59results about How to "Excellent frequency temperature characteristics" patented technology

A piezoelectric thin film resonator has a substrate and a piezoelectric layered structure including a lower electrode, piezoelectric aluminum nitride thin film with c-axis orientation and upper electrode formed on the substrate in this order. The lower electrode are made of a metal thin film including a layer containing ruthenium as a major component having a full-width half maximum (FWHM) of a rocking curve of a (0002) diffraction peak of ruthenium of 3.0° or less. The piezoelectric aluminum nitride thin film formed on the lower electrode has a full-width half maximum (FWHM) of a rocking curve of a (0002) diffraction peak of 2.0° or less.

A surface acoustic wave device is provided. The surface acoustic wave device includes a piezoelectric substrate and an IDT which is disposed on the piezoelectric substrate and made of Al or an alloy containing Al as a main component and using an SH wave as an excitation wave, wherein the piezoelectric substrate is a rotated Y-cut quartz plate having a cut angle θ set to a range of −64.0°<θ<−49.3° rotated counterclockwise from a Z crystalline axis and a propagation direction of a surface acoustic wave set to a direction of 90°±5° with respect to an X crystalline axis, wherein, when a wavelength of an excited surface acoustic wave is denoted by λ, an electrode film thickness H/λ normalized with wavelength of the IDT is set to a range of 0.04<H/λ<0.12, and wherein, when a line occupancy rate mr of electrode fingers constituting the IDT is defined to be electrode finger width/(electrode finger width+electrode finger spacing), the line occupancy rate mr is set to a range of 0.53≦mr≦0.65.

In a method for manufacturing a quartz crystal unit, a quartz crystal tuning fork resonator is formed by etching a quartz crystal wafer to form a quartz crystal tuning fork base, quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, and a groove having stepped portions in at least one of opposite main surfaces of each of the quartz crystal tuning fork tines. A first electrode is disposed on at least one of the stepped portions of each of the grooves and a second electrode is disposed on each of side surfaces of each of the quartz crystal tuning fork tines. A frequency of oscillation of the quartz crystal tuning fork resonator is adjusted at least twice and in different steps. The quartz crystal tuning fork resonator is then mounted in a case and an open end of the case is covered with a lid.

A surface acoustic wave device including at least an interdigital transducer electrode that excites a Rayleigh surface acoustic wave on a surface of a crystal substrate and giving excitation in an upper limit mode of a stopband of the surface acoustic wave, wherein Euler angle representation (ψ, θ, Ψ) showing a cut angle and surface acoustic wave propagation direction of the crystal substrate is set as (0°, 0°≦θ≦180°, 0°<|Ψ|<90°).

A quartz crystal resonator includes a quartz crystal resonator element having a main surface including an X axis (electrical axis) and a Z' axis of an inclination rotated at an angle (y) equal to or greater than 36.4 degrees and equal to or smaller than, 40.5 degrees from a Z axis (optical axis) around the X axis, a main vibrating portion vibrating at a predetermined resonance frequency (f) and a supporting portion integrally formed with the main vibrating portion in such a manner as to be formed peripherally to surround the main vibrating portion, and two covers having a thermal expansion coefficient equal to or greater than 6x10^-6 per degrees centigrade and equal to or smaller than 10x10^-6 per degrees centigrade and bonded to the supporting portion so as to sandwich the quartz crystal resonator element therebetween.

A voltage-controlled oscillator includes a voltage-controlled phase-shift circuit, outputting a signal with the shift deviated from an input signal by a specified amount with an external control voltage Vt, a SAW resonator, a buffer, inputting a resonance signal having a specified resonance frequency from the SAW resonator, outputting a clock signal with a desired frequency, and outputting a positive-feedback-oscillation-loop output signal, wherein the voltage-controlled phase-shift circuit, the SAW resonator, and the buffer construct a positive-feedback oscillation loop, in which the frequency temperature characteristic of the SAW resonator is rotated by a specified amount using the temperature characteristic of the propagation delay time of the buffer to correct the frequency temperature characteristic of the SAW resonator.

A resonating element includes a resonator element that includes a vibrating portion and an excitation electrode provided on both main surfaces of the vibrating portion, an intermediate substrate in which the resonator element is mounted so as to be spaced from the excitation electrode, and a spiral electrode pattern that is provided on at least one main surface of the intermediate substrate, in which the electrode pattern is electrically connected to the excitation electrode.

