Abstract: A device comprises a substrate, an acoustic stack, and a distributed Bragg reflector. The acoustic stack comprises a first electrode formed on the substrate, a first piezoelectric layer formed on the first electrode, a second electrode formed on the first piezoelectric layer, a second piezoelectric layer formed on the second electrode, and a third electrode formed on the second piezoelectric layer. The distributed Bragg reflector is formed adjacent to the acoustic stack and provides it with acoustic isolation.

Abstract: A bulk acoustic wave (BAW) structure includes a first electrode disposed over a substrate, a piezoelectric layer disposed over the first electrode, and a second electrode disposed over the first piezoelectric layer. A bridge is formed within the piezoelectric layer, where the bridge is surrounded by piezoelectric material of the piezoelectric layer.

Abstract: In accordance with a representative embodiment, a method, comprises: providing a substrate; forming a first piezoelectric layer having a compression-negative (CN) polarity over the substrate; and forming a second piezoelectric layer having a compression-positive (CP) over the substrate and adjacent to the first piezoelectric layer.

Abstract: In accordance with a representative embodiment, a bulk acoustic wave (BAW) resonator structure, comprises: a first BAW resonator comprising a first lower electrode, a first upper electrode and a first piezoelectric layer disposed between the first lower electrode and the first upper electrode; a second BAW resonator comprising a second lower electrode, a second upper electrode and a second piezoelectric layer disposed between the second lower electrode and the second upper electrode; and a single-material acoustic coupling layer disposed between the first and second BAW resonators, the acoustic coupling layer having an acoustic impedance less than approximately 6.0 MRayls and an acoustic attenuation less than approximately 1000 dB/cm.

Abstract: An apparatus including vertically separated acoustic resonators are disclosed. The apparatus includes a first acoustic resonator on a substrate and a second acoustic resonator vertically separated above the first acoustic resonator. Because the resonators are vertically separated above another, total area required to implement the resonators is reduced thereby savings in die size and cost are realized. The vertically separated resonators are supported by standoffs that are fabricated on the substrate, or on a resonator.

Abstract: An AC-DC power converter is composed of AC input, a first rectifying circuit, a second rectifying circuit, a DC-DC converter and a DC output. The DC-DC converter has a DC input. The first rectifying circuit and the second rectifying circuit are connected in parallel between the AC input and the DC input of the DC-DC converter. At least one of the rectifying circuits comprises a phase shifting element that provides a phase shift at the AC line frequency.

Abstract: An apparatus including vertically separated acoustic resonators are disclosed. The apparatus includes a first acoustic resonator on a substrate and a second acoustic resonator vertically separated above the first acoustic resonator. Because the resonators are vertically separated above another, total area required to implement the resonators is reduced thereby savings in die size and cost are realized. The vertically separated resonators are supported by standoffs that are fabricated on the substrate, or on a resonator.

Abstract: Method for fabricating an acoustical resonator on a substrate having a top surface. First, a depression in said top surface is generated. Next, the depression is filled with a sacrificial material. The filled depression has an upper surface level with said top surface of said substrate. Next, a first electrode is deposited on said upper surface. Then, a layer of piezoelectric material is deposited on said first electrode. A second electrode is deposited on the layer of piezoelectric material using a mass load lift-off process.

Abstract: A sensor senses an environmental condition. The sensor includes a film bulk acoustic resonator that includes a layer of material that causes resonant frequency and/or quality factor shifts of the film bulk acoustic resonator in response to changes in the environmental condition. The environmental condition may be relative humidity and the layer of material may be a moisture absorptive material.

Abstract: Embodiments of the acoustic galvanic isolator comprise a carrier signal source, a modulator connected to receive an information signal and the carrier signal, a demodulator, and an electrically-isolating acoustic coupler connected between the modulator and the demodulator. The electrically-isolating acoustic coupler comprises series-connected decoupled stacked bulk acoustic resonators (DSBARs).

Abstract: Embodiments of the acoustic galvanic isolator comprise a carrier signal source, a modulator connected to receive an information signal and the carrier signal, a demodulator, and an electrically-isolating acoustic coupler connected between the modulator and the demodulator. The acoustic coupler comprises no more than one decoupled stacked bulk acoustic resonator (DSBAR). An electrically-isolating acoustic coupler based on a single DSBAR is physically small and is inexpensive to fabricate yet is capable of passing information signals having data rates in excess of 100 Mbit/s and has a substantial breakdown voltage between its inputs and its outputs.

