How to buy a cheap calibration kit. When using a VNA or network analyzer, you will need a “cal kit” (calibration kit) to calibrate away any effects of cables, connectors, etc. that are not part of what you are trying to measure.
For some odd reason, official calibration kits are fairly expensive. But the guys at HHF – Heuermann HF-Technik GmbH have found a cheap and pretty good alternative solution if you can live with something that works up to 5GHz only. They present the solution here along with some measurements to show how it works:
The “kit” basically consists of 3 specific Rosenberger part numbers (the 50R load 32K15R-001E3, the “through/open” 32Z114-000L5 and the short 32K101-K00L5).
Along with the 3 parts, the corresponding parameters need to be entered into the network analyzer. All C- and L-coefficients can be set to zero. The offset lengths are set as shown.
- The Load (Rosenberger 32K15R-001E3): 0 mm offset length.
- The Open (Rosenberger 32Z114-000L5): 7 mm offset length.
- The Through (same part): 0 mm offset length.
- The Short (Rosenberger 32K101-K00L5): 1.96 mm offset length.
Using this little trick to get a decent and cheap calibration kit can easily save you EUR 10K. It should cost you less than EUR 100 to buy these three parts from Rosenberger – shipping included. Send your thanks to HHF – Heuermann HF-Technik GmbH. Great tip.
Note: Using a calibration kit is not really needed if you are doing PDN measurements using a VNA as described in this video.