Abstract: An acoustic resonator comprises a first electrode a second electrode and a piezoelectric layer disposed between the first and second electrodes. The acoustic resonator further comprises a reflective element disposed beneath the first electrode, the second electrode and the piezoelectric layer. An overlap of the reflective element, the first electrode, the second electrode and the piezoelectric layer comprises an active area of the acoustic resonator. The acoustic resonator also comprises a bridge adjacent to a termination of the active area of the acoustic resonator.

Abstract: A method of forming a device having an airbridge on a substrate includes forming a plated conductive layer of the airbridge over at least a photoresist layer on a portion of the substrate, the plated conductive layer defining a corresponding opening for exposing a portion of the photoresist layer. The method further includes undercutting the photoresist layer to form a gap in the photoresist layer beneath the plated conductive layer at the opening, and forming an adhesion layer on the plated conductive layer and the exposed portion of the photoresist layer, the adhesion layer having a break at the gap beneath the plated conductive layer. The photoresist layer and a portion of the adhesion layer formed on the exposed portion of the photoresist layer is removed, which includes etching the photoresist layer through the break in the adhesion layer. An insulating layer is formed on at least the adhesion layer, enhancing adhesion of the insulating layer to the plated conductive layer.

Abstract: In accordance with another representative embodiment, a high-frequency signal transmitter a power amplifier configured to supply a high-frequency signal; an antenna configured to transmit the high-frequency signal; a transmission line configured to transfer the high-frequency signal from the power amplifier to the antenna; and an impedance matching circuit connected to the transmission line. The high-frequency signal transmitter also comprises a mismatch detector.

Abstract: An acoustic device includes a transducer formed on a first surface of a substrate and an acoustic horn formed in the substrate by a dry-etching process through an opposing second surface of the substrate. The acoustic horn is positioned to amplify sound waves from the transducer and defines a non-linear cross-sectional profile.

Abstract: A method for fabricating an acoustic resonator comprises providing a substrate; fabricating a first electrode adjacent the substrate; fabricating a piezoelectric layer adjacent the first electrode; depositing electrode material to form a second electrode up to a first thickness adjacent the piezoelectric layer; depositing a first photo mask over the second electrode; depositing additional electrode material to form the second electrode up to a second thickness; removing the photo mask thereby forming a recessed region in the second electrode; and filling the recessed region with a fill material.

Abstract: A device includes: a base substrate having a bonding pad and a peripheral pad, the peripheral pad encompassing the bonding pad; an acoustic resonator on the base substrate; a cap substrate having a bonding pad seal and a peripheral pad seal, the bonding pad seal bonding around the perimeter of the bonding pad and the peripheral pad seal bonding with the peripheral pad to define a hermetically sealed volume between the cap substrate and the base substrate, the cap substrate having a through hole therein over the bonding pad providing access for a connection to the bonding pad; a low-resistivity material layer region disposed on a portion of a surface of the cap substrate disposed inside the hermetically sealed volume, the material layer region being isolated from the bonding pad seal; and electronic circuitry disposed in the material layer region and electrical connected with the acoustic resonator.

Abstract: A device includes: a lead frame having an aperture in a central portion thereof; at least one acoustic transducer mounted on the lead frame above the aperture and configured to convert between acoustic energy and an electrical signal with low signal losses; a housing connected to the lead frame and including a base portion on a same side of the lead frame as the acoustic transducer; an amplifier is provided on a base portion of the housing in close proximity to the acoustic transducer; and a lid configured together with the base portion of the housing to define a cavity, wherein the acoustic transducer and the amplifier are closely positioned within the MEMS device cavity.

Abstract: A single-chip duplexer, interfacing a receiver and a transmitter with a common antenna, includes transmit and receive filters, an annular sealing ring and a conductive stripe. The transmit filter is connected between the antenna and the transmitter, and has a transmit passband. The receive filter is connected between the antenna and the receiver, and has a receive passband different from the transmit passband. The annular sealing ring is connected between a surface of the chip and a surface of a cap to form a sealed cavity between the chip and the cap. The conductive stripe extends across at least a portion of the surface of the chip between the transmit filter and the receive filter, the conductive stripe being directly connected to the sealing ring and electrically connected to ground. The conductive stripe provides at least one of magnetic shielding and capacitive shielding between the transmit filter and the receive filter.

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: A method for manufacturing a coupled resonator device includes forming a first BAW-device on a first substrate, forming a second BAW-device on a second substrate, and bonding the first and the second BAW-device such that the bonded first and second BAW-device are sandwiched between the first and second substrate.

