step discontinuity

Hi Ppl,

Does anybody have material (or references) about step discontinuity
in microstrip.

I need formula that calculates values of the model,based
on actual properties of the discontinuity - such as :
width1,width2 substrate height ...

(step discontinuity model - 2 series inductors and capacitance to the
ground between the inductors)

Thank you in advance,


Gosha

Step discontinuity is automatically some shunt (parasitic) capacitance being instroduced.

You can ignore them at some level, rule of thumb I have learned is below 3GHz.
You can compesate this by impedance matching to Z0 value adding something extra (e.g. a stub etc.) to the microstrip line.

The least you can approach this by using some tool like LineCalc having to approxiamte what that value would be in real world. You know the material you are using or will use.

Hi GoaGosha,

this should be the set of equations you are looking for.

flyhigh

Thank you,

flyhigh - it's the material I meant.

djalli - since relevant data is up to 6 GHz and I have to extract
model precise as much as I can (for basic structures)
I need to know how much this phenomena can effect
values in model.
You said something about LineCalc -
Have you meant the one in @DS ?
I didn't quite understand how could I use the above for
extracting the model parameters ?

Thank you again :) ,

Gosha