Hello Everyone,

As part of my doctoral thesis, I am performing a 16-term calibration on structures with different load impedances. I have designed the load impedances with lumped RLC element. The idea is that after performing the 16-term calibration and de-embedding we should get the same load impedance i.e. calibration removes all the parasitic impedances of the structure.

I have added a image of the capacitance for a frequency range 1-110GHz. Before calibrating the load impedance was 2fF and after performing calibration and de-embedding the load is varying from 1-110 GHz frequency range. So my question is why is the load not constant over the frequency range? Why is the load capacitance smaller in the lower frequency. I performed it with different impedance of 2fF, 5fF, 10pH, 5pH, 100ohm, 20ohm etc. In all the cases load is not constant and its is smaller than the load impedance at lower frequency and higher at higer freqeuncy. If anybody has a knowledge about this subject, please share your views. It would be a great help for my further work. If you need any information you can ask me that too, I would be happy to share with you.

Cheers,

Jojo