Antenna Length Limits?

I am using a photon inside of a metal enclosure, therefore I would like to extend the antenna out of the enclosure, but I’m concerned that the 100mm of the external antennas will not be long enough. Can I use [this] 2 u.fl extension without affecting the signal strength? I am currently planning on using the duck antenna.



@samsonthebrave, you may want to consider using a short U.FL to SMA cable coupled with an SMA external antenna. This will allow you to make a hole in your enclosure and securely mount the SMA connector through it. I am assuming your duck antenna has an SMA connector.


This is a helpful suggestion. Any thoughts on the maximum length the of the cable? I can probably make 10" work but prefer longer if I don’t have to worry about much signal decay.

Hi @samsonthebrave

Low-loss cables like the LMR-100A one that @peekay123 linked to above have loss ratings of around 30-40 dB per 100 feet at 2.4GHz so any length under say 3 ft would be less than 1 db of loss and probably acceptable. The connectors also have loss factors, so fewer connectors is better and I would avoid the “u.fl extension cable” if possible.

As always, if you are on the hairy edge of signal strength, you need to plan better.


great! super helpful.