Impedance in microstrips

I have calculated line capacitance through variational method using equations,please tell me how to calculate impedance ?Any equation realting line capacitace and impedance?

I think you may have your answers from:
at the book:
Microstrip antenna Design Hand book - (appendix B).
related link:
http://www.megaupload.com/?d=P3OOKDB3

and your second one:
It's can be found at chapter II - Microwave Engineering, David M. Pozar.

Have fun!

http://chemandy.com/calculators/micr...calculator.htm

Thanks vfone but in that calculator they are not calculating impedance though line capacitance,I want equatioon which can relate line capacitance to impedance.

Zo = √(L/C)

Hi,

Take note that equation above is valid for uncoated trace or copper, PCB manufacturer normally cover the trace or copper with mask with a thickness of 8-10 mills and that will turn the equation to;


er' = er{ 1 - pow(e, ((-1.55*(H+T+M))/H) ) }
where
e =euler's constant
H =Trace distance from a ref plane
T =Trace thickness
M =Mask thickness

and it will effect if you're implementing controlled impedance where;
Zo = (79/sqrt(er'+1.41))*ln(5.98*H/(0.8*(W+T)))Ω valid for 5<W<15 mills
or
Zo = (87/sqrt(er'+1.41))*ln(5.98*H/(0.8*(W+T)))Ω valid for 15<W<25 mills

And also take note that this 2 equation is accurate to ±5% when W to H ratio is less than 0.6, when the ratio rise from 0.6 or more, accuracy typically drop to ±20%.

and the intrinsic capacitance is;
Co = (1.41*er')/ln(5.98H/0.8(W+T)

You may refer to IPC-D-317A for more literature.


Goodluck...

Hi,

Check this http://imodelit.com/ViewDetails.aspx?AID=142

Best Regards,
imodelit Moderator

You should also calculate by variational method the line inductance.

Thank you all of you but i have found the answer in one of the papers of great Yamashita,if any wants that can tell to me

pareshatlnmiit:

Please send link or upload that article.

"This paper has already been attached",message comes when i am attaching this paper so i m sending u link you can see from there and if you have any query regarding this topic ,ask me i have already finishes with the equations of this paper
Here is the link
https://www.edaboard.com/viewtopic.php?p=581131#581131

i am not able to download from megaupload..can u upload on rapidshare

Akedar tell me the way,i will upload on rapidshare.