A piezoelectric coaxial sensor includes: a sensor portion including a center conductor having a linear shape, a polymer piezoelectric layer containing polyvinylidene fluoride and that covers an outer peripheral surface of the center conductor, and a first outer conductor that surrounds an outer peripheral surface of the polymer piezoelectric layer; and jacket layers that each include a film having a tape shape wound to surround an outer peripheral surface of the sensor portion. The film of at least one of the jacket layers exposed to the outside of the piezoelectric coaxial sensor among the other jacket layers is adhered to a member in contact with an adhesive layer by the adhesive layer. The adhesive layer includes a thermoplastic resin having a melting point of 120° C. or lower.

A piezoelectric coaxial sensor includes: a sensor portion including a center conductor having a linear shape, a polymer piezoelectric layer containing polyvinylidene fluoride and that covers an outer peripheral surface of the center conductor, and a first outer conductor that surrounds an outer peripheral surface of the polymer piezoelectric layer; and jacket layers that each include a film having a tape shape wound to surround an outer peripheral surface of the sensor portion. The film of at least one of the jacket layers exposed to the outside of the piezoelectric coaxial sensor among the other jacket layers is adhered to a member in contact with an adhesive layer by the adhesive layer. The adhesive layer includes a thermoplastic resin having a melting point of 120° C. or lower.

An ultrasonic sensing device includes a housing, a piezoelectric assembly, a board and a plurality of fixing members. The housing includes a bottom wall, a top wall and a surrounding side wall connected between the top wall and the bottom wall. The piezoelectric assembly includes an encapsulating body and a piezoelectric sheet, wherein at least a portion of the piezoelectric sheet is enclosed by the encapsulating body and has a sensing surface exposed to the encapsulating body and facing the bottom wall. The board is disposed on the top wall of the housing and has a pressing surface facing the encapsulating body and the top wall. The plurality of fixing members is configured to fix the board to the top wall of the housing to press the board to the encapsulating body of the piezoelectric assembly, thereby pressing the sensing surface of the piezoelectric sheet to the bottom wall.

A method of manufacture and resulting structure for a single crystal electronic device with an enhanced strain interface region. The method of manufacture can include forming a nucleation layer overlying a substrate and forming a first and second single crystal layer overlying the nucleation layer. These first and second layers can be doped by introducing one or more impurity species to form the strained single crystal layers. The first and second strained layers can be aligned along the same crystallographic direction to form a strained single crystal bi-layer having an enhanced strain interface region. Using this enhanced single crystal bi-layer to form active or passive devices results in improved physical characteristics, such as enhanced photon velocity or improved density charges.

A substrate having a recessed portion, a diaphragm, and a piezoelectric actuator are provided, the diaphragm includes a first layer containing silicon as a constituent element, and a third layer disposed between the first layer and the piezoelectric actuator and containing zirconium as a constituent element, and a laminated side surface of the first layer and the third layer is covered with a moisture-resistant protective film containing at least one selected from the group made of oxide, nitride, metal, and diamond-like carbon.

An RF integrated circuit device can includes a substrate and a High Electron Mobility Transistor (HEMT) device on the substrate including a ScAlN layer configured to provide a buffer layer of the HEMT device to confine formation of a 2DEG channel region of the HEMT device. An RF piezoelectric resonator device can be on the substrate including the ScAlN layer sandwiched between a top electrode and a bottom electrode of the RF piezoelectric resonator device to provide a piezoelectric resonator for the RF piezoelectric resonator device.

An RF integrated circuit device can includes a substrate and a High Electron Mobility Transistor (HEMT) device on the substrate including a ScAlN layer configured to provide a buffer layer of the HEMT device to confine formation of a 2DEG channel region of the HEMT device. An RF piezoelectric resonator device can be on the substrate including the ScAlN layer sandwiched between a top electrode and a bottom electrode of the RF piezoelectric resonator device to provide a piezoelectric resonator for the RF piezoelectric resonator device.

A piezoelectric device includes a first substrate including a first surface on which piezoelectric elements and a common terminal coupled to the piezoelectric elements are placed, a second substrate including a second surface on which a common connecting terminal coupled to a control circuit is placed, a third substrate placed between the first substrate and the second substrate and including a third surface joined to the first surface and a fourth surface facing the second surface, and bonding portions bonding the second substrate and the third substrate by an adhesive, wherein the third substrate includes a first through hole penetrating from the third surface to the fourth surface and a first through electrode provided in the first through hole and coupled to the common terminal, the common connecting terminal is coupled to the first through electrode and electrically coupled to the common terminal via the first through electrode, and the second substrate includes a wall suppressing an outflow of the adhesive on the second surface facing the third substrate.

A system for a wireless communication infrastructure using single crystal devices. The wireless system can include a controller coupled to a power source, a signal processing module, and a plurality of transceiver modules. Each of the transceiver modules includes a transmit module configured on a transmit path and a receive module configured on a receive path. The transmit modules each include at least a transmit filter having one or more filter devices, while the receive modules each include at least a receive filter. Each of these filter devices includes a single crystal acoustic resonator device formed with a thin film transfer process with at least a first electrode material, a single crystal material, and a second electrode material. Wireless infrastructures using the present single crystal technology perform better in high power density applications, enable higher out of band rejection (OOBR), and achieve higher linearity as well.

A system for a wireless communication infrastructure using single crystal devices. The wireless system can include a controller coupled to a power source, a signal processing module, and a plurality of transceiver modules. Each of the transceiver modules includes a transmit module configured on a transmit path and a receive module configured on a receive path. The transmit modules each include at least a transmit filter having one or more filter devices, while the receive modules each include at least a receive filter. Each of these filter devices includes a single crystal acoustic resonator device formed with a thin film transfer process with at least a first electrode material, a single crystal material, and a second electrode material. Wireless infrastructures using the present single crystal technology perform better in high power density applications, enable higher out of band rejection (OOBR), and achieve higher linearity as well.