R&S
®
ZVA / R&S
®
ZVB / R&S
®
ZVT GUI Reference
Channel Menu
Operating Manual 1145.1084.12 – 30 371
For mixer noise figure measurements (option R&S ZVA-K31), a 50 kHz IF bandwidth is used, and
the low phase noise mode is activated.
Sequential versus Simultaneous measurement
During the noise figure measurement stage, the analyzer must determine the power levels of the CW
signal and of the noise signal at the output of the DUT (P
Signal, 2
, P
Noise, 2
). This may be done in a single or
in two measurement stages.
In Sequential mode, the noise power and the CW signal power are measured in two consecutive
sweeps. The first step consists of a normal gain measurement. In the second step the source CW
power is reduced to obtain the noise power from the AVG and RMS detector values.
Advantages: This mode provides accurate results over a wide range of source power levels. In
general, no additional external equipment (attenuator) is needed.
Shortcoming: Increased (doubled) measurement time.
In Simultaneous mode, the noise power and the CW signal power are measured in a single sweep
using two different detector settings.
Advantages: Shortest measurement time; the noise figure of the DUT is measured under normal
operating conditions.
Shortcoming: Higher source noise. For accurate results the input power at the DUT should be in
the range between approx. –70 dBm and –50 dBm. For network analyzers without generator step
attenuators, an external attenuator is required.
[SENSe<Ch>:]SWEep:DETector:TIME
[SENSe<Ch>:]NFIGure:SEQuential
[SENSe<Ch>:]NfIGure:RFICorr
[SENSe<Ch>:]NfIGure:NDUT
Noise Figure Cal...
Opens a dialog to assess and compensate the internal noise at the NWA receiver and source. The noise
figure calibration should be performed after regular power calibration using an external power sensor
following the instructions in section Power Calibration. It is required for various reasons (see also Basic
Test Setup and Noise Figure Calculation):
The Receiver Noise Calibration determines the noise figure of the internal NWA receiver and
ensures an accurate measurement of the output signals P
Signal, 2
, P
Noise, 2
.
The Source Noise Calibration determines the noise figure and gain of the internal NWA source
and provides the accurate source signal contributions P
Signal, 1
, P
Noise, 1
.
If an additional external attenuator is used (see Sequential vs. Simultaneous measurement), the
noise contribution of this attenuator must be compensated in addition. The same applies if the
Gen Atten for Src NCal and Gen Atten for DUT Meas settings differ from each other.
The necessary calibration steps are automatically performed with the channel settings of the active noise
figure measurement.
Noise figure calibration procedure
The noise figure calibration is performed in two steps. A third step is added if an external attenuator is
used.
1. Receiver noise calibration of the analyzer's receive port. The receive port (assigned to the DUT output)
is terminated with a 50 Ω match. The connecting cable for the DUT should also be used to connect the
match. If a pre-amplifier (preferably, the low-noise preamplifier R&S ZVAX-B203) is used for the
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