Rohde & Schwarz R&S ZNA Series - 4.5.1.12 Complementary isolation measurement

Concepts and features
R&S
®
ZNA
198User Manual 1178.6462.02 ─ 29
To establish a sufficient set of Through connections, you can select an arbitrary test
port as the "center" and measure all Through connections to this test port ("star-sha-
ped calibration"). You can also connect all ports in increasing order, e.g. 1→2, 2→3,
3→4 ...
[For the mathematically inclined: the graph constructed from the calibration ports as
nodes and the measured Throughs as edges must be connected.]
If an external switch matrix is configured and you want to calibrate three or more test
ports that are all on the same submatrix, then an extra Through measurement is
required: Complement the minimum set of n-1 Throughs (as explained above) by an
additional Through at a port pair that is connected by a "chain of throughs" of length 2
(e.g. between ports 2 and 4 in the examples above).
See Chapter 4.7.41, "External switch matrices", on page 323 for background informa-
tion on switch matrices and their submatrices.
Compared to the full number of n(n-1)/2 Through connections, the time and effort is
significantly reduced, in particular if n is large.
The "Reduced Through" logic is implemented for all full n-port calibration types.
●
During manual calibration, you can apply the calibration when a sufficient set of
Through connections have been measured. However, you can measure additional
Through connections to improve the accuracy.
●
If Multiple port assignments are required, an Automatic calibration always proposes
a minimum number of port assignments. However, for each port assignment all
possible through connections are measured by default. If you want to apply the
"Reduced Through" logic also for each port assignment, you can activate it in the
system configuration.
4.5.1.12 Complementary isolation measurement
For each port pair in a manual transmission normalization or TOSM calibration, the
Through measurement can be complemented by an isolation measurement. This mea-
surement accounts for possible crosstalk between the related test ports (e.g. on a test
fixture).
Calibration