TEMPERATURE SENSOR COMPRISING A HIGH-OVERTONE BULK ACOUSTIC RESONATOR

This temperature sensor includes an HBAR resonator, a unit for determining the difference between two distinct resonance frequencies at a temperature T, measured between two electrodes of a same pair of the HBAR resonator and a unit for determining the temperature of the resonator from the difference in frequencies and from a one-to-one function providing the match between the temperature and the frequency difference. The resonator is formed by a stack of a first electrode, a transducer, a second electrode, and acoustic substrate and the cuts of the transducer and of the substrate are selected so as to obtain high electro-acoustic couplings and a difference in frequency temperature sensitivities between two distinct vibration modes co-existing within the resonator, greater than or equal to 1 ppm·K−1.