Isolation - HP 8753E User Manual

In total, ten measurements are made, resulting in ten independent equations. However, the
TRL error model has only eight error terms to solve for. The characteristic impedance of the
line standard becomes the measurement reference and, therefore, has to be assumed ideal (or
known and defined precisely).
At this point, the forward and reverse directivity (Enr and Enn), transmission tracking (Err
and Em), and reflection tracking (Em and E
terms. This leaves the isolation (EXF and ExR), source match (Esr and Esn) and load match
Two additional measurements are required to solve for the isolation terms (EXF and ExR).
Isolation is characterized in the same manner as the Full 2-port calibration. Forward and
reverse isolation are measured as the leakage (or crosstalk) from port 1 to port 2 with each port
terminated. The isolation part of the calibration is generally only necessary when measuring
high loss devices (greater than 70 dE8).
Note
same during the isolation calibration and the measurement.
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Figure 6-53. S-term TRL error model and generalized coefkients
Application and Operation Concepts
) terms may be derived from the TRL error
RR
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I
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I
RR
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