FEDEVEL
Platform forum

Pixel , 08-15-2022, 03:48 AM

Hi,
I have a question for one of the PCB patch antenna for WiFi and Bluetooth videos

Why Eeff = 4.17 and early was computed to 3.1? 9:34
What is the maximum length of Zo (50ohm transmission line)? Only the width was calculated. Does this mean that the length is arbitrary? 22:00

robertferanec , 08-16-2022, 05:22 AM

- effective permittivity depends on track geometry, so for different line width you need to use different number: https://youtu.be/cOtv0ddR3aI?t=845
- longer the track is, more loss you will have, so weaker the signal will be.

Pixel , 08-16-2022, 11:23 AM

Thank you for your response. I already understand effective permability.

It means path width must be constant for 50ohm impedance for receiver and transmitter and the length as short as possible? And the width according to the calculations.
For example, the diagram below.

robertferanec , 08-18-2022, 08:49 AM

I am not an expert for antennas, maybe someone else can answer your questions?