7- 51
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.