Keysight N5221A Service Manual page 313

PNA Series Microwave Network Analyzers
N5221A/22A
Figure 8-2 Flowgraph of Two-Port Error Terms
where:
E = error term
1st Subscript:
D = Directivity
S = Source Match
R = Reflection Tracking
X = Crosstalk (Isolation)
L = Load Match
T = Transmission Tracking
2nd Subscript:
F = forward measurement (Ports 1 to Port 2)
R = reverse measurement (Ports 2 to Port 1)
Service Guide N5222-90001
General Purpose Maintenance Procedures
Error Terms
8-5