Rohde & Schwarz 1145.1010.04/05/06, Operating Manual

Page: 191 / 813

R&S
®
ZVA/ZVB/ZVT Trace Menu
1145.1084.12 4.29 E-6
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 if no combination of passive source or load can cause the circuit to oscillate.
•
The K-factor provides a necessary condition for unconditional stability: A circuit is
unconditionally stable if K>1 and an additional condition is met. The additional condition can be
tested by means of the stability factors
µ
1
and
µ
2
.
•
The
µ
1
and
µ
2
factors both provide a necessary and sufficient condition for unconditional
stability: The conditions
µ
1
>1 or
µ
2
>1 are both equivalent to unconditional stability. This means
that
µ
1
and
µ
2
provide direct insight into the degree of stability or potential instability of linear
circuits.
References: Marion Lee Edwards and Jeffrey H. Sinsky, "A New Criterion for Linear 2-Port Stability
Using a Single Geometrically Derived Parameter", IEEE Trans. MTT, vol. 40, No. 12, pp. 2303-2311,
Dec. 1992.
Remote
control:
CALCulate<Ch>:PARameter:MEASure "<Trace_Name>", "KFAC21" |
"MUF121" | "MUF221" | ...
[SENSe<Ch/Tr>:]FUNCtion[:ON] "...:POWer:KFACtor | MUFactor1 |
MUFactor2"
Create new trace and select name and measurement parameter:
CALCulate<Ch>:PARameter:SDEFine "<Trace_Name>", "SY11" | "SY12"
| "SY21" | "SY22"
DC Inputs
The DC Inputs submenu selects DC voltages or the Power Added Efficiency (PAE) of an active two-port
DUT to be measured and displayed.