Determination parasite capacities of resistance?

In hybrid microwave cicruit when resistance has been used so how can we determine its parasite capacities ? (attached figure....)
many thanks
N

C2 and C3 will be dominated by the pads of your test fixture - normally these can be deembedded if calibrated in TRL. If not you can estimate them from the C=epsilon*surface/thickness formula. Then what remains is C1, this can be extracted from the zero in your S21 measurement. This simple model will be adequate for most applications.