R&S ZNB Series User Manual page 217

®
R&S ZNB/ZNBT
Balun
In contrast to standard balanced embedding (4-port), the matching circuit is only
applied to the differential mode port (2-port). It can be specified via a Touchstone s2p
file or by parametrizing a lumped "Shunt L, Shunt C" element model.
4.6.2.9 Fixture modeling and deembedding
When performing tasks such as verifying digital high-speed signal structures on printed
circuit boards (PCBs), measurements have to be carried out on certain layers without
the effects of probes, probe pads, vias, lead-ins and lead-outs. This requires the use of
accurate deembedding algorithms to calculate and remove these effects from the mea-
surements, leaving only the result for the area of interest.
Instead of asking the user to define the fixture by parametrizing one of the given lum-
ped circuit models or by "somehow" providing a suitable snp file, the firmware of the
R&S ZNB/ZNBT now also provides integration for third-party tools that model the test
fixture from measured data:
●
AtaiTec's
●
PacketMicro's
●
Eazy de-embedding based on IEEE 370
The tools are integrated into the deembedding functionality of the R&S ZNB/ZNBT
firmware. More fixture modeling tools may be added in future firmware releases.
Test Setup
The setup below shows an example for verifying the high-speed differential signal lines
on a PCB.
User Manual 1173.9163.02 ─ 62
Differential Matching Network
L
G
R
In-situ de-embedding (ISD)
Smart fixture de-embedding
Offset parameters and de-/embedding
C
(SFD)
Concepts and features
217