8719ET/20ET/22ET
Error Terms
8719ES/20ES/22ES
Error Term Descriptions
RF Network Analyzers
Directivity (EDF and EDR)
These are the uncorrected forward and reverse directivity error terms of the system. The
directivity error of the test port is determined by measuring the S11 and S22 reflection of
the calibration kit load. The load has a much better return loss specification than does the
uncorrected test port, therefore any power detected from this measurement is assumed to
be due to directivity error.
Significant System Components. The load used in the calibration is the most important
component. The test port connector, the cable, and the coupler also greatly affect the
measured directivity error.
Affected Measurements. The measurements most affected by directivity errors are
measurements of low reflection devices.
Figure 11-1 Typical EDF/EDR without Cables
Service Guide
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