7- 46
Operating Concepts
Measurement Calibration
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
DF
, directivity, E
SF
, source match, and E
RF
, reflection frequency response, are computed and stored. See
Figure 7-32.
Figure 7-32 Open Circuit Termination
This completes the calibration procedure for one port devices.