Concepts and Features
R&S
®
ZNB/ZNBT
170
User Manual 1173.9163.02 ─ 55
●
(n – 1) one path two port calibrations for n calibrated ports (all possible 2-port com-
binations from the "Node Port" to any other port). The node port is the source port
for each one path two port calibration (fully calibrated port).
●
(n – 1) transmission normalizations (bidirectional, forward or reverse) for n calibra-
ted ports (all possible 2-port combinations from the first port to any other port).
"Forward" transmission normalization means that the signal direction is from the
ports with the lower numbers to the port with the higher numbers.
Example:
Select ports no. 1, 2, 3. A forward transmission normalization calibrates the S-parame-
ters S
21
, S
31
, and S
32
. A reverse transmission normalization calibrates the S-parame-
ters S
12
, S
13
, and S
23
. A bidirectional transmission normalization calibrates all six trans-
mission S-parameters.
5.5.5.3
Characterization of Calibration Units
Each calibration unit is delivered with factory characterization data which ensure an
accurate calibration for all standard applications. For specific modifications of the test
setup, e.g. the connection of additional adapters to a calibration unit, a modified set of
characterization data (suitable for the cal unit with adapters) may be desirable. The
R&S
ZNB/ZNBT provides a characterization wizard which you can use to generate
your own characterization data sets for (modified) R&S cal units. The characterization
data can be stored in the cal unit and used for automatic calibration whenever needed.
A cal unit characterization can be performed in a frequency sweep. The network ana-
lyzer must be properly calibrated, with the reference plane at the input ports of the
(modified) cal unit to be characterized.
The procedure involves the following steps:
1. Perform a calibration of your network analyzer, using the test setup and the calibra-
tion type you wish to perform with your calibration unit.
2. Connect the calibration unit to the network analyzer.
3. Access the "Characterize Cal Unit" dialog (CHANNEL – [CAL] > "Cal Devices" >
"Characterize Cal Unit...") and select "Start Characterization...".
4. Step through the "Characterization" wizard, following the instructions in the dialogs.
Dependency between calibration types and characterization data
A cal unit characterization provides full one-port (OSM) data at the selected ports plus
two-port (Through) data between any pair of selected ports. The measurement of
Through data is optional, however, it is required for some calibration types. The follow-
ing table gives an overview.
Calibration
