R&S ZVB - Page 144

R&S
®
ZVA / R&S
®
ZVB / R&S
®
ZVT GUI Reference
Trace Menu
Operating Manual 1145.1084.12 – 30 129
Create new trace and select name and measurement parameter:
CALCulate<Ch>:PARameter:SDEFine "<Trace_Name>", "Y11" | "Y12" |
"Y21" | "Y22"
Stability Factor...
Opens a dialog to select one of the three two port stability factors K, μ
1
or μ
2
. Stability factors cannot be
calculated in balanced port configurations.
The Stability dialog provides the following settings:
 Stability Factor selects the stability factor to be calculated; see definitions below.
 Used Test Ports selects the test port number of the analyzer to be connected to the input (DUT
Input) and the output of the DUT (DUT Output). The stability factor calculation is based on 2-port
reflection and transmission S-parameters so that the input and output port numbers must be
different.
 The Port Topology panel is analogous to the corresponding panel in the More S Parameters
dialog. Stability factors can be calculated for unbalanced ports only. If a balanced port
configuration is selected, the analyzer generates an error message.
Values of any of the stability factors less than 1 indicate potential instability.
Definition of stability factors and stability criteria
The stability factors K, μ
1
and μ
2
are real functions of the (complex) S-parameters, defined as follows:
where denotes the complex conjugate of S.
Stability factors are calculated as functions of the frequency or another stimulus parameter. They provide
criteria for linear stability of two-ports such as amplifiers. A linear circuit is said to be unconditionally stable