Concepts and features
R&S
®
ZNB/ZNBT
277
User Manual 1173.9163.02 ─ 62
The plug-in interface allows the external software to interact with the firmware before
and after a change of the:
●
channel
●
drive port
●
sweep segment
●
sweep point
The plug-in then can perform arbitrary actions and eventually return data to the VNA
firmware:
●
as custom traces
●
as input values for math functions for the calculation of other traces
To calculate a custom trace, the plug-in can make use of all data access points in the
channel calculation chain. See
Chapter 4.1.5.1, "Channel data flow"
Furthermore, it can communicate with other processes / peripherals that are not part of
the VNA firmware or host OS.
4.7.30.1
Basic use case
A basic use case is the integration of a power supply into an arbitrary VNA sweep.
Suppose that you want to test an amplifier with various bias settings. To do so, you can
perform a CW sweep to measure S-parameters with different gate voltages applied to
the amplifier at each sweep point.
With one power supply channel connected to the amplifier’s gate, and another channel
connected to the amplifier’s drain, the measurement could proceed as follows:
1. At the beginning of the sweep, the power supply is initialized (e.g. voltage setting
and current limit for each power supply channel) and then switched ON.
2. At the beginning of each sweep point, the plugin sets the power supply gate volt-
age to the next value.
3. At the end of each sweep point, the plugin reports the power supply reading of the
gate voltage and drain current to the VNA. These readings are displayed in dedica-
ted traces.
4. At the end of the sweep, the power supply is switched OFF.
4.7.30.2
Technology
The plug-in interface is a traditional C style DLL interface. Suitable DLLs can be com-
piled using different platforms, such as C or MATLAB. A plug-in is installed in the firm-
ware as a
*.zip
file, containing the external DLL and, possibly, additional files to be
kept with the DLL.
An SDK for external DLLs is provided with the analyzer firmware on the Rohde&
Schwarz internet pages.
Optional extensions and accessories