interfacing u.fl connectors

This is about how to use a transmitter / receiver component that uses a communication protocol, like this WiFly rn-xv, or this xbee pro, which doesn't come with a mounted antenna.  It does have a u.fl connector.

Here's how to interface this component with a proper antenna.

Step 1: What is a u.fl connector?

It is a mini coaxial cable connector designed for high radio frequencies up to 6GHz, which means that is has a wire conductor in the center, surrounded by an outer conductor, and an insulation between the two, called a dielectric layer.  Wifi, being 2.4 GHz transmission, often uses a u.fl connector as an adaptor wire for the antennas. 

You can see that the male connector is surface mounted on the pcb of the xbee and wifly rnxv. The female connector is on the end of the coaxial cable.