Concepts and features
R&S
®
ZNB/ZNBT
194
User Manual 1173.9163.02 ─ 62
Calibration of S-parameters
S-parameters are not affected by a scalar power calibration. S-parameters are ratios of
incident and outgoing waves: for linear DUTs, they do not depend on the absolute
power. For measurements on non-linear DUTs, a SMARTerCal is recommended.
A SMARTerCal is also appropriate for frequency conversion measurements. For
detailed information, refer to
Table 4-13: Recommended calibration methods for various measurements
Measurement
System error correction Scalar Power calibration
SMARTerCal
S-parameter meas. on linear
DUTs
Yes
Not necessary
Not necessary
S-parameter meas. on non-lin-
ear DUTs
Not possible
--> Use SMARTerCal
Yes
Power (source) and meas. receiver, sup-
ported in combination with SMARTerCal
Yes
1)
Meas. of wave quantities or
ratios on linear DUTs
Not possible
--> Use SMARTerCal
Not necessary
Yes
Meas. of wave quantities or
ratios on non-linear DUTs
Not possible
--> Use SMARTerCal
Yes
Power (source) and meas. receiver, sup-
ported in combination with SMARTerCal
Yes
Power sweep, e.g. for com-
pression point measurement
Yes
Power (source): Yes
Meas. receiver: not necessary
Not necessary
Frequency conversion mea-
surements on linear DUTs
Not possible
--> Use SMARTerCal
Not necessary
Yes
Frequency conversion mea-
surements on non-linear DUTs
Not possible
--> Use SMARTerCal
Yes
Power (source) and meas. receiver, sup-
ported in combination with SMARTerCal
Yes
1) SMARTerCal is a multi-port calibration type. For one-port measurements, perform a
two-port SMARTerCal for a port pair including the measurement port.
In general, a power calibration involves two stages:
1.
Source power calibration:
An external power meter is connected to the calibra-
tion plane. The analyzer uses the power meter readings to calibrate its reference
receiver. Subsequently, it modifies its source power so that the calibrated reference
receiver reading corresponds to the desired source power value (flatness calibra-
tion).
Tip:
Since version 3.0 of the analyzer firmware, it is possible to perform the source
(flatness) calibration using the power meter (without previously calibrating the refer-
ence receiver).
This is particularly suitable for
receiver assigned to different VNA ports.
2.
Measurement receiver calibration:
The analyzer uses the calibrated source sig-
nal to adjust the power reading at the receive port.
Calibration
