A piezoelectric transformer that includes a piezoelectric body having driving portions and a power generating portion, an input electrode, and an output electrode. The driving portions and the power generating portion are arranged in the lengthwise direction of the piezoelectric body. The driving portions are disposed symmetrically relative to a plane that passes through a center of the piezoelectric body in the lengthwise direction and is orthogonal to the lengthwise direction, occupy no less than half of the regions in the piezoelectric body, and are include two or more adjacent polarized regions.

An elastic wave device in which a recess is provided on an upper side of a support, a piezoelectric thin film covers the recess, and an IDT electrode is provided on an upper surface of the piezoelectric thin film. A plate wave of an S0 mode or SH0 mode is used. A plurality of grooves are provided in the upper surface or lower surface of the piezoelectric thin film at a portion of the piezoelectric thin film that is positioned on a hollow section.

A piezoelectric multi-layer component includes a piezoelectric main body, which has an inlet area and an outlet area. In the outlet area or in the inlet area at least two adjacent layers are polarized antiparallel to each other and at least two adjacent layers are polarized parallel to each other.

A surface-guided bulk wave transducer includes a stack of an acoustic substrate, an electric ground plane, and a network of synchronous acoustic excitation sources with two combs of elementary piezoelectric transducers alternately interlaced two-by-two according to a periodic network step corresponding to a propagation mode of a surface-guided bulk wave of the acoustic substrate. Each elementary piezoelectric transducer includes a single and different rod with a parallelepipedal shape for which the nature, the cut of the piezoelectric material, the height h, and the width are selected for increasing the electromechanical coupling coefficient of the transducer assembly to a high level.

Provided is a surface acoustic wave device using a novel and steadily suppliable piezoelectric material that is resistant to a high-temperature environment and enables the surface acoustic wave device to use a 2 GHz to 2.5 GHz band or higher. The surface acoustic wave device includes: a piezoelectric substrate formed from a monocrystal of gehlenite (CAS: Ca2Al(AlSi)O7); and interdigital transducers formed on a surface acoustic wave propagation plane of the piezoelectric substrate.

A resonator element for use in a filter is provided. The resonator element includes a first resonator acoustically coupled to a second resonator. The first resonator has terminals for incorporation in a filter structure. A tuning circuit is coupled to the second resonator to enable tuning of the resonator element.

A surface acoustic wave (SAW) device includes: a base substrate; a piezo-electric material layer; at least one interdigitated electrode pair disposed on the piezo-electric material layer; and an acoustic wave suppression layer disposed between the piezo-electric material layer and the base substrate, the acoustic wave suppression layer being configured to suppress an acoustic wave propagating in a direction from the piezo-electric material layer to the base substrate.

A surface acoustic wave filter includes first and second signal terminals and first and second IDT electrodes that are adjacent to or in a vicinity of each other in an x-axis direction and that each includes a pair of comb-shaped electrodes each including a busbar electrode extending in the x-axis direction and electrode fingers extending in a y-axis direction. One of the comb-shaped electrodes in each of the first and second IDT electrodes is electrically connected to the first and second signal terminals, respectively. The surface acoustic wave filter further includes a bridging capacitance including a pair of comb-shaped electrodes arranged in a region outside an overlap region of the electrode fingers. One of the comb-shaped electrodes of the bridging capacitance is electrically connected to the comb-shaped electrode in the first IDT electrode. The other of the comb-shaped electrodes of the bridging capacitance is electrically connected to the comb-shaped electrode in the second IDT electrode.

An ultrasonic sensor includes a substrate. A first electrode and a first piezoelectric layer are stacked on one side of the substrate. A second electrode and a second piezoelectric layer are stacked on the other side of the substrate. A notch is defined in the first piezoelectric layer. And a conductive film is coated within the notch to couple the first electrode and the first piezoelectric layer.

An apparatus for producing a plasma including a control circuit which is electrically connected to a piezoelectric transformer in order to excite the piezoelectric transformer. A hand-held device that uses the apparatus. The piezoelectric transformer is constructed of several layers. The control circuit is implemented on a circuit board, and the piezoelectric transformer is held over the circuit board by means of a region of a first end. A high voltage is applied to a second free end of the piezoelectric transformer. The plasma is produced at atmospheric pressure.