Abstract: An improved electroacoustic component is provided. The component includes a carrier wafer with a passivation layer, a piezoelectric layer above the passivation layer and an interdigitated transducer in an electrode layer on the piezoelectric layer. The component is configured to work with a shear mode.

Abstract: 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.

Abstract: An improved electroacoustic component is provided. The component includes a carrier wafer with a passivation layer, a piezoelectric layer above the passivation layer and an interdigitated transducer in an electrode layer on the piezoelectric layer. The component is configured to work with a shear mode.

Abstract: This temperature sensor (2) includes an HBAR resonator (10), a unit (20) 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 (30) 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 (10) is formed by a stack of a first electrode (18), a transducer (12), a second electrode (19), and acoustic substrate (14) and the cuts of the transducer (12) and of the substrate (14) 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.

Abstract: The invention relates to a stress gauge of the type having an acoustic resonant structure, including a piezoelectric transducer (10) connected to a holder (20), the holder (20) including opposite the piezoelectric transducer (10) an imbedded reflecting portion (40). The imbedded reflecting portion (40) reflects the volume acoustic waves generated by the piezoelectric transducer (10) when it is excited according to a harmonic mode of the structure and propagating into said holder (20), the reflecting portion (40) being arranged at a distance from the piezoelectric transducer (10) such that the integral of the stress on the propagation distance of the volume acoustic waves up to their reflection is different from zero.

Abstract: The invention relates to a stress gauge of the type having an acoustic resonant structure, including a piezoelectric transducer (10) connected to a holder (20), the holder (20) including opposite the piezoelectric transducer (10) an imbedded reflecting portion (40). The imbedded reflecting portion (40) reflects the volume acoustic waves generated by the piezoelectric transducer (10) when it is excited according to a harmonic mode of the structure and propagating into said holder (20), the reflecting portion (40) being arranged at a distance from the piezoelectric transducer (10) such that the integral of the stress on the propagation distance of the volume acoustic waves up to their reflection is different from zero.

Abstract: A bulk wave acoustic resonant structure which is in accordance with the invention allows the difficulties encountered at high frequency, the impossibility of working at low frequency on simple structures and the absence of an adequate coupling level to be overcome. The invention therefore proposes the use of an additional layer of material which covers the upper electrode of a piezoelectric transducer in order to localize the position of maximum intensity of the dynamic stress close to the centre of the piezoelectric layer through the effect of propagation. The structure that is in accordance with the invention may be associated with Bragg mirrors and various uses are presented.