Bonzo , this is a different concept. I say reference plane because is the way to define the measurement point. Its clear that the wavelength is bigger than normal working dimensions in this case , but the problem are the accuracy of measurement and the parasitic components, you can for example add a fixed 100pF capacitor at the VNA port and then perform the OSL calibration after that, over the fixed capacitor you connect another capacitor let 100pF the VNA will measure close to 100pF ignoring the fixed value. This is the VNA calibration. If you use 2 ports to perform a good measurement you need to perform a FULL 2 PORTS calibration to completely define the reference planes or the connection points. Many nanovna has a only 2 parameters , in this case I recommend to use only one port (port 1 ) very good calibrated.
Other example is a RLC meter , you have an open and short definition to calibrate the instrument and lambda is kilometric… you need to null the parasitic components prior to measure.
Again, all depends on your accuracy requirements.

Regards, Patricio.


Ing. Patricio A. Greco
Laboratorio de Calibración ISO 17025 AREA: RF/MW
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