Rohde & Schwarz 1145.1010.04/05/06, Operating Manual

Page: 375 / 813

R&S
®
ZVA/ZVB/ZVT Channel Menu
1145.1084.12 4.213 E-6
Port n Cal Power
The Port n Cal Power dialog defines the target power for the source power calibration. The settings are
port-specific.
The Port n Cal Power settings serve two different purposes:
•
Port Power Offset defines a port-specific offset to the channel power. The actual output power
at the port is equal to the channel power P
b
(Channel – Stimulus – Power) plus the Port Power
Offset. It is equal to the Port Power Offset (in dBm) if 0 dBm is selected instead of P
b
. For
power sweep and the selection P
b
, the actual port power varies across the sweep, for other
configuration the port power is constant.
•
Cal Power Offset 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 is equal to the actual output power at the
port plus n dB. The Cal Power Offset has no impact on the source power.
Use of an amplifier in the signal path
Assume that a DUT requires a constant input power of +35 dBm, and that the measurement path
contains an amplifier with a 30 dB gain.
After a reset of the analyzer the channel power P
b
is zero 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
constant input power of +35 dBm is maintained across the entire sweep range. The actual output power
of the analyzer is +5 dBm.
Note that a power calibration with an appropriate Cal Power Offset will automatically prevent excess
input levels at the DUT.
Remote
control:
SOURce<Ch>:POWer[:LEVel][:IMMediate]:OFFSet <numeric_value>,
ONLY | CPAD
SOURce<Ch>:POWer<Pt>:CORRection:LEVel:OFFSet
Receiver Power Cal...
Opens the configuration dialog for a receiver power calibration. The receiver power calibration data is
acquired in a calibration sweep after appropriate selection of the calibrated wave quantity and the
source.