Concepts and Features
R&S
®
ZNB/ZNBT
203
User Manual 1173.9163.02 ─ 38
4.7.3 Mixer and Frequency Conversion Measurements
Option R&S
ZNB/ZNBT-K4
With option R&S
ZNB/ZNBT-K4, the frequencies, source powers and receiver levels of
the analyzer test ports can be configured independently. The source and receive fre-
quencies of the ports are always equal. Arbitrary port settings represent a major exten-
sion to the analyzer's measurement functionality; in particular they allow you to perform
measurements on frequency-converting DUTs.
The following figure shows a transmission measurement on a mixer.
To perform the measurement, the port frequencies must be set appropriately. In the
port configuration table ("CHANNEL > CHANNEL CONFIG > Port Config > Port Set-
tings... > Arb Frequency"), the (source) frequency of Port 1 is set to the desired RF fre-
quency (here: the channel base frequency/sweep range f
b
). An external generator pro-
vides a fixed stimulus signal at 1 GHz. To measure the up-converted IF signal, the
(receive) frequency at Port 2 is set to f
b
+ 1 GHz. Independent source powers for Port 1
and Gen1 may be configured in addition, if so desired.
In the example above, the transmission parameter S
21
corresponds to the mixer's con-
version gain.
Internal Second Source
If an internal second source is available, the mixer measurements outlined above (and
many other measurements) can be performed without an additional external generator;
see
Chapter 4.7.7, "Internal Second Source"
on page 212. However, be aware of the
limited source connectivity (described there).
Optional Extensions and Accessories
