Reverse Polarity Connectors for WiFi Antennas

SMA Reverse polarity is one of the wireless antenna connector types which reverses the gender of the standard SMA connector type. For example RP-SMA female has the same external interface as a conventional female SMA connector, which consists of threads on the outer shell; however, the female receptacle is replaced by a male pin and vice versa.

The RP SMA connector, which is found on most home WiFi routers is connected to the antenna using an RP-SMA extension cable.  Cisco LinkSys Wireless Access Points have an Reverse Polarity TNC female connector, and so you can use an RP-TNC cable to connect a Cisco router with an upgraded antenna.

The reverse polarity concept constantly confuses both consumers and technical engineers, who ask why such a confusing convention was created in the first place and became so popular: The confusing nature was created by design, in order to thwart the end users who would add a high-gain antenna to their WIFI equipment, thus creating a device with power output that is non-compliant with FCC regulations related to preventing unauthorized connections with high gain antennas. The WiFi manufacturers of the early 2000s thought that reverse polarity connectors were so uncommon that the end-users would have a difficult time finding antennas with such connectors. Of course, by 2006, reverse polarity was so common that there were many antenna options to choose from.

Coaxial antenna cable assemblies are prepared by soldering the center wire inside the coaxial cable onto an RF connector, on the side of the cable that will attached to an antenna, that typically has an RP-SMA male connector.  The other end of the wire will be soldered either to a Printed Circuit Board (PCB), or to a U.FL connector that will attach to the mini-PCI card jack.