Abstract: A MEMS microphone has an SOI wafer, a backplate formed in a portion of the SOI wafer, and a diaphragm adjacent to and movable relative to the backplate. The backplate has at least one trench that substantially circumscribes a central portion of the backplate.

Abstract: A MEMS microphone is capable of operating with less-than-one-volt bias voltage. An exemplary MEMS microphone can operate directly from a power rail (i.e., directly from VDD), i.e., without a DC-to-DC step-up voltage converter or other high bias voltage generator. The MEMS microphone has high mechanical and electrical sensitivity due, at least in part, to having high-compliance, i.e. low stiffness, springs and a relatively small gap between its diaphragm and its parallel conductive plate. In some embodiments, a diode-based voltage reference or a bandgap voltage reference supplies the bias voltage.

Abstract: A side-ported MEMS microphone package defines an acoustic path from a side of the package substrate to a microphone die disposed within a chamber defined by the substrate and a lid attached to the substrate. Optionally or alternatively, a circuit board, to which the microphone package is mounted, may define an acoustic path from an edge of the circuit board to a location under the microphone package, adjacent a bottom port on the microphone package. In either case, the acoustic path may be a hollow passage through at least a portion of the substrate or the circuit board. The passage may be defined by holes, channels, notches, etc. defined in each of several layers of a laminated substrate or circuit board, or the passage may be defined by holes drilled, molded or otherwise formed in a solid or laminated substrate or circuit board.

Abstract: A MEMS microphone has an SOI wafer, a backplate formed in a portion of the SOI wafer, and a diaphragm adjacent to and movable relative to the backplate. The backplate has at least one trench that substantially circumscribes a central portion of the backplate.

Abstract: A piano microphone apparatus configured to position at least one microphone within a sound cavity of a piano may comprise at least one piano interface configured to contact a case of a piano to suspend the microphone within the sound cavity of the piano. The piano microphone apparatus may also comprise at least one protruding member configured to receive a microphone and to adjustably position the microphone relative to at least one of the plurality of strings or soundboard. The length of the piano microphone apparatus may also be adjustable based on at least one dimension of the sound cavity.

Abstract: This invention relates to a system and method for reducing non-linear electrical distortion in an electroacoustic device. Specifically, the present invention relates to a system and method for reducing spatially dependent electrical distortion, for example, distortion caused by differences in electrical displacement between a conductive membrane and a counter electrode at different parts of the conductive membrane. The system and method for reducing non-linear electrical distortion has particular application in condenser microphones comprising, for example, a conductive diaphragm receptive to sound, and a backplate electrically coupled thereto to generate an electrical output. In one exemplary embodiment, the present invention provides an electroacoustic system comprising a conductive membrane and a counter electrode electrically coupled to the conductive membrane. A face of the counter electrode facing the conductive membrane is curved.

Abstract: A microphone housing system is disclosed having a tapered structure enclosed within the housing structure coupled to a rear portion of a microphone element. In the preferred embodiment, the tapered portion has a generally conic shape expanding away from the rear portion of the microphone element. The housing structure surrounding the tapered structure has a plurality of radially disposed opening or slots and fully or partially covered with a sound-resistive material. The housing system provides increased front-to-back signal ratio and increased overall gain and frequency response due to superior rear signal cancellation.