User`s guide

7-50
Operating Concepts
Measurement Calibration
Figure 7-38 Full Two-Port Error Model
A full two-port error model equations for all four S-parameters of a two-port device is
shown in Figure 7-39. Note that the mathematics for this comprehensive model use all
forward and reverse error terms and measured values. Thus, to perform full
error-correction for any one parameter, all four S-parameters must be measured.
Applications of these error models are provided in the calibration procedures described in
Chapter 5 , “Optimizing Measurement Results.”
Enhanced Response Calibration Error Model Enhanced response calibration uses
the same error model as the forward configuration portion of Figure 7-38. In the response
portion, the source and load match effects are fully-accounted for giving the same accuracy
to the forward tracking term (E
TF
) as the two-port calibration. During the measurement,
the enhanced response calibration performs a correction which is mathematically the same
as setting the values of E
LF
,E
LR
,E
SR
,E
XR
,E
DR
to zero (0) and the values of E
RR
and E
TR
to one (1) in the equations for S11 and S21 shown in Figure 7-39.