R&S ZNB Series User Manual page 122

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R&S ZNB/ZNBT
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The circles for the points of equal resistance are centered on the real axis and
intersect at Z = infinity. The arcs for the points of equal reactance also belong to
circles intersecting at Z = infinity (open circuit point (1, 0)), centered on a straight
vertical line.
Examples for special points in the Smith chart:
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The magnitude of the reflection coefficient of an open circuit (Z = infinity, I = 0) is
one, its phase is zero.
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The magnitude of the reflection coefficient of a short circuit (Z = 0, U = 0) is one, its
phase is –180 deg.
Inv Smith
For "Inv Smith" formatted traces, the response values are interpreted as complex
reflection coefficients S
admittance Y(S
In a diagram, the grid lines overlaid to a "Smith" trace correspond to points of equal
conductance G and susceptance B:
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Points with the same conductance are located on circles.
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Points with the same susceptance produce arcs.
The following example shows an inverted Smith chart with a marker used to display the
stimulus value, the complex admittance Y = G + j B and the equivalent inductance L.
User Manual 1173.9163.02 ─ 62
and represented in terms of their corresponding complex
ii
) = G(S ) + j B(S ).
ii ii ii
Concepts and features
Screen elements
122