Abstract: Various embodiments may relate to a resonator. The resonator may include a support including a substrate portion, and a membrane portion extending from the substrate portion over a cavity. The resonator may also include a piezoelectric layer on the membrane portion. The resonator may further include an electrode on the piezoelectric layer. The substrate portion may include dopants of a first conductivity type. The membrane portion may include dopants of a second conductivity type different from the first conductivity type. A ratio of a thickness of the membrane portion to a combined thickness of the electrode and the piezoelectric layer may be above 3:1 for temperature compensation.

Abstract: An air-pulse generating device includes a film structure including a flap pair. The film structure is actuated to perform a common mode movement, so as to form an amplitude-modulated ultrasonic air pressure variation with an ultrasonic carrier frequency. The film structure is actuated to perform a differential mode movement, so as to form an opening at a rate synchronous with the ultrasonic carrier frequency. The air-pulse generating device produces a plurality of air pulses according to the amplitude-modulated ultrasonic air pressure variation.

Abstract: Various embodiments may relate to a piezoelectric device. The piezoelectric device may include a substrate, and a layered stacked arrangement anchored to the substrate. The layered stacked arrangement may include a piezoelectric layer. The stacked arrangement may also include a first electrode on a first side of the piezoelectric layer. The stacked arrangement may further include a second electrode on a second side of the piezoelectric layer opposite the first side. The piezoelectric layer may include a first region including one or more dipole domains of a first type, and one or more dipole domains of a second type. The first electrode may be at least partially in contact with the first region and at least partially in contact with the second region.

Abstract: An air-pulse generating device includes a film structure including a flap pair. The film structure is actuated to perform a common mode movement, so as to form an amplitude-modulated ultrasonic air pressure variation with an ultrasonic carrier frequency. The film structure is actuated to perform a differential mode movement, so as to form an opening at a rate synchronous with the ultrasonic carrier frequency. The air-pulse generating device produces a plurality of air pulses according to the amplitude-modulated ultrasonic air pressure variation.

Abstract: An air-pulse generating device includes a film structure. The film structure is driven to form an amplitude-modulated ultrasonic air pressure variation with an ultrasonic carrier frequency. The film structure is driven to form an opening at a rate synchronous with the ultrasonic carrier frequency. The air-pulse generating device produces a plurality of air pulses according to the amplitude-modulated ultrasonic air pressure variation, and the plurality of air pulses is asymmetric.