Skyworks Global Pte. Ltd.

A surface acoustic wave resonator comprising a multilayer piezoelectric substrate including a layer of piezoelectric material, and interdigital transducer (IDT) electrodes disposed on the layer of piezoelectric material, the IDT electrodes including a first and second bus bars, a first plurality of electrode fingers extending from the first bus bar toward the second bus bar, and a second plurality of electrode fingers extending from the second bus bar toward the first bus bar and interleaved with the first plurality of electrode fingers in a central region of the resonator, gap regions defined between tips of the first plurality of electrode fingers and the second bus bar and between tips of the second plurality of electrode fingers and the first bus bar, regions of piezoelectric material forming the layer of piezoelectric material in the gap regions having a lesser permittivity and/or piezoelectricity than the piezoelectric material in the central regions.

Acoustic wave devices, including bulk and surface acoustic wave devices, include a temperature compensation layer in thermal communication with a piezoelectric layer. The temperature compensation layer includes a metal having a positive temperature coefficient of elasticity.

Aspects of this disclosure relate to a bulk acoustic wave that includes a piezoelectric having a lower magnitude effective piezoelectric coefficient in the engineered region than in a main acoustically active region. The bulk acoustic wave device includes a seed layer positioned between an electrode and the piezoelectric layer in the engineered region. A resonance associated with the engineered region can be at a lower frequency than a resonant frequency of the main acoustically active region. Related bulk acoustic wave dies, filters, multiplexers, radio frequency modules, radio frequency systems, wireless communication devices, and methods are disclosed.

Aspects of this disclosure relate to a bulk acoustic wave that includes a piezoelectric having a lower magnitude effective piezoelectric coefficient in the engineered region than in a main acoustically active region. The bulk acoustic wave device includes a raised frame layer in the engineered region. A resonance associated with the engineered region can be at a lower frequency than a resonant frequency of the main acoustically active region. Related bulk acoustic wave dies, filters, multiplexers, radio frequency modules, radio frequency systems, wireless communication devices, and methods are disclosed.

A system for compensating for thermal stress in piezoelectric microelectromechanical systems devices can have a piezoelectric layer at least partially spanning a cavity such that it generates electrical signals when external forces cause the piezoelectric layer to vibrate with respect to the cavity. At least one electrode layer can include a conductive metal positioned adjacent the piezoelectric layer and configured as an electrode to accept the electrical signals. The piezoelectric layer and electrode layer can have an expected thermal stress tending to cause expected deflection even when external forces are not causing the piezoelectric layer to vibrate. A compensation layer can be positioned adjacent at least one of the piezoelectric layer and the at least one electrode layer and configured to counteract the expected deflection from the expected thermal stress.

A filter module comprises a first terminal, a second terminal, and a filter disposed along each signal path extending from the first terminal to the second terminal, the filter including a plurality of series resonators and a plurality of shunt resonators disposed between the series resonators and a ground, at least one resonator among the plurality of series resonators and the plurality of shunt resonators being a first type of resonator with a temperature compensating layer for better temperature coefficient of frequency, at least one resonator among the plurality of series resonators and the plurality of shunt resonators being a second type of resonator without a temperature compensating layer.

A combination filter comprises a notch filter formed of acoustic wave resonators and a cavity filter electrically in series with the notch filter to provide for the combination filter to operate at higher powers and frequencies.

Aspects of this disclosure relate to bulk acoustic wave devices that have a raised frame structure. The raised frame structure can include a first raised frame layer that has a relatively low acoustic impedance. The raised frame structure can include a second raised frame layer that has a relatively high acoustic impedance. The first raised frame layer can have a thickness that is between about 0.02 and about 0.4 times the combined thickness H of the bulk acoustic wave device. The first raised frame layer can have a thickness that is between about 0.01 and about 0.2 times the resonant wavelength λ of the bulk acoustic wave device.

A bulk acoustic wave resonator comprises a piezoelectric material layer, a first metal layer disposed on the upper surface of the piezoelectric material layer, a second metal layer disposed on the lower surface of the piezoelectric material layer, and a laterally distributed raised frame including a first raised frame disposed on the upper surface of the first metal layer and having an inner raised frame section with a tapered portion and a non-tapered portion and an outer raised frame section, and a second raised frame disposed beneath the first metal layer and the outer raised frame section, but not beneath the inner raised frame section, the inner raised frame section being laterally disposed from a central active region of the bulk acoustic wave resonator by a first distance, the outer raised frame section being laterally disposed from the central active region by a second distance greater than the first distance.

A bulk acoustic wave resonator device comprises a piezoelectric material layer, a first metal layer having a lower surface disposed on the upper surface of the piezoelectric material layer, a second metal layer having an upper surface disposed on the lower surface of the piezoelectric material layer, and an oxide raised frame disposed between the lower surface of the first metal layer and the upper surface of the second metal layer and surrounding a central active region of the bulk acoustic wave resonator device, the central active region having a first side and a second side, the oxide raised frame having a width on the first side of the central active region that is different from the width of the oxide raised frame on the second side of the central active region to improve an operating parameter of the bulk acoustic wave resonator.