RADIO TRANSMISSION DEVICE HAVING A CENTRALIZED MANAGEMENT UNIT AND A PLURALITY OF REMOTE TRANSMISSION ANTENNAE

摘要

The invention concerns a low frequency radio transmission device for a passive entry system in a motor vehicle, comprising a centralized management unit (CU) and a specific number N of remote transmission antennae (EA1-EAn), where N is an integer greater than one. The management unit comprises a driving circuit (GEN) generating a driver signal (SC) of the antennae, which is delivered to a first terminal of each of the N antennae. The driver signal of the antennae is a sinusoidal or quasi-sinusoidal signal. The management unit further comprises switching means (DEMUX) comprising N switches (SW1-SWn) respectively associated with each of the antennae, which are arranged between a second antenna terminal and a reference potential. Each of the switches is controlled by the management unit to enable or disable the associated antenna.