Hi all,
I’m a newbie in Kicad forum and I have a problem when I try to calculate track wide antenna 2.4GHz for layout a wifi board. Specially, when I use “Coplanar wave guide with ground plane” of PCB calculator tool in KIcad to calculate track wide (W) with “Electrical Parameter” Z0=50 Ohm, it gives me a result W = 0.533994 mm
Parameters like this picture:
But I received another result from tools in websites online and almost them gived me a result that W = 0.92 or around 0.92
I cannot understand why having that diffrence between tool from kicad and tool from websites online
Please give me a advice or explanation for my issue
Thanks all
Those websites are probably assuming that your copper thickness is 1oz copper. That translates to about 0.035mm. You have more than 2oz of copper thickness in your calculation, which throws the impedance off.
If you adjust T to match the website value, you will have a close agreement with KiCad.
I find a close match with the sites that I use.
T hardly matters unless S is very small, which yours is, there will be some tolerance problems.
FR4 Er for 2.4GHz won’t be 4.6 either
Hi @davidsrsb,
I’m starting to study about antenna so I don’t really understand about your comment
Can you give me some advices or documents about this field
Thanks ^^
A gap of 0.2mm is so small that the PCB tolerances be important. It might actually be 0.18mm or 0.22mm or worse.
I presume that with Er=4.6, you are planning to use standard FR4 material. As frequency goes up, FR4 Er falls.
There is also variability between suppliers. http://www.av.it.pt/Medidas/index.php?option=com_content&view=article&id=54&Itemid=60
