Rohde & Schwarz 1145.1010.04/05/06, Operating Manual

Page: 176 / 813

Trace Menu R&S
®
ZVA/ZVB/ZVT
1145.1084.12 4.14 E-6
Port assignments of the DUT and the analyzer
S-parameters S
<out>< in>
characterize the Device Under Test, so the indices <out> and < in> denote the
output and input ports of the DUT. Analogously the waves a
1
and a
2
are referred to as incident waves,
b
1
and b
2
to as outgoing waves.
The analyzer measures the waves a
1
, b
1
, ... at its own test ports in order to obtain S-parameters, ratios
and other derived quantities. The test ports of the analyzer are numbered, so it is convenient to use
them as a reference, defining port number n of the DUT as the port connected to test port n of the
analyzer. With this convention the waves a
n
and b
n
have the following meaning:
•
a
n
is the wave transmitted at test port no. n of the analyzer (stimulus signal) and fed to port
number n of the DUT (incident wave).
•
b
n
is the wave transmitted at port number n of the DUT (response signal) and received at test
port no. n of the analyzer (received wave).
The analyzer offers various diagrams and display formats to visualize the results. The analyzer
places no restriction on the formats that are available for each measured quantity. However, to
keep the interpretation simple, it is recommended to select an appropriate display format; see
Trace - Format.
S11, S12, S21, S22
Select one of the four elements of the standard 2-port scattering matrix (S-parameters).
The S-parameters are the basic measured quantities of a network analyzer. They describe how the
DUT modifies a signal that is transmitted or reflected in forward or reverse direction. S-parameters are
expressed as S
<out>< in>
, where <out> and <in> denote the output and input port numbers of the DUT.
A full 2-port S-parameter measurement involves 2 stages (referred to as partial measurements) with
interchanged drive and receive ports. The analyzer automatically switches the internal power sources
and the receivers to obtain the desired S-parameters
.
Remote
control:
CALCulate<Ch>:PARameter:MEASure "<Trace_Name>", "S11" | "S12" |
"S21" | "S22"
[SENSe<Ch/Tr>:]FUNCtion[:ON] "...:POWer:S<11 | 12 | 21 | 22>"
Create new trace and select name and measurement parameter:
CALCulate<Ch>:PARameter:SDEFine "<Trace_Name>", "S11" | "S12" |
"S21" | "S22"