Keysight N5221A Service Manual page 314

General Purpose Maintenance Procedures
Error Terms
Figure 8-3 Flowgraph of Three-Port Error Terms
where:
E = error term
DIR = Directivity
MAT = Forward Source Match and Reverse Load Match
TRK = Forward Reflection Tracking and Reverse Transmission Tracking
For the case of a full 3-port calibration, port 1 has
three Match error terms:
S11 source match
S12 load match
S13 load match
and three Tracking error terms:
S11 reflection tracking
S12 transmission tracking
S13 transmission tracking
There are six isolation terms not shown.
8-6
PNA Series Microwave Network Analyzers
Service Guide N5222-90001
N5221A/22A