Network Analyzer Calibration with Temperature

Hi,

Let say that I am doing S-parameter measurement on chip with several temperature point (-40C, 25C, 125C). Does the calibration need to be done only once at 25 or i need to recalibrate when I change the chuck temperature?. Thanks

obviously things change as the temperature change. But if you can insure that good contact is maintained over temperature, then the cal at 25 deg c is probably sufficient unless you are looking at very minute changes (like phase shift).

Probably a bigger thing to worry about is condensation on the chip when it goes cold. You would like to bathe the chip in N2, or some other inert gas, to keep water vapor from forming frost on the IC (which would cause a big circuit change).