An apparatus is disclosed for proximity detection based on an electromagnetic field perturbation. In an example aspect, the apparatus includes an antenna array including at least two feed ports and a wireless transceiver coupled to the antenna array. The wireless transceiver is configured to generate an electromagnetic field via the antenna array. The wireless transceiver is also configured to receive energy from the electromagnetic field via the at least two feed ports. The wireless transceiver is additionally configured to adjust a transmission parameter based on the energy received via the at least two feed ports. The transmission parameter varies based on a range to an object that is present within the electromagnetic field.