A crystal oscillator and a method for fabricating the same is provided. In the method, a crystal package is provided. The crystal package includes a crystal blank and at least one laser-penetrating area. The laser-penetrating area is exposed outside. The crystal package is provided with at least one airtight space therein. At least one getter is formed in the airtight space. The location of the laser-penetrating area corresponds to that of the getter. A laser beam penetrates through the laser-penetrating area to activate the getter, thereby increasing the degree of vacuum of the airtight space.

There is provided a piezoelectric vibrator element which is excellent in vibration characteristics, high in quality, and capable of suppressing a frequency fluctuation after a frequency adjustment. The piezoelectric vibrator element is provided with a piezoelectric plate having a pair of vibrating arm parts, an electrode film disposed on obverse and reverse surfaces of the piezoelectric plate, and weight metal films for a frequency adjustment disposed on the electrode film at the obverse surface side in the vibrating arm parts. The reverse surface of the vibrating arm part has a reverse side exposure part from which the piezoelectric plate is exposed. The obverse surface of the vibrating arm part has an obverse side exposure part from which the weight metal film and the electrode film are removed, and from which the piezoelectric plate is exposed. A whole of the obverse side exposure part overlaps the reverse side exposure part at a distance from the electrode film on the reverse surface viewed from a thickness direction of the piezoelectric plate.

A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.

Bulk acoustic wave resonators of two or more different filters can be on a common die. The two filters can be included in a multiplexer, such as a duplexer, or implemented as standalone filters. With bulk acoustic wave resonators of two or more filters on the same die, the filters can be implemented in less physical space compared to implementing the same filters of different die. Related methods, radio frequency systems, radio frequency modules, and wireless communication devices are also disclosed.

A method for manufacturing a film bulk acoustic resonance device is disclosed. The proposed method, wherein the device has a specific resonant frequency, includes: providing an upper electrode; providing a lower electrode; configuring a first piezoelectric material layer between the upper electrode and the lower electrode; configuring a resonant frequency determining metal layer on the upper electrode, wherein the resonant frequency determining metal layer has a thickness; causing a resonant frequency of the film bulk acoustic resonance device and the thickness to form a curve; and when the thickness on the curve changes linearly, causing the resonant frequency to change non-linearly.

Techniques for improving acoustic wave device structures are disclosed, including filters and systems that may include such devices. An apparatus may comprise a first electrical filter including an acoustic wave device. The first electrical may having a first filter band in a Super High Frequency (SHF) band or an Extremely High Frequency (EHF) band to facilitate compliance with a regulatory requirement or a standards setting organization specification. For example, the first electrical filter may comprise a notch filter having a notch band overlapping at least a portion of an Earth Exploration Satellite Service (EESS) band to facilitate compliance with a regulatory requirement or the standards setting organization specification for the Earth Exploration Satellite Service (EESS) band.

A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.

Techniques for improving Bulk Acoustic Wave (BAW) resonator structures are disclosed, including fluidic systems, oscillators and systems that may include such devices. A bulk acoustic wave (BAW) resonator may comprise a substrate and a first layer of piezoelectric material. The bulk acoustic wave (BAW) resonator may comprise a top electrode. A sensing region may be acoustically coupled with the top electrode of the bulk acoustic wave (BAW) resonator.

Bulk acoustic wave resonators of two or more different filters can be on a common die. The two filters can be included in a multiplexer, such as a duplexer, or implemented as standalone filters. With bulk acoustic wave resonators of two or more filters on the same die, the filters can be implemented in less physical space compared to implementing the same filters of different die. Related methods, radio frequency systems, radio frequency modules, and wireless communication devices are also disclosed.

A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.