Agilent Technologies 8719ES User Manual page 415

Operating Concepts
Measurement Calibration
Figure 7-30 Measured Effective Directivity
Next, a short circuit termination whose response is known to a very high degree is used to
establish another condition as shown in Figure 7-31.
Figure 7-31 Short Circuit Termination
The open circuit gives the third independent condition. In order to accurately model the
phase variation with frequency due to fringing capacitance from the open connector, a
specially designed shielded open circuit is used for this step. (The open circuit capacitance
is different with each connector type.) Now the values for E , directivity, E , source
DF SF
match, and E , reflection frequency response, are computed and stored. See Figure 7-32.
RF
7- 45