The Designer's Guide Community
Welcome, Guest. Please Login or Register. Please follow the Forum guidelines.
Nov 30th, 2023, 11:23pm
Pages: 1
Send Topic Print
Plot s11 on Smith chart (Read 960 times)
Junior Member

Posts: 12

Plot s11 on Smith chart
Nov 19th, 2016, 5:32pm

When i say i am plotting s11 parameter on Smith chart, does it mean that s11 gets converted to z11 and hence plots normalised impedance value on SC.

Similarly what about s21 can it be plotted on SC since it is a gain parameter.

KINDLY clear my confusion.
Back to top
View Profile   IP Logged
Horror Vacui
Senior Member

Posts: 127
Dresden, Germany
Re: Plot s11 on Smith chart
Reply #1 - Jan 31st, 2017, 2:18am
S11 is like a reflection coefficient. There is a bijective connection between reflection coefficient and normalized impedance. No conversion is needed on the smith chart - that's point of the chart! - just different scales are used.

S21 is a ratio of incident and reflect waves. The waves are merely on different ports, so in princip it is the same as S11. Nevertheless I do not see the point of using a Smith chart for S21. The middle point of the Smith chart has no meaning here, no matching is required in this parameter. If you have S21=10+j0, then where would you add it on the Smith chart? A conventional magnitude plot says more about S21.
Back to top
View Profile   IP Logged
Pages: 1
Send Topic Print
Copyright 2002-2023 Designer’s Guide Consulting, Inc. Designer’s Guide® is a registered trademark of Designer’s Guide Consulting, Inc. All rights reserved. Send comments or questions to Consider submitting a paper or model.