you can plot the real and imaginary parts of an S-parameter as well as magnitude, phase, and SWR, what additional information does a Smith chart provide? Is the advantage that you get SWR and impedance in one curve as Stan suggests?
Brian
