Disclosed is a device (D′) for near-field radiofrequency communication with a portable element, the device including: at least one near-field communication primary antenna (A0) having a predetermined communication frequency (Fc); and a microcontroller (30′) electrically connected to the primary antenna, including a power supply source for the primary antenna and a receiver unit for the data (20′) received by the primary antenna. The communication device further includes: at least one passive relay antenna (A1 . . . A8), juxtaposed with the primary antenna, relay frequencies (F1 . . . F8), lying within a range of values around the predetermined communication frequency (Fc), but different from the predetermined communication frequency (Fc), electrically connected to the data receiver unit. Also included is a unit (C4) for adjusting the relay frequency. The communication device can be used to enlarge the near-field communication surface of the communication device.