vna-standards

OpenEMS simulation of VNA calibration standards. Read about this project at https://jmw.name/projects/vna-standards/

Setup and run directions

1. Download octave (or use Matlab) and OpenEMS. Ensure OpenEMS is on the octave/Matlab's path using addpath.
2. Run simulations for the standards via octave {open,short,load}_standard.m. The FDTD simulation will begin after the geometry preview window is closed. Generally, the simulations will not reach the end criterion of −50 dB in any reasonable amount of time. It is acceptable to terminate the simulation once the energy level has noticeably stopped decaying by running touch run/ABORT. The presence of this file will stop OpenEMS.
3. Generate comparison S11 charts using python plots.py. This script requires numpy and matplotlib.

Repository structure

• data_8714ES: S11 measurements of the standards on a 3 GHz Keysight 8714ES VNA.
• data_N5222B: S11 measurements of the standards on a 26.5 GHz Keysight N5222B VNA. At the time, only the 6 GHz calibration kit was available, so the data only extends to 6 GHz.
• docs: PDF datasheets for the Rosenberger connector used. The nominal dimension values are used in common_setup.m.
• Fitting.SLDPRT/Fitting.STL: the Solidworks part for the fitting cap used to enclose the SMA connectors, and a STL file appropriate for 3D printing. The opening is sized to nominal connector dimensions (.250") and may require adjustments for manufacturing and fitting.