Abstract: A method of fabricating a semiconductor device is disclosed. The method comprises patterning a photoresist over a compound semiconductor substrate; reducing a width of the photoresist; forming a hardmask over the substrate and not over the photoresist; removing the photoresist; etching to form and opening down to the substrate; forming a gate in the opening; and removing the hardmask except beneath the gate.

Abstract: A device for detecting helium in ambient atmosphere includes a resonator and a frequency detector. The resonator includes a piezoelectric film layer configured to absorb helium atoms. The frequency detector configured to detect a change in resonant frequency of the resonator when helium is absorbed into the piezoelectric film layer from the ambient atmosphere.

Abstract: A solid mount bulk acoustic wave resonator, comprises a first electrode; a second electrode; a piezoelectric layer disposed between the first and second electrodes; and an acoustic reflector comprising a plurality of layers and disposed beneath the first electrode, the second electrode and the piezoelectric layer, An overlap of the acoustic reflector, the first electrode, the second electrode and the piezoelectric layer defines an active area of the acoustic resonator, and the piezoelectric layer extends over an edge of the first electrode. The acoustic resonator also comprises a bridge adjacent to a termination of the active area of the acoustic resonator. The bridge overlaps a portion of the first electrode.

Abstract: An acoustic resonator device includes a composite first electrode on a substrate, a piezoelectric layer on the composite electrode, and a second electrode on the piezoelectric layer. The first electrode includes a buried temperature compensating layer having a positive temperature coefficient. The piezoelectric layer has a negative temperature coefficient, and thus the positive temperature coefficient of the temperature compensating layer offsets at least a portion of the negative temperature coefficient of the piezoelectric layer.

Abstract: An apparatus for providing impedance matching between a single-ended circuit and a differential circuit includes first and second capacitors and first and second inductors. The first capacitor is connected between an input/output of the single-ended circuit and a first differential input/output of the differential circuit. The first inductor is connected between the input/output of the single-ended circuit and a second differential input/output of the differential circuit. The second capacitor is connected between the second differential input/output of the differential circuit and ground. The second inductor is connected between the first differential input/output of the differential circuit and the second differential input/output of the differential circuit.

Abstract: A device, for transmitting or receiving ultrasonic signals, includes a transducer and an acoustic horn. The transducer is configured to convert between electrical energy and the ultrasonic signals, and may be a micro electromechanical system (MEMS) transducer. The acoustic horn is coupled to the transducer, and includes multiple apertures through which the ultrasonic signals are transmitted or received in order to manipulate at least one of a radiation pattern, frequency response or magnitude of the ultrasonic signals. The multiple apertures have different sizes.

Abstract: A device includes: a substrate having an aperture therethrough from a first side of the substrate to a second side of the substrate; a semiconductor die having an acoustic transducer, the semiconductor die being provided on the first side of the substrate such that the acoustic transducer is aligned with the aperture in the substrate; and a dual in-line package having a recess formed therein. The substrate is disposed such that the first side of the substrate faces the recess of the dual in-line package, and the semiconductor die is disposed between the first side of the substrate and the bottom surface of the recess in the dual in-line package.

Abstract: A duplexer includes first and second acoustic filters and a phase shifter. The first acoustic filter is connected between an antenna and the transmitter, and has a first passband. The second acoustic filter is connected between the antenna and the receiver, and has a second passband. The phase shifter includes at least one series capacitor connected in series with the antenna and at least one shunt inductor connected between the at least one capacitor and ground. The phase shifter is connected between the antenna and the first filter when the first passband is higher than the second passband, and provides a negative phase shift of an output impedance of the first filter. The phase shifter is connected between the antenna and the second filter when the second passband is higher than the first passband, and provides a negative phase shift of an input impedance of the second filter.

Abstract: An acoustic resonator comprises: a substrate; a first electrode adjacent the substrate; a layer of piezoelectric material adjacent the first electrode; a second electrode adjacent the layer of piezoelectric material; and a passivation layer adjacent the layer of piezoelectric material. The passivation layer includes a recessed feature. Fill material is provided in the recessed feature of the passivation layer.

Abstract: A method for manufacturing a piezoelectric resonator, comprising the step of: producing an arrangement comprising a piezoelectric layer having a resonance frequency temperature coefficient of a first sign, a first and a second electrode. The piezoelectric layer is arranged between the first and second electrodes, and a compensation layer is arranged between the first electrode and the piezoelectric layer. The compensation layer has a compensation material having a second resonance frequency temperature coefficient of a second sign opposite to the first one. The producing comprises providing the compensation material with a modification material to increase a conductivity of the compensation layer in a direction between the first electrode and the piezoelectric layer.