Trouble in VNA calibration

I set the frequency range from 5G to 10G and operate the standard 1 port calibration (SOL), using the standard calibration kits.
I happened to see the strange display:
When I re-connect the "open" calibration kit I used before, the display is not a point or even a short line around the open point in Smith chart (1,0). It is a curve from exp(j*-90degree) to exp(j*-160degree);
When connect the "short" kit, it display a curve from exp(j*90degree) to exp(j*20degree);
The only correct one is "load" , concentrate at (0,0).

Can someone help me and explain it,or something wrong in my calibration?

I know its kind of a pain in the butt, but have you tried a two-port cal (even though you're using one port). It should give you a bit more information to work with.

That's a really large frequency range. Have you considered cal'ing the vna for smaller increments?


best regards,

asd