Abstract:
A transducer array on a common substrate includes a membrane and first and second transducer devices. The membrane is formed on the common substrate, and includes a lower layer and an upper layer. The first transducer device includes a first resonator stack formed on at least the lower layer in a first portion of the membrane, the upper layer having a first thickness in the first portion of the membrane. The second transducer device includes a second resonator stack formed on at least the lower layer in a second portion of the membrane, the upper layer having a second thickness in the second portion of the membrane, where the second thickness is different from the first thickness, such that a first resonant frequency of the first transducer device is different from a second resonant frequency of the second transducer device.
Abstract:
A micromachined structure, comprises a substrate and a cavity in the substrate. The micromachined structure comprises a membrane layer disposed over the substrate and spanning the cavity.
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 device includes a first wafer, a second wafer, a gasket bonding the first wafer to the second wafer to define a cavity between the first wafer and the second wafer, and an acoustic transducer disposed on the first wafer and disposed within the cavity between the first wafer and the second wafer. One or more apertures are provided for communicating an acoustic signal between the acoustic transducer and an exterior of the device. An aperture may be formed in the cavity itself, or the cavity may be hermetically sealed. An aperture may be formed completely through the first wafer and located directly beneath at least a portion of the acoustic transducer.
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 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 film bulk acoustic resonator (FBAR) 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 disposed between the first electrode and the piezoelectric layer.
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:
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:
In a representative embodiment, a bulk acoustic wave (BAW) resonator, comprises: a cavity disposed in a substrate; a first electrode disposed over the cavity; a planarization layer disposed adjacent to the first electrode; a piezoelectric layer disposed over the first electrode; and a second electrode disposed over the piezoelectric layer.