Agilent Technologies E5071C Manual page 474

Parameter when measuring a balanced - balanced device
(Imbalance1, Imbalance2)
Parameter when measuring a single-ended - single-ended -
balanced device (Imbalance1, Imbalance2, Imbalance3,
Imbalance4)
The balance matching circuit (Differential matching circuit
•
embedding) is not applied to single-ended S-parameter results.
For example, the balance matching circuit is not applied to the
Measurement
473