PCB Calculator | Microstrip - question about the "Ang_l" parameter

[Shmi]

Hi everyone,

I’m currently working on a RF PCB and I’m wondering about the “Ang_l” parameter in the PCB calculator (microstrip line).

Does it mean “Angle limitation” and therefore corresponds to the limit we set for our angles when routing ?

This may be a silly question, but I don’t want to make any mistakes.

Thank you for your answers !

Shmi

[johannespfister]

AFAIK: This is the phase angle shift a sine signal would have. Since the current has a limited speed, there is a phase shift between input and output. You calculate the angular difference.

[Shmi]

Hello johannespfister !

Thank you for your answer.

Is there a formula for calculating this parameter ? I found a lot of formulas on internet that I don’t think correspond to my needs.

Here’s my situation : I have to route 50 ohms lines on a little interposer made of alumina (thin film, 5 mm x 5 mm). To draw these lines, I only have a length of 0.610 mm.
Here are my settings :

Thanks again for your helpful answers!

Shmi

[johannespfister]

What frequencies do you use? If digital, what bus (keep in mind that for digital signals, the frequencies are way higher than the baud rate because the edges generate very high frequencies). 610µm doesn’t sound like this is any concern. Also not at the 9 GHz you choose in the image (assuming this is a 9 GHz sine wave or very similar to a sine wave).

It isn’t that hard to calculate. Calculate the propagation time of your track (in German i would call this Signallaufzeit, not sure what the correct translation is). And then you divide the period by that time times a full circle (360° or 2*π, whatever you prefer). But why do you want to calculate it by hand? KiCad does that for you.