An acoustic wave device includes: a support substrate; a piezoelectric substrate bonded to the support substrate; a first acoustic wave element formed on the piezoelectric substrate; a frame formed on the support substrate to surround the first acoustic wave element; and a substrate formed on the frame so that a cavity to which the first acoustic wave element is exposed is formed above the piezoelectric substrate, wherein a difference in linear expansion coefficient between the support substrate and the substrate in a first direction in a surface direction of the piezoelectric substrate is less than a difference in linear expansion coefficient between the support substrate and the piezoelectric substrate in the first direction, and the piezoelectric substrate remains in a region where the first acoustic wave element is formed and is removed in a region where the frame is formed.

At least three acoustic filters circuits FC are arranged on a single chip CH. At least two of them are electrically connected already on the chip for multiplexing. This reduces space consumption and leads to smaller device size.

An apparatus includes a microelectromechanical system (MEMS) die having a first surface and an opposing second surface. The MEMS die includes a surface-mounted resonator on the first surface and includes a first inductor. The apparatus also includes first and second dies. The first die has a third surface and an opposing fourth surface. The first die is coupled to the MEMS die such that the third surface of the first die faces the first surface of the MEMS die. The first and second surfaces are spaced apart. The first die includes an oscillator circuit and a second inductor. The oscillator circuit is coupled to the second inductor. The second inductor is inductively coupled to the first inductor. The second die is electrically coupled to the first die.

An apparatus includes a microelectromechanical system (MEMS) die having a first surface and an opposing second surface. The MEMS die includes a surface-mounted resonator on the first surface and includes a first inductor. The apparatus also includes first and second dies. The first die has a third surface and an opposing fourth surface. The first die is coupled to the MEMS die such that the third surface of the first die faces the first surface of the MEMS die. The first and second surfaces are spaced apart. The first die includes an oscillator circuit and a second inductor. The oscillator circuit is coupled to the second inductor. The second inductor is inductively coupled to the first inductor. The second die is electrically coupled to the first die.

An acoustic wave resonator includes a substrate; a resonating part disposed on a first surface of the substrate and including a first electrode, a piezoelectric layer, and a second electrode; and a cap disposed on the first surface of the substrate and including an accommodating part accommodating the resonating part. The resonating part is configured to be operated by either one or both of a signal output from a first device substrate disposed facing a second surface of the substrate on an opposite side of the substrate from the first surface of the substrate and a signal output from a second device substrate disposed on the cap.

A front-end circuit component includes a base-body elastic wave filter and a mounted electronic component. The base-body elastic wave filter includes a piezoelectric substrate and an IDT electrode on an upper surface of a piezoelectric substrate. The mounted electronic component is mounted above the piezoelectric substrate to define a sealed space in which the IDT electrode is disposed.

A compound acoustic wave filter device comprises a support substrate having an including two or more circuit connection pads. An acoustic wave filter includes a piezoelectric filter element and two or more electrodes. The acoustic wave filter is micro-transfer printed onto the support substrate. An electrical conductor electrically connects one or more of the circuit connection pads to one or more of the electrodes.

A compound acoustic wave filter device comprises a support substrate having an including two or more circuit connection pads. An acoustic wave filter includes a piezoelectric filter element and two or more electrodes. The acoustic wave filter is micro-transfer printed onto the support substrate. An electrical conductor electrically connects one or more of the circuit connection pads to one or more of the electrodes.

A compound acoustic wave filter device comprises a support substrate having an including two or more circuit connection pads. An acoustic wave filter includes a piezoelectric filter element and two or more electrodes. The acoustic wave filter is micro-transfer printed onto the support substrate. An electrical conductor electrically connects one or more of the circuit connection pads to one or more of the electrodes.

At least three acoustic filters circuits FC are arranged on a single chip CH. At least two of them are electrically connected already on the chip for multiplexing. This reduces space consumption and leads to smaller device size.