Rohde & Schwarz ZNB20, User Manual

Page: 182 / 1332

Concepts and Features
R&S
®
ZNB/ZNBT
167 User Manual 1173.9163.02 ─ 38
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 172.
Table 4-11: 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 refer-
ence receiver reading corresponds to the desired source power value (flatness cal-
ibration).
2. Measurement receiver calibration: The analyzer uses the calibrated source sig-
nal to adjust the power reading at the receive port.
Calibration