Concepts and Features
R&S
®
ZNC
97
User Manual 1173.9557.02 ─ 13
Each offset parameter is assigned to a particular port. The delay parameters affect the
phase of all measured quantities related to this port; the loss parameters affect their
magnitude. An offset at port 1 affects the S-parameters S
11
, S
21
, S
12
, S
31
... Some quan-
tities (like the Z-parameters) depend on the whole of all S-parameters, so they are all
more or less affected when one S-parameter changes due to the addition of an offset
length.
To account for the propagation in both directions, the phase shift of a reflection parameter
due to a given length offset is twice the phase shift of a transmission parameter. If, at a
frequency of 300 MHz, the electrical length is increased by 250 mm (λ/4), then the phase
of S
21
increases by 90 deg, whereas the phase of S
11
increases by 180 deg.
Equivalent relations hold for the loss.
If the trace is displayed in "Delay" format, changing the offset parameters simply shifts
the whole trace in vertical direction.
The sign of the phase shift is determined as follows:
●
A positive offset parameter causes a positive phase shift of the measured parameter
and therefore reduces the calculated group delay.
●
A negative offset parameter causes a negative phase shift of the measured param-
eter and therefore increases the calculated group delay.
3.6.1.7
Offset Parameters for Balanced Ports
The offset parameters can be used for balanced port configurations:
●
Offset parameters must be assigned to both physical ports of a logical port.
●
"Auto Length" corrects the length offset of both physical ports of a logical port by the
same amount.
3.7 Optional Extensions and Accessories
The network analyzer can be upgraded with a number of hardware and software options,
providing enhanced flexibility and an extended measurement functionality. The available
options are listed in the "Info" dialog ("SETUP > Setup > Info..."). For a complete list of
options, accessories, and extras refer to the product brochure of your analyzer or to the
"Ordering Information" section of the R&S ZNC product pages on the internet.
The following sections provide an introduction to the software and hardware options
described in this documentation. The use of external power meters and generators does
not require any additional hardware or software options; it is described at the end of the
chapter.
Optional Extensions and Accessories
