At which frequency we chose dielectric constant

engr_david_ee

Joined Mar 10, 2023
205
If I have a digital signal of 1 GHz clock frequency. How do I chose the dielectric constant value of the dielectric material ? Do I need to look for the dielectric constant value at 1 GHz ? I don't think so because 1 GHz is not the bandwidth.

I understand that bandwidth of a digital signal is related to rise time or edge rate but if I do not have that information with me then how do I estimate the bandwidth for a given digital signal having clock frequency 1 GHz.

I guess it is the bandwidth of the signal at which I need to chose dielectric constant value, right ?

crutschow

Joined Mar 14, 2008
34,855
I understand that bandwidth of a digital signal is related to rise time or edge rate but if I do not have that information with me then how do I estimate the bandwidth for a given digital signal having clock frequency 1 GHz.
You could start by estimating a value of about 1/10th the digital signal period for the rise/fall times, which would be 0.1ns.
The approximate bandwidth of that is 0.35/0.1ns = 3.5GHz.
That value should be in the ballpark of the highest frequency of interest.