Agilent Technologies 8753ES Option 011 Service Manual page 349

Error Terms
Full Two-Port Error-Correction Procedure
Error Term Descriptions
The error term descriptions in this section include the following information:
• significance of each error term
• typical results following a full 2-port error-correction
• guidelines to interpret each error term
The same description applies to both the forward (F) and reverse (R) terms.
Directivity (E and E )
DF DR
Description Directivity is a measure of any detected power that is reflected when a load
is attached to the test port. 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
reflection (S11, S22) of the load during the error-correction procedure.
Significant System Components
• load used in the error-correction (calibration)
• test port connectors
• test port cables
Affected Measurements
Low reflection device measurements are most affected by directivity errors.
Figure 11-2 Typical E /E without and with Cables
DF DR
Chapter 11 11-9