8 October 2026
SMA vs RP-SMA: how to tell them apart
A quick way to identify SMA and RP-SMA connectors before you order antennas or cables.
SMA and RP-SMA connectors look almost identical, and ordering the wrong one is one of the most common reasons an antenna “does not fit”. The difference is in the centre contact.
The quick test
Look into the connector:
| Connector | Thread | Centre contact |
|---|---|---|
| SMA male | Inside the nut | Pin |
| SMA female | On the outside | Socket (hole) |
| RP-SMA male | Inside the nut | Socket (hole) |
| RP-SMA female | On the outside | Pin |
“RP” stands for reverse polarity: the thread stays the same, but the pin and the socket swap places.
Where you usually find each
- SMA is common on FPV video transmitters, cellular modules and test equipment.
- RP-SMA is common on Wi-Fi routers, access points and some FPV goggles.
The two thread together but do not make contact, so a mismatched pair can look connected and still give no signal.
When in doubt
Send us a clear photo of the port on your device. We will confirm the connector and quote the antenna or cable with the right termination. Every Vectenna antenna and cable can be built with SMA, RP-SMA, IPEX, MCX or MMCX from 500 pcs. Get a quote.