Agilent Technologies 8719D, User Manual

Page: 337 / 673

Figure 6-39. Measured Effective Directivity
Next, a short circuit termination whose response is known to a very high degree is used to
establish another condition (see Figure 6-40).
l
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, , source match, and
reflection frequency response, are computed and stored (see 6-41). This completes the
calibration procedure.