Smith Chart Format - Agilent Technologies 8753ET User Manual

Operating Concepts
Analyzer Display Formats

Smith Chart Format

The softkey displays a Smith chart format. Refer to Figure 7-9. This is used in reflection
SMITH CHART
measurements to provide a readout of the data in terms of impedance. The intersecting dotted lines on the
Smith chart represent constant resistance and constant reactance values, normalized to the characteristic
impedance, Z , of the system. Reactance values in the upper half of the Smith chart circle are positive
0
(inductive) reactance, and those in the lower half of the circle are negative (capacitive) reactance. The
default marker readout is in ohms () to measure resistance and reactance (R+jX). Additional marker types
are available in the Smith marker menu.
The Smith chart is most easily understood with a full scale value of 1.0. If the scale per division is less than
0.2, the format switches automatically to polar.
If the characteristic impedance of the system is not 50 ohms, modify the impedance value recognized by the
analyzer by pressing (the impedance value) .
Cal MORE SET Z0 x1
An inverted Smith chart format for admittance measurements is also available. This is shown in Figure 7-9.
Access this by selecting in the format menu, and pressing
SMITH CHART Marker Fctn
. The Smith chart is inverted and marker
MKR MODE MENU SMITH MKR MENU G+jB MKR
values are read out in siemens (S) to measure conductance and susceptance (G+jB).
Figure 7-9 Standard and Inverse Smith Chart Formats
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