A surface acoustic wave resonator includes a piezoelectric substrate and an interdigital transducer (IDT) that includes electrode fingers exciting a surface acoustic wave on the piezoelectric substrate, a first region at a center of the IDT, and a second region and a third region at opposite sides of the IDT. In the IDT, a line occupation rate at which an electromechanical coupling coefficient becomes a maximum is different from the line occupation rate at which reflection of the surface acoustic wave becomes a maximum.

A piezoelectric resonator suitable for use in a high frequency band is provided, in which variation in the piezoelectric material is reduced, variation in performance is reduced, and production can be performed without the need for a polarization treatment step. In the piezoelectric resonator, a piezoelectric material made of a wurtzite structure compound crystal is disposed, the crystal epitaxially grown in such a way that a (1,1,−2,0) crystal face becomes parallel to a surface of the R-plane sapphire substrate having a (0,1,−1,2) crystal face parallel to the substrate surface, and a pair of excitation electrodes are disposed on a pair of principal surfaces opposite to each other in the thickness direction of the piezoelectric material in such a way that the pair of excitation electrodes sandwich the C plane which is a (0,0,0,1) crystal face perpendicular to the (1,1,−2,0) crystal face of the tabular piezoelectric material.

The disclosed IDT/h-BN/c-BN/ diamond multilayer membrane structure SAW device comprises: from bottom to top, a nano-diamond membrane base prepared on mirror silicon, a nano c-BN membrane intermediate layer, a high-C-axis preferred orientated nano h-BN membrane, and an IDT. This invention can be used on condition of 2. 5GHz, high electromechanical coupling factor, smaller loss at 8w propagation, and low frequency temperature coefficient.

A piezoelectric resonating element includes a piezoelectric substrate having a rectangular vibrating portion and a thick-walled portion, excitation electrodes and, and lead electrodes. The thick-walled portion includes a fourth thick-walled portion, a third thick-walled portion, a first thick-walled portion, and a second thick-walled portion. The third thick-walled portion includes a third slope portion and a third thick-walled body, and at least one slit is formed in the third thick-walled portion.

The invention provides a high frequency surface acoustic wave device with an AlN (aluminum nitride) film as an interlayer. The device is characterized in that an a-axis preferred orientation AlN film is taken as a CVD (chemical vapor deposition) diamond substrate and a c-axis preferred orientation ZnO film is taken as an interlayer, the substrate and the interlayer are formed into an IDT(interdigital transducer)/ZnO/a-axis preferred orientation AlN/diamond multi-layered membrane structure and the structure is stacked with the IDT in sequence to form the high frequency surface acoustic wave device; the preparation method comprises the following steps of preparing an a-axis preferred oritention AlN film interlayer, and preparing a c-axis preferred oritentation ZnO film on the a-axis preferred orientation AlN film interlayer. The device and the preparation method provided by the invention have the following advantages that the sound velocity frequency dispersion caused by a large sound velocity gap between nanodiamond and ZnO can be solved, the application demand of the surface acoustic wave with high frequency above 4.8 GHz can be met, and moreover, the process is simple and easy to implement, and is beneficial for large-scale population and application.

The invention provides a cubic boron nitride piezoelectric film surface acoustic wave (SAW) device which is an IDT/c-BN/Al/ diamond multilayer film structure and is composed of a diamond substrate, an interface layer nano-aluminum film and a layer of nano-cubic boron nitride (c-BN) piezoelectric film formed on a surface of the nano-aluminum film. A preparation method of the device comprises the following steps: (1) employing a direct current magnetron sputtering method to deposit the nano-aluminum film on a nano-CVD diamond substrate surface; (2) employing a radio frequency magnetron sputtering method to deposit the nano-cubic boron nitride (c-BN) piezoelectric film on a surface of the nano-aluminum film; (3) preparing an interdigital transducer (IDT) on a surface of the nano-cubic boron nitride (c-BN) piezoelectric film. The surface acoustic wave device can satisfy application requirements of various fields like the surface acoustic wave (SAW) device with high frequency (4.8 GHz or more), a high electromechanical coupling coefficient, large power (more than 8 w), low propagation loss and a low frequency temperature coefficient, preparation technology is simple, application is easy, and popularization is facilitated.

A surface acoustic wave device has a piezoelectric substrate and an IDT formed on the piezoelectric substrate, and uses an excited wave as an SH wave. The piezoelectric substrate is a quartz plate in which a cut angle θ of a rotated Y-cut quartz substrate is set in the range of −65°≦θ≦−51° in a counter-clockwise direction from a crystal Z-axis and the propagation direction of a surface acoustic wave is set in the range (90°±5°) with respect to a crystal X-axis. The IDT is made of Ta or an alloyed metal containing Ta as the main component.