Welcome to n2pkvna Discussions!

[scott-guthridge]

👋 Welcome!

The N2PK Vector Network Analyzer is an open hardware test and measurement instrument N2PK VNA. Until now, the only software available for this instrument has been for Windows only and closed source. The goal of this project is to provide an open source alternative, more friendly to non-Windows users.

The Windows software is GUI based and mature. The initial version of this project, however, is only CLI based (fine for some, but not everyone), and supports only the dual port model v5 N2PK VNA with reflection bridge and manual port swap, i.e. it doesn't yet support the S-parameter test set, nor the RF IV set. We're currently working on adding support for the other hardware configurations.

We are looking for help in building a GUI, either as a script-based front-end to the existing CLI or as separate C code.

We welcome comments, questions and suggestions on this forum. Please feel free to join the discussion!

[scott-guthridge]

New release 0.1.1 adds a graphical user interface with manual plus support for other hardware configurations such as S-parameter test set and RF-IV board. Here's what's actually tested and not at this point.

Tested

• Reference frequency calibration
• Setup of reflection measurement only
• Setup of two-port VNA with reflection bridge on port 1 and manual DUT swaps
• SOLT calibration
• calibration with mix of built-in and custom standards
• DUT measurement
• Viewing the measurement in S, Z, Y, H, G, A, B, T & U parmeters, Zin, equivalent series/parallel RC/RL circuit & VSWR
• Saving the measurement
• Signal generator

Not Tested

• S-parameter test set
• RF-IV measurements
• 16-paramteter calibration with leaky test fixture

Please try it out. If you can help with testing, that would be great. Feedback (positive or negative) will be appreciated.

Scott

[scott-guthridge]

If you're using this code and would like to see something added or think something isn't right, please speak up and open an issue or start a discussion! Otherwise, I'll probably continue focusing on my other projects.

[akrpic77]

first, thank you for your project, you make it possible to do n2pk vna measurements without starting a virtual machine.

In the research phase of a project to control and use multi port test set together with n2pk vna, I've come to a conclusion that adding n2pk vna as a virtual instrument to the scikit-rf
would make the whole setup scriptable (together with missing control library for multi port test set).

libn2pkvna + python wrapper would already be half of the job for virtual instrument.

but looking at the code and Makefiles, I can't find a way to build just libn2pkvna. maybe can you make it possible to build just libn2pkvna as shared and/or static library?

[scott-guthridge]

The related library, libvna has a python front-end written in Cython (docs here: https://libvna.readthedocs.io/latest/). When building the python front-end, the build pulls in libyaml and libvna and builds everything. Then the "repair wheel" step of the build identifies the library dependencies and packages the needed libraries with the python module. So one can simply say pip install libvna and they get everything they need without having to install any packages outside of python.

Setting all this up is a little complicated, especially if you want to also support Windows and MacOS. I followed the example of SciPY, but simplified it quite a bit. If you're curious about this, here are some of the main files to look at. First two are part of the Cython front-end itself, and other three are main components of the build:

• cal.pxd
• cal.pyx
• pyproject.toml
• meson.build
• release.yml

But for the N2PK VNA, you need a bit more than just the libn2pkvna library. You also need the firmware files and the UDEV rules to load them. Python doesn't have a way to package these, so your users will have to install something outside of pip.

When you build RPM or Debian packages for n2pkvna, already the GUI is separated out into a separate install package. I could split it further so that there's a firmware+library package, a CLI package and a GUI package. But that makes the install slightly more complicated for others. Why not just install the n2pkvna package with the CLI. Even if you don't use the CLI, it doesn't take a lot of space, and it may be useful for debug. Also, you might consider building your python front-end on top of the CLI instead of on top of the library. This would provide higher level features like calibration and managing different hardware setups.

Anyway, installing the n2pkvna package with the CLI included is probably the simplest. Will that work for you?