Hi
i want to measure the rise/fall time for a diode that is a zero bias schottky diode.the Low parasitic impedance is less than .05 pF.can anyone help me to measuring,please?
you are right.but here there are some problems.
1)i just have a datasheet.i dont have the diode.
2)this diode must work in rf frequency such as 10GHz.
tanx!
no if it was in datasheet i would find it.i need an equation between junction capacitance and tr.model of the diode is SMS7630-061.if you can say the order of tr considering the Cj is enough for me.
I don't have exact idea about that formula; in your first post you have mentioned that "measure the rise/fall time" and asked help for measuring it; However you exact requirement is to define the formula.
The rise fall time of the diode is a combination of the actual diode physics, its "dynamic resistance", and the load (especially any capacitance) you will have. Since you need to lowpass filter the output (so that the microwaves do not leak out), there will always be some capacitance. You can try to model that all in something like spice.
You will find that fall time is greatly influenced by the resistive load chosen.