Rohde & Schwarz ZN-Z84, Руководство пользователя

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Application
R&S
®
ZN-Z84
31 User Manual 1319.5413.02 ─ 02
4 Application
From the perspective of the VNA, the purpose of a switch matrix is to extend the
number of test ports, i.e. to convert an N-port network analyzer into an N'-port
network analyzer (N'>N) without modifying the instrument itself. The increased
number of test ports can reduce or even eliminate the manual reconnections of
the DUT, resulting in a higher measurement speed, reliability and repeatability.
The firmware of the R&S ZNx family is able to control switch matrices from
Rohde&Schwarz directly. It is fast and easy to set up and operate a switch matrix
via the graphical user interface. For example, a R&S
ZNB in combination with a
R&S ZN-Z84 can seamlessly work as a multi-port network analyzer with up to 24
ports.
However, an N-port analyzer is always limited to measuring N signals simultane-
ously, i.e. during stimulation by the active test port, even though the DUT is fully
connected to the switch matrix, it may not be possible to measure all b-waves
simultaneously. For example, consider a DUT with 6 unbalanced ports, connec-
ted to a 2-port analyzer via the R&S
ZN-Z84 base unit without extension. For
each stimulus port, 5 sweeps are required to measure the resulting b-waves, 6·5
= 30 sweeps in total. For "real" 6-port analyzers, a single sweep per driving port is
sufficient.
Furthermore, in the example above, at least 6*5/2 successive matrix switching
procedures are required (one for each port pair). This involves command pro-
cessing and physical switching and hence might take some time to complete. To
optimize the measurement setup w.r.t. speed and resources, the characteristics
of the available switch matrices have to be taken into account.
●
Matrix support is not available for R&S ZNC and R&S ZND.
●
The Direct Control access to the R&S ZN-Z84 eliminates the protocol
and command processing overhead of the standard remote control
interfaces and hence significantly reduces the total switching time.
●
While it is allowed to connect multiple matrices to a single analyzer of
the R&S ZNx family, matrix cascading at RF layer is
not supported.