Rohde & Schwarz R&S ZNA Series - Page 219

Concepts and features
R&S
®
ZNA
219User Manual 1178.6462.02 ─ 29
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 Chapter 4.5.7, "SMARTerCal", on page 224.
Table 4-14: 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
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: It is also possible to perform the source (flatness) calibration using the power
meter (without previously calibrating the reference receiver).
This is particularly suitable if a source and a reference receiver from different VNA
ports are combined via Direct generator/receiver access (and redefined physical
ports).
2. Measurement receiver calibration: The analyzer uses the calibrated source sig-
nal to adjust the power reading at the receive port.
Calibration