Microwave connector - maximum operating freq.

Hi,

I've seen 3.5 mm connectors work up to 67 GHz (the one used in Agilent E8361A VNA).
But I've not seen N-type connectors which are used in equipment work above 10 GHz.

Is there a maximum operating frequency for a microwave connector (say 2.4 mm, 3.5 mm, K-type, N-type) due to it's geometry?

What decide the maximum operating frequency of a connector?
geometry or the material which is used to make it?

cheers,
per_lube

the most obious thing is the inner diameter-if it is too big waveguide modes can propagate in addition to the mode on the coaxial cable. that would be bad

there is a N connector that works to 18 ghz. It has a special inside shield connection to reduce the maximum internal diameter.