Agilent Technologies 4395A, Ручное изменение

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Calibration for Network Measurement
Figure A -38. Load Match E
LF
The measured value , S
21M
, consists of signal components that vary as a function of the
relationship between E
SF
and S
11A
as well as ELF and S
22A
, so the input and output reection
coecients of the test device must be measured and stored for use in the S
21A
error correction
computation. Thus , the test setup is calibrated as described above for the reection to establish
the directivity , E
DF
, source match, E
SF
, and reection frequency response , E
RF
, terms for the
reection measurements .
Now , that a calibrated port is available for reection measurements , the THRU is connected and
load match, E
LF
, is determined by measuring the reection coecient of the THRU connection.
Transmission signal path frequency response is then measured with the THRU connected. The
data is corrected for source and load match eects , then stored as transmission frequency
response , E
TF
.
Isolation Errors . Isolation, E
XF
, represents the part of the incident signal that appears at the
receiver without actually passing through the test device (Figure A -39). Isolation is measured
with the test set in the transmission conguration and with terminations installed at the points
where the test device will be connected.
Figure A -39. Isolation E
XF
Error T erms the 4395A Can Reduce . Thus there are two sets of error terms , forward and
reverse , with each set consisting of six error terms , as follows:
F orward
Directivity , E
DF
Isolation, E
XF
Source Match, E
SF
Load Match, E
LF
Transmission Tracking, E
TF
Basic Measurement Theory A-55