Changing wire antenna to RPSMA connector

Question

Hello!

I would like to replace the wire antenna in my XBees S3b 900HP with a connector, because I need my antenna to be in a different place than the XBee. Is that possible? A simple RPSMA connector would do?

Thanks so much, this is really important to my project.

Answer 1

Hello
I can only advise on Series 2 XBees, but I have done several modules where I've taken off the wire antenna and replaced with a UFL connector - it would be easier still to do an SMA type.
You already have the pads on the board for either connector.
If you choose to remove the wire antenna, you will most certainly null and void any warranty. If you have a dead XBee, practice on that.
Its a largish plated through hole so you need plenty of heat. Strip the insulation off the wire antenna, use a blob of solder on the iron for good contact and when you see the joint molten, very carefully pull out the antenna. If you are lucky it will come out leaving the PTH intact. Doing a UFL is tricky owing to the size but I bought a few Hirose SMD UFL. For very small SMDs, use an SMD tacky flux like Chip Qwik. For cable and bulkhead connector, Microchip certainly do the UFL (Digikey, Farnell etc.)
Before doing anything, it's worth running over the existing pads to see what connects to what. Don't even contemplate doing your own UFL connectors

Comments

Thanks for the answer and for the advice on removing the wire antenna. The problem I had was actually that the RPSMA connector's legs didn't match the pads on the Xbee. I don't know if there are different types of RPSMA connectors with different leg layouts.
When soldering the RPSMA connector the only pads I need to solder are the 3 pads on top of the Xbee, right? Nothing below?

Thanks again!

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The PCB on Series 2 at least is laid out for all the antenna options so some of pads will be shields and they all share the antenna trace. For the larger RPSMA connector, the three or four square pads are the shield and physically support the connector.
You need to go over the PCB with a meter to see what is connected to what. The wire antenna will connect to the "reception" trace - all I would worry about is when you remove the existing wire antenna, you might remove the plated through connection, in which case you would have to remake it with a via pin. The shield side should connect to the ground pin or the chip can.