GUI Reference
R&S
®
ZNC
268
User Manual 1173.9557.02 ─ 13
Cal Power Offset
For power calibrations only (not supported in the current firmware version): Specifies a
gain (positive values) or an attenuation (negative 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 Offset" 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 measure-
ment path contains an amplifier with a 30 dB gain. After a reset of the analyzer the channel
power P
b
is
–
10 dBm. With a "Port Power Offset" of +5 dB at the calibrated source port
and a "Cal Power Offset" of +30 dB, the source power calibration ensures that the con-
stant 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" will automatically
prevent excess input levels at the DUT.
Remote command:
Reference Receiver Cal Power
Defines the source power which the R&S ZNC 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
The accuracy of the source power calibration depends on the the power meter's mea-
surement accuracy, therefore it is advantageous to select a reference receiver cal power
at which the power meter provides a maximum accuracy. Otherwise your can use equal
port cal power and reference receiver cal power values.
Note: Risk of damage due to high power settings
If an external device (e.g. an amplifier) is connected between the calibrated test port and
the power meter, ensure that the reference receiver cal power does not exceed the max-
imum input power of this device.
Remote command:
4.4.3.14
Power Meter Transmission Coefficients Dialog
The "Power Meter Transmission Coefficients" dialog allows you to modify the scalar
power calibration data in order to account for an additional two-port device in the test
setup with known transmission coefficients. Configuration of the transmission coefficients
and activation are independent from each other.
Background information
Refer to
chapter 3.5.6.4, "Extended Test Setups"
Channel Settings
