LoRA antenna (update)
LoRA antenna (updated version of my first)
After some comments on the forum of TheThingsNetwork (link) I made a new antenna to check if the first one was luck that it worked. Some improvements could be made, so check out the info below.
I changed the overall length a bit and added a (closed) top loop to get a better SWR.
New lenghts are : 177 - 345*3/4 and 315*3/4mm.
So : Connector - 177 mm - first loop - 345*3/4 mm - second loop - 315*3/4 mm - top loop.
Close-up of the top loop.
SWR measurment result
The SWR plot of the new antenna (looks better then the previouse version).
Note : the small light line is the SWR line of the J-Pole antenna.