The invention relates to a passive transmitter-receiver device (6,28,33) fed by an electromagnetic wave, provided with an antenna comprising a loop (7, 30, 34) which is associated with an electronic transponder chip (9), said loop being able to feed the electronic chip by an induced current which is generated when it is cross-flown by an electromagnetic wave (H1, H2, H3, Ha, Hr) carrying information, and to transmit a second electromagnetic wave carrying a response from the electronic chip. The antenna is configured in such a way that the loop includes at least two non-coplanar or non-parallel parts in a position of use.