Max allowed Antenna gain for LoRa


I am afraid, if it is the right forum to ask. I want to use antenna with better gain like more than 4 dBi for my loRa node and gateway. But according to rule in europe

Antenna gain

But i am seeing people are using antennas having gains more than 2.15 dBi. companies are selling them. Is it not the voilation?

Thank you.

If you dont reduce the TX power then yes it is a violation, however;

one caveat to that is that it is legitamate to limit the required power reduction to compensate for cable and connector losses.

If for instance you were using a 5.2dBi antenna, and you have say 2dBi of cable and connector losses, then you only need to reduce TX power by 1dBm.

Could you suggest me a best Antenna to get the max range?

What about this Antenna

Is it suitable with hardware (Arduino + LoRa shield) ? The one problem may occur, maybe this Antenna takes more power than the power that Arduino can provide.
Thank you

An antenna can never “take” more power than delivered into it.

The 2m cable delivered with the antenna you linked will give a loss of 0.875dB. 4dB (caused by the directivity of the antenna) - 0.875 = 3.125dB which is larger than the 2.5dBi allowed, if you use maximum allowed power of 14dBm.

The limit is 14dBm through an antenna that is assumed to be 2.15dBi, which is typical of a 1/4 wave vertical with radials or a dipole.

Having an antenna that has more range (max range as you put it) than the basic antenna is suggestive of an antenna that has gain. If the antenna has gain you need to back off the power, so your back to square one.

And yes I realise that there are mentions\discussions on the forum of ‘good range’ antennas, but you specifically asked about what was legal.

@mfalkvidd thank you :slight_smile:

Hi @asifsaeed999, please can I suggest that, to start with, you buy a commercial antenna from a major manufacturer that has good technical documentation.

A basic example for EU_863_870 MHz is :

Then take the time to understand the documentation and the performance of the antenna.
Then, with understanding, you can move on to alternatives.