Agilent Technologies 4395A - Page 428

Calibration
for
Network
Measurement
Figure
A
-32.
Measured
Eective
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 dierent with each connector
type). Now the values for E
DF
, directivity
,E
SF
, source match, and E
RF
, reection frequency
response, are computed and stored (Figure A
-34).
A-52 Basic Measurement Theory