I picked up a cheap Anritsu 22N50 male N-type open/short recently. Apparently these were meant to be used mainly with the Site Master (scalar) antenna analyzers, but they are listed as an accessory for some VNAs as well. It looks like a decent design, with precision 18GHz N connectors and an open with an extender pin (instead of just a shield). Unfortunately, there doesn't seem to be a datasheet with standard definitions.
When you select the predefined N (m) calibration kit on an Anritsu VNA, it will use the following definitions:
Open: offset 17.83mm, C0=4e-15 F, C1=200e-27 F/Hz, C2=0 F/Hz^2, C3=1.1e-45 F/Hz^3
Short: offset 17.83mm, L0=0, L1=0, L2=0, L3=0
This will probably give reasonable results, but I wonder if anyone here has actually measured one of these?
