Agilent Technologies HP 8719D Service Manual page 322

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
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.
important component. The test port connector, the cable, and the coupler also
greatly affect the measured directivity error.
Affected Measurements.
errors are measurements of low reflection devices; highly reflective device
measurements
will appear normal.
*
cc.
Figure 11-l. Typical EDF/EDR Without Cables
The load used in the calibration is the most
The measurements most affected by directivity
Error Terms
1 l-8