Trying to achieve 50Ohm Impedance

Upverter Support
#1

Hi All,

I am using this tool to calculate 50Ohm Impedance for a LoRa antenna.
Parameters I am inputting are :
(pretty basic ones for a 2 Layer, 1oz copper weight PCB from seeedstudio)

Trace Thickness T =1.4
Substrate Height = 62.9
Trace Width = 116 mil
Substrate Dielectric = 4.5

Impedance coming out is 50.1Ohms.
If above is correct I need to basically draw a trace 116 mil wide. With component pad size usually pretty small, are there any examples out there how to tackle such kind of trace ?

Obliged for the help.

Regards …

#2

It’s not uncommon to see traces change width near pins and pads. In particular when breaking out high-to-medium density BGAs, this is done all the time. I’m more of a digital guy myself and don’t no much about analog or RF, but I think going straight from a 20 Mil to a 116 Mil trace may cause some unwanted interference, so you could maybe use a copper pour to create a tapered region between the two trace sizes to mitigate that.

#3

Thanks Keith for the valuable feedback.
Cheers

#4

Thanks for sharing.