Abstract: Methods, apparatuses, and other aspects are disclosed for microacoustic resonators. In one aspect, an apparatus includes a temperature compensation layer comprising a first surface and a second surface opposite the first surface, and a piezoelectric layer having a first surface and a second surface opposite the first surface, where the piezoelectric layer is disposed on the first surface of the temperature compensation layer with the second surface of the piezoelectric layer facing the first surface of the temperature compensation layer, and where the piezoelectric layer has an orientation configured to excite a longitudinal mode. The apparatus further includes an electrode structure comprising an interdigital transducer disposed on the first surface of the piezoelectric layer, where the second surface of the temperature compensation layer faces an air gap.

Abstract: An apparatus is disclosed for implementing a microacoustic filter with an acoustically-decoupled electrode structure. In an example aspect, the apparatus includes the microacoustic filter with a piezoelectric layer, a substrate, and an electrode structure. The piezoelectric layer has a crystalline structure operative to laterally excite a plate mode. The electrode structure is positioned between the piezoelectric layer and the substrate and has a has a first surface that faces the piezoelectric layer. The microacoustic filter also includes at least one spacer extending from the substrate past a plane defined by the first surface of the electrode structure and towards the piezoelectric layer to form a cavity between the electrode structure and the piezoelectric layer.

Abstract: Disclosed are polarization-inverted higher-order plate-mode resonators and methods for making the same. In an aspect, a plate-mode resonator includes a first piezoelectric layer having a first crystal orientation specified by a first set of Euler angles ?1, ?1, and ?1, a dielectric layer disposed on a top surface of the first piezoelectric layer, a second piezoelectric layer, disposed on a top surface of the dielectric layer, having a second crystal orientation specified by a second set of Euler angles ?2, ?2, and ?2, wherein az is approximately equal to ?1, wherein a difference between ?2 and ?1 is approximately 180 degrees, and wherein ?2 is approximately equal to ?1, and a metallization structure disposed on a top surface of the second piezoelectric layer, the metallization structure comprising at least one interdigital transducer.

Abstract: An apparatus is disclosed for partially suspending a piezoelectric layer using a dielectric. In an example aspect, the apparatus includes a microacoustic filter with a substrate layer, a piezoelectric layer, an electrode structure that is in contact with the piezoelectric layer, and a dielectric. The electrode structure includes multiple fingers arranged across a plane having a first axis that is perpendicular to the multiple fingers and a second axis that is parallel to the multiple fingers. The dielectric is configured to separate the piezoelectric layer from the substrate layer and define a cavity between the piezoelectric layer and the substrate layer. The dielectric is also configured to support the piezoelectric layer across at least three points along the first axis.

Abstract: A micromechanical sensor includes a substrate having a cavity; a flexible diaphragm spanning the cavity; and a lever element that spans the diaphragm and has a first and second end section on opposite sides of a center section. A first joint element is between the first end section and the substrate and a second joint element is between the center section and the diaphragm. The lever element can be pivoted due to a deflection of the diaphragm. Two capacitive sensors are provided, each having two electrodes, one electrode of each sensor being mounted at one of the end sections of the lever element, and the other being mounted on the substrate. The electrodes are disposed so that distances between the electrodes of different sensors are influenced oppositely when the lever element is pivoted. Also, an actuator is provided for applying an actuating force between the lever element and the substrate.

Abstract: A micromechanical sensor includes a substrate having a cavity; a flexible diaphragm that spans the cavity; and a lever element that spans the diaphragm and has a first and a second end section, the end sections lying on opposite sides of a center section. A first joint element is fitted between the first end section and the substrate and a second joint element is fitted between the center section and the diaphragm, so that the lever element is able to be pivoted due to a deflection of the diaphragm. In addition, two capacitive sensors are provided, each having two electrodes, one electrode of each sensor being mounted at one of the end sections of the lever element, and the other being mounted on the substrate. The electrodes of the sensors are disposed in such a way that distances between the electrodes of different sensors are influenced oppositely when the lever element is pivoted. Moreover, the sensor includes an actuator for applying an actuating force between the lever element and the substrate.