A multi-port antenna structure for a wireless-enabled communications device includes a coupler-antenna having a first antenna port for transmitting electromagnetic signals and a second antenna port for receiving electromagnetic signals. The coupler-antenna is positioned on a chassis of the wireless enabled communications device to transmit energy between the chassis and the first and second antenna ports. Resonant modes of the chassis for one antenna port are orthogonal to resonant modes of the chassis for the other antenna port, such that the first and second antenna ports are isolated from each other.