Agilent Technologies 4395A, Manual Change

Page: 428 / 575

Calibration for Network Measurement
Figure A -32. Measured Eective Directivity
Next, a SHORT termination whose response is known to a very high degree establishes another
condition (Figure A -33).
Figure A -33. Short Circuit T ermination
The OPEN gives the third independent condition. In order to accurately model the phase
variation with frequency due to radiation from the OPEN connector , a specially designed
shielded OPEN is used for this step . (The OPEN capacitance is dierent with each connector
type). Now the values for E
DF
, directivity , E
SF
, source match, and E
RF
, reection frequency
response , are computed and stored (Figure A -34 ).
A-52 Basic Measurement Theory