a detection and near - field communication device for detecting the approach of a portable device integrating a near - field communication antenna for communicating with the portable device , includes : a printed circuit including : an upper face oriented toward the portable device and a lower face , a microcontroller , a near - field reader , a detection module , a near - field communication antenna , situated on a face of the printed circuit having a first surface and being linked to the near - field reader ; a plurality of resonators made of copper wire windings , printed on a face of the printed circuit , covering a surface substantially identical to the first surface ; the resonators including frequency adjustment elements so as to resonate at the near - field communication frequency ; and the resonators generating a voltage variation across their terminals and being connected to the detection module to detect the approach of the portable device .