Abstract: A microfabricated device has a first substrate, a second substrate, a film bulk acoustic resonator (FBAR) device, and a circuit. The second substrate is bonded to the first substrate to define a chamber. The FBAR device is located on a surface of the first substrate and inside the chamber. The circuit is located on a surface of the second substrate and inside the chamber. An electrical connection connects the circuit and the FBAR device.

Abstract: A bulk acoustic wave device includes an acoustic decoupler between first and second film bulk acoustic resonators (FBARs). The first FBAR is resonant at a resonant frequency of the device and includes first and second planar electrodes abutting opposite sides of a first resonator volume free of any intervening electrodes and containing piezoelectric material disposed for acoustic vibrations parallel to a propagation axis normal to the first and second electrodes. The first FBAR has a first electrical impedance parallel to the propagation axis. The second FBAR is resonant at the resonant frequency and includes third and fourth planar electrodes abutting opposite sides of a second resonator volume free of any intervening electrodes and containing piezoelectric material disposed for acoustic vibrations parallel to the propagation axis. The second FBAR has a second electrical impedance parallel to the propagation axis and different from the first electrical impedance.

Abstract: An acoustic power transformer includes: an input port adapted to receive an input signal; a transmitting acoustic transducer coupled to the input port and adapted to transmit an acoustic wave in response to the input signal received at the input port; a receiving acoustic transducer adapted to receive the acoustic wave and in response thereto to produce an output signal; an output port adapted to output the output signal; and an acoustic medium disposed in an acoustic wave propagation path between the transmitting acoustic transducer and the receiving acoustic transducer. In one case, at least one of the transmitting acoustic transducer and receiving acoustic transducer includes a Fresnel lens. In another case, the transformer includes an acoustic lens disposed in the acoustic wave propagation path between the transmitting acoustic transducer and the receiving acoustic transducer.

Abstract: A substrate defining a cavity comprising a wide, shallow first portion and a narrow, deep second portion is provided. The first portion of the cavity extends into the substrate from the front side of the substrate and is filled with sacrificial material. The second portion extends deeper into the substrate from the first portion. A device structure is fabricated over the sacrificial material. A release etchant is introduced from the back side of the substrate via the second portion of the cavity to remove from the first portion of the cavity the sacrificial material underlying the device structure. Removing from the first portion of the cavity the sacrificial material underlying the device structure by introducing the release etchant from the back side of the substrate via the second portion of the cavity allows the release etch to be performed without exposing the device structure to the release etchant.

Abstract: An apparatus including vertically separated acoustic resonators are disclosed. The apparatus includes a first acoustic resonator on a substrate and a second acoustic resonator vertically separated above the first acoustic resonator. Because the resonators are vertically separated above another, total area required to implement the resonators is reduced thereby savings in die size and cost are realized. The vertically separated resonators are supported by standoffs that are fabricated on the substrate, or on a resonator.

Abstract: The temperature-compensated film bulk acoustic resonator (FBAR) device comprises an FBAR stack that comprises an FBAR characterized by a resonant frequency having a temperature coefficient and a temperature-compensating layer comprising doped silicon dioxide. The FBAR comprises opposed planar electrodes and a piezoelectric element between the electrodes. The piezoelectric element has a temperature coefficient on which the temperature coefficient of the resonant frequency of the FBAR depends at least in part.

Abstract: Method for fabricating an acoustical resonator on a substrate having a top surface. First, a depression in said top surface is generated. Next, the depression is filled with a sacrificial material. The filled depression has an upper surface level with said top surface of said substrate. Next, a first electrode is deposited on said upper surface. Then, a layer of piezoelectric material is deposited on said first electrode. A second electrode is deposited on the layer of piezoelectric material using a mass load lift-off process.

Abstract: In one aspect, a data communication system includes a modulator, an integrated acoustic data coupler, and a demodulator. The modulator modulates a carrier signal having a frequency in an operating frequency range in response to an input data signal and provides the modulated carrier signal at a modulator output. The integrated acoustic data coupler includes an acoustically resonant structure that has one or more acoustic resonant frequencies in the operating frequency range. The acoustically resonant structure includes a first thin film electro-acoustic transducer electrically coupled to the modulator output, a second thin film electro-acoustic transducer, and a substrate. The substrate supports, acoustically couples, and provides an electrical isolation barrier between the first and second thin film electro-acoustic transducers.

Abstract: An AC-DC power converter is composed of AC input, a first rectifying circuit, a second rectifying circuit, a DC-DC converter and a DC output. The DC-DC converter has a DC input. The first rectifying circuit and the second rectifying circuit are connected in parallel between the AC input and the DC input of the DC-DC converter. At least one of the rectifying circuits comprises a phase shifting element that provides a phase shift at the AC line frequency.