Agilent Technologies 8753ET User Manual page 417

Figure 7-36 Load Match E
The measured value, S
21M
between E and S as well as E
SF 11A
device must be measured and stored for use in the S
calibrated as described for reflection to establish the directivity, E
frequency response, E , terms for reflection measurements on both ports.
RF
Now that a calibrated port is available for reflection measurements, the thru is connected and load match,
E , is determined by measuring the reflection coefficient of the thru connection.
LF
Transmission signal path frequency response is then measured with the thru connected. The data is
corrected for source and load match effects, then stored as transmission frequency response, E
NOTE It is very important that the exact electrical length of the thru be known. Most calibration kits
assume a zero length thru. For some connection types such as Type-N, this implies one male
and one female port. If the test system requires a non-zero length thru, for example, one with
two male test ports, the exact electrical delay of the thru adapter must be used to modify the
built-in calibration kit definition of the thru.
Isolation, E , represents the part of the incident signal that appears at the receiver without actually passing
XF
through the test device. See
configuration and with terminations installed at the points where the test device will be connected. Since
isolation can be lower than the noise floor, it is best to increase averaging by at least a factor of four during
the isolation portion of the calibration. The
menu allows a calibration sequence to resume after a change to the averaging factor.
If the leakage falls below the noise floor, it is best to increase averaging before calibration. In this case,
omitting isolation is better than measuring the isolation standards without increasing the averaging factor.
LF
, consists of signal components that vary as a function of the relationship
and S , so the input and output reflection coefficients of the test
LF 22A
Figure 7-37. Isolation is measured with the test set in the transmission
RESUME CAL SEQUENCE
error-correction computation. Thus, the test setup is
21A
, source match, E
DF
Operating Concepts
Measurement Calibration
, and reflection
SF
.
TF
softkey under the
Cal
7- 49