Antenna for GSM/Wifi


Hi guys, I'm planning on building an Android based ROV similar to OpenROV, and putting an android phone as the brain (with its camera and connectivity)

I was wondering, has anyone tried connecting an antenna cable from the ROV up above the water? wondering if I could pull of GSM this way, and use that as my communication channel.


For any decent length of cable you are going to need a pre-amp at the floating antenna, which will make the cable one-way. Somehow you need to get a signal out of the camera to tell the pre-amp if you are sending or receiving. I know RF but I don't know enough about Android phones to know how hard that will be.


Well, I'm not very good with RF so it was just an idea since I know from experience that holding a wire next to the phone tends to improve reception.

since the sub is a small hobby project, I would not need it to work for more then 2-3 meters.

will I still need a preamp?


For 2-3 meters it is worth a try without a per-amp. Get the lowest loss cable you can. Unless you have a better idea I would make a simple dipole antenna on the phone end and a 1/4 wave ground plane in the surface float. Both these types of antennas are very simple to construct. - example of 1/4 wave ground plane.


Wow, I really know nothing about electronics.

but I'll look at the links you sent me, maybe I'll learn something.