GUI Reference
R&S
®
ZNA
491
User Manual 1178.6462.02 ─ 12
If frequency converters are configured, the "Channel Base Power" at the RF IN port
can also show "varies", which either indicates that
are used or that a
source flatness calibration at the converter port is active. In the former case, the
combo-box is disabled. In the latter case, you can alternatively select P
b
or 0
dBm,
which deactivates the source flatness cal, or select "varies" to reactivate it.
Remote command:
SOURce<Ch>:POWer<PhyPt>[:LEVel][:IMMediate]:OFFSet
SOURce<Ch>:RLO:PABSolut
Port Power Offset ← Port Cal Power
Defines a port-specific offset to the
the port is equal to the "Channel Base Power" plus the "Port Power Offset".
If P
b
is selected as "Channel Base Power", then for a power sweep the actual port
power varies across the sweep. Otherwise the port power is constant.
Remote command:
SOURce<Ch>:POWer<PhyPt>[:LEVel][:IMMediate]:OFFSet
SOURce<Ch>:POWer<Pt>:ATTenuation:POFFset
SOURce<Ch>:RLO:POFFset
SOURce<Ch>:POWer<PhyPt>:GENerator<Gen>:OFFSet
Cal Power Offset ← Port Cal Power
For power calibrations only: Specifies a gain (positive values) or an attenuation (nega-
tive values) in the signal path between the source port and the calibrated reference
plane. With a "Cal Power Offset" of n
dB, the target power at the reference plane (cal
power) is equal to the actual output power at the port plus n
dB. The "Cal Power Off-
set" has no impact on the source power.
Example: Use of an amplifier in the signal path
Assume that a DUT requires a constant input power of +25
dBm, and that the mea-
surement path contains an amplifier with a 30
dB gain. After a reset of the analyzer, the
channel power P
b
is -10
dBm. Select a "Port Power Offset" of +5
dB at the calibrated
source port and a "Cal Power Offset" of +30
dB. Then the source power calibration
ensures that the constant input power of +25
dBm is maintained across the entire
sweep range. The actual output power of the analyzer is -5
dBm.
Notice that a power calibration with an appropriate "Cal Power Offset" can prevent
excess input levels at the DUT.
Remote command:
SOURce<Ch>:POWer<PhyPt>:CORRection:LEVel:OFFSet
SOURce<Ch>:POWer<PhyPt>:CORRection:GENerator<Gen>:LEVel:OFFSet
Reference Receiver Cal Power
Defines the source power the R&S
ZNA uses to perform the first calibration sweep of
the source power calibration. In this first sweep, the power meter reading is used to
calibrate the reference receiver of the calibrated port. The following calibration sweeps
are based solely on the reference receiver (see
Cal Softtool