System for querying a passive sensor capable of being queried remotely in a metal recess with improved link budget and querying method

摘要

The subject of the invention is a system comprising: a reflective cavity (30) for the RF waves and comprising at least one acoustic wave sensor (21) having a resonance frequency band, coupled to a so-called sensor antenna (22) and; an interrogation / reception device of said sensor characterized in that said interrogation / reception device (10) comprises: o transmission / reception means of an RF signal (100) transmitting in an interrogation frequency band comprising said resonance frequency band of said sensor; at least a first transmitting / receiving antenna (111) and a second transmitting / receiving antenna (112), positioned in said cavity (30); means for dividing said signal into at least a first RF signal and a second RF signal (101), said first signal being transmitted to said first transmitting / receiving antenna and said second signal being transmitted to said second transmitting antenna / reception; means for creating a phase shift (102, 103) between said first RF signal and said second RF signal; o means for analyzing the power level of the received signal.;The invention also relates to an interrogation method used in said system.