Hello,
Is there a way to generate an excel sheet that has the information for the all the traces net names, length and their line impedance in Kicad?
I am going to use this for my EMI analysis. I have seen other softwares generate such files such as Mentor PADS.
Please let me know,
Thanks
Yes and No…
The Inspect>Net_Inspector give some info.
Inductance, I calculate from my plugin. You can create the plugin from here (read the ‘more’ to get/include Inductance…
Example… I select the full board but can select individual/group of traces…
(FYI - If you know how to calculate Impedance, Peanuts and Banana’s, you can include those calc’s in the plugin…)
1 Like
It is not clear on what to do here. The link to knowledge is not working in youtube video. And it is not stated where to put .PY file.
There is No link in video. Just click ‘more’ to drop-down more info…
(the .py goes into the Scripting/Plugin folder…) but, info does say to get that location for the .py from Kicad forum…) Why? because location is not the same for all computer/platforms…
NOTE: This is Not an official Plugin and does not contain the Meta data/file/etc. Thus, you add it to the Scripting/Plugin folder (the older approach to plugin’s)
I unmarked your video as the “solution”, apparently the answer was not very clear:
That’s because OP didn’t read what I posted with the YouTube Video - not a shortcoming of my post, a shortcoming of a OP… either way, all the Info is in the YouTube Post if user wants to read what’s posted. The video also say’s in the 1st minute of text 'Learn Where To Put .PY File)
By the way, although that YouTube video has only 12 thumbs up, I’ve had messages from perhaps two dozen folks that had no problem and just wanted to know about adding other stuff to the Plugin… So, seems most folks do read…
AND let us get to practicalities here…
That information about trace length and impedance will do nothing for your EMI analysis. zero.
I’d suggest
a) a good knowledge of how to design for EMI (read any of Howard Johnson’s books) . Good basic design and layout rules will get you 99%.
b) measure it and see what the problems are. Use a sniffing toolkit (mix of E and H probes) and low cost Rigol SA.
c) If stuck perhaps enlist a field solver or someone with experience that can assist./ mentor .
glen - RF Engineer.
1 Like
@glenenglish is correct, a list of trace lengths and impedances tells you little for EMI analysis. You need field solver software to discover how these traces couple and a good understanding of the signals and loads. This becomes a very complex problem.
1 Like
I wonder what sort of analysis you are planning to do. Concering EMI trace length and impedance is closer to “zero” as glenenglish states then “litlle” (davidrsb’s answer)
A very important factor is loop area between a signal current in a track (trace), and it’s return path. Current always runs in loops. The first measure to reduce loop area is to add a good quality (non interrupted) GND plane. All signal currents with follow the path of least impedance. For DC this is the resistance, but for frequency content above a few kHz, inductance is the dominating factor, and (if possible) return currents will follow the same path in the GND plane as the signals through the signal tracks… And with a 4 layer PCB the distance between tracks and return current is reduced from around 1.6mm (PCB thickness) to around 0.2mm (Prepreg layer thickness) Rick Hartley (paid by our biggest competitor) has made some very good videos about this topic. Robert Feranec has also made a lot of video’s about this topic, and uses a field solver to visualize how the electromagnetic fields around PCB’s behave.
3 Likes
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.