User`s guide

7-44
Operating Concepts
Measurement Calibration
Figure 7-29 "Perfect Load" Termination
Since the measured value for directivity is the vector sum of the actual directivity plus the
actual reflection coefficient of the "perfect load," any reflection from the termination
represents an error. System effective directivity becomes the actual reflection coefficient of
the near "perfect load" as shown in Figure 7-30. In general, any termination having a
return loss value greater than the uncorrected system directivity reduces reflection
measurement uncertainty.
Figure 7-30 Measured Effective Directivity