摘要:
A boundary acoustic waves device includes a piezoelectric substrate (16) having piezoelectricity, interdigitated electrodes (14a, 14b) formed on the piezoelectric substrate, a first medium (17) formed on the piezoelectric substrate so as to cover the interdigitated electrode, and a second medium (18) formed on the first medium. The interdigitated electrodes include a plurality of electrode fingers (13a, 13b) and bus bars (12a, 12b) that connect ends of the plurality of electrode fingers. A third medium (19a) is formed on the first medium. The second medium and the third medium are in contact with the first medium. The first medium, the second medium, and the third medium are formed of different materials. The first medium, the second medium, and the third medium are different in a ratio in length of a part with the third medium formed with respect to a length of a propagation path of boundary acoustic waves in a cross-section perpendicular to a longitudinal direction of the electrode fingers, in the longitudinal direction of the electrode fingers.
摘要:
A method of producing an acoustic wave device includes: forming an interdigital electrode 3 on a piezoelectric substrate 2; forming a barrier film 4 so as to cover the interdigital electrode 3; forming a medium 5 on the barrier film 4; measuring a frequency characteristic of an acoustic wave excited by the interdigital electrode 3; and forming, in an excitation region, an adjustment region having a thickness different from other portions by patterning the barrier film 4 or further providing an adjustment film. When forming the adjustment region, an area T of the adjusting area is adjusted in accordance with the measured frequency characteristic.
摘要:
An elastic wave device includes resonators having a piezoelectric substrate, a resonation unit formed on the piezoelectric substrate, and reflectors formed on respective sides of the resonation unit on the piezoelectric substrate, and bumps formed on the piezoelectric substrate. The resonators are configured such that two or more split resonators are connected in parallel, and a bump is formed in a region sandwiched between reflectors of the split resonators.
摘要:
An acoustic wave device includes a plurality of acoustic wave devices each including a substrate made of a piezoelectric material, a pair of interdigital electrodes formed on the substrate, each of the interdigital electrodes including a plurality of electrode fingers, and an adjustment medium. The adjustment medium includes at least a single layer and is formed on at least a part of the pair of the interdigital electrodes. The adjustment medium further includes at least one thick portion and a thin portion, the thin portion being null or thinner than the thick portion, a total area of the at least one thick portion in a region covering the pair of interdigital electrodes being determined according to a predetermined characteristic value, wherein the plurality of acoustic wave devices include at least two acoustic wave devices that differ from each other with respect to the size of the total area of the at least one thick portion of the adjustment medium.
摘要:
An acoustic wave element includes: resonators 2 each including an electrode to excite acoustic waves; a power supply wiring portion 3 that is disposed so as to connect the resonators 2 electrically; a piezoelectric substrate 4 on which the resonators 2 and the power supply wiring portion 3 are formed; a second medium 5 that is formed on the piezoelectric substrate 4 so as to cover the resonators 2; and a third medium 6 that is formed on the piezoelectric substrate 4 so as to cover at least the second medium 5 and the power supply wiring portion 3. A side surface 34 of the power supply wiring portion 3 that is in contact with a surface of the piezoelectric substrate 4 forms an obtuse first angle θ with respect to the surface 4a of the piezoelectric substrate 4.
摘要:
An elastic boundary wave device of the present invention includes a plurality of elastic boundary wave elements. The elastic boundary wave elements each include a piezoelectric material layer, an electrode disposed over the piezoelectric material layer, a first dielectric layer formed over the piezoelectric material layer so as to cover the electrode, and a second dielectric layer formed over the first dielectric layer. An acoustic velocity of the second dielectric layers is faster than an acoustic velocity of the first dielectric layers, and the acoustic velocity of the second dielectric layer of at least one elastic boundary wave element from among the plurality of elastic boundary wave elements is different from the acoustic velocity of the second dielectric layer of another of the elastic boundary wave elements. This enables improving the degree of suppression in use as a filter in the elastic boundary wave device.
摘要:
In an acoustic wave filter, a notch resonator is connected in series (or parallel) with a plurality of acoustic wave resonators connected in a ladder shape. The notch resonator has a main resonant frequency that is substantially equal to a sub-resonant frequency of the acoustic wave resonators. With this configuration, the occurrence of sub-resonant responses in filter characteristics can be suppressed, resulting in an improvement in communication characteristics.
摘要:
The surface acoustic wave device includes a piezoelectric substrate having formed on a surface thereof an interdigital transducer for exciting a surface acoustic wave, a cavity formed on a back surface of the piezoelectric substrate on a region corresponding to the region where the interdigital transducer is formed, and a low expansion material buried in the cavity.
摘要:
An optical device comprising an image formation unit consisting of a plurality of lens substrates each formed on the front and rear faces thereof with lens arrays and a display unit disposed on an object surface with respect to the image formation unit and displaying an image to be projected by the image formation unit, characterized in that the lens array is a cylindrical lens array and the generating line of a cylindrical array formed on the front face and the generating line of a cylindrical array formed on the rear face cross each other. The lens substrate formed on the front and rear faces thereof with cylindrical lens array is used to provide a small lightweight optical device of a full-size or magnified image system.
摘要:
It is an object to perform a thin and compact design of the objective lens driving device. In order to achieve the above object, optical beam is passed through a space surrounded by a tracking coil and a focusing coil which are adjacent to each other and fixed in a holder. Further, it is another object to position the objective lens with high precision in an objective lens driving device for switching a plurality of objective lenses in accordance with the type of an optical disc. In order to achieve this object, magnetic substances which are radially extended with the sliding shaft at the center are provided in the lens holder, and the magnetic substances are located within a plane perpendicular to the plane constituting the magnetic gap and at the outside of the magnetic gap. Still further, in an objective lens driving device it is another object to prevent the occurrence of positional displacement of the objective lens due to resistance force of current supply means such as FPC. To achieve this object, a first objective lens and a second objective lens are arranged so that the objective lens arrangement angle at which the first and second objective lenses are arranged with respect to the shaft center of the sliding shaft is displaced, by a predetermined amount, from the magnetic circuit arrangement angle at which the magnetic substances and the magnets are arranged with respect to the shaft center of the sliding shaft.