Acoustic microphone array systems including arrays of microphones placed on a printed circuit board or other substrate in asymmetric patterns. A plurality of additional non-microphone components also reside on the board. The asymmetric placement of the microphones in the array provides flexibility in physically accommodating the additional non-microphone components.

Disclosed are an electrical-acoustic transformation device and an electronic device, including a moving coil electrical-acoustic transformation unit and a piezoelectric buzzer. The electrical-acoustic transformation device in the present invention has a moving coil sound generating structure and a piezoelectric sound generating structure. The piezoelectric plate compensates the high-frequency response of a vibrating system, realizing an electrical-acoustic transformation device with good performance and super wideband.

Some preferred embodiments include a microphone system for receiving sound waves, the microphone including a back plate, a radiation plate, first and second electrodes, first and second insulator layers, a power source and a microphone controller. The radiation plate is clamped to the back plate so that there is a hermetically sealed circular gap between the radiation plate and the back plate. The first electrode is fixedly attached to a side of the back plate proximate to the gap. The second electrode is fixedly attached to a side of the radiation plate. The insulator layers are attached to the back plate and/or the radiation plate, on respective gap sides thereof, so that the insulator layers are between the electrodes. The microphone controller is configured to use the power source to drive the microphone at a selected operating point comprising normalized static mechanical force, bias voltage, and relative bias voltage level. A radius and height of the gap, and a thickness of the radiation plate, are determined using the selected operating point so that a sensitivity of the microphone at the selected operating point is an optimum sensitivity for the selected operating point.

An impedance matching method for an electret microphone is provided. In some embodiments, the impedance matching method includes collecting a bias voltage between a source and a drain of a field effect transistor built in the electret microphone; determining whether the bias voltage is within a preset bias voltage threshold range; and if it is detected that the bias voltage is not within the preset bias voltage threshold range, sending a corresponding control signal to adjust load bias impedance so that the bias voltage is within the preset voltage threshold. An impedance matching apparatus for an electret microphone and a communication device are also provided.

An assembly including a transducer, such as a capacitive transducer, a vibration sensor or a microphone, and an amplifier for receiving and amplifying an output of the transducer, where the amplifier is supplied with a voltage being at least 60% of a voltage corresponding to an electrical field between two elements of the transducer. When the transducer is a biased transducer, the amplifier is supplied with a voltage being at least 60% of a biasing voltage of the transducer.

Disclosed is a structure for detecting the vibration displacement of a speaker, including: a vibration system having a movable pole plate; a magnetic circuit system; and a fixed pole plate provided under the vibration system and opposite to the movable pole plate, the movable pole plate and the fixed pole plate constituting a capacitor. Also disclosed is an acoustoelectric inter-conversion dual-effect device, further including an impedance transformer connected to the capacitor and including a field effect transistor and a diode. In the present invention, a movable pole plate of a capacitor is provided on a vibration system and a fixed pole plate is provided under the vibration system and fixed in position. When the vibration system vibrates, the change in capacitance is detected to calculate the actual displacement of the vibration system, which can reduce the power of the speaker device when the actual displacement of the vibration system exceeds a safety threshold. For an electronic device adopting such a speaker structure, the displacement of the vibration system of a speaker product can be detected in real time at the system end of the electronic device.

An acoustic energy detection circuit can include a microphone interface circuit configured for coupling to a microphone. The microphone interface circuit is configured to intermittently activate the microphone to detect acoustic energy and convert the acoustic energy to an electrical signal. The acoustic energy detection circuit also includes a comparator circuit for receiving the electrical signal and comparing the electrical signal with a threshold signal. The comparator circuit is configured to output an output signal to indicate detection of acoustic energy.

Systems, apparatuses, and methods for manufacturing a microelectromechanical system (MEMS) device. The MEMS device includes a substrate, a cap, a microelectromechanical component, and a tag. The substrate defines a port. The cap is coupled to the substrate. The substrate and the cap cooperatively define an interior cavity. The microelectromechanical component is disposed within the interior cavity and coupled to the substrate such that the microelectromechanical component is positioned over the port to at least partially isolate the port from the interior cavity. The tag is coupled to the substrate and the cap. The tag is positioned to secure the cap to the substrate.

The disclosure provides a MEMS device. The MEMS device comprises a printed circuit board, a cover attached to the printed circuit board to form a housing, at least one sound hole formed in the housing, a transducer with a diaphragm inside the housing, and at least one shutter structure. Each shutter structure is mounted to the housing around a respective sound hole. Each shutter structure comprises a moveable component disposed near the inner surface of the housing, the moveable component remains at an open position under regular pressure such that an air flow path from the sound hole to the at least one ventilation hole of the substrate across the moveable component is opened, and moves to a first closed position under a high external pressure to block the at least one ventilation hole and close the air flow path.

Improving noise rejection of a micro-electro-mechanical system (MEMS) microphone by utilizing a membrane sandwiched between oppositely biased backplates is presented herein. The MEMS microphone can comprise a diaphragm that converts an acoustic pressure into an electrical signal; a first backplate capacitively coupled to a first side of the diaphragmthe first backplate biased at a first direct current (DC) voltage; a second backplate capacitively coupled to a second side of the diaphragmthe second backplate biased at a second DC voltage; and an electronic amplifier that buffers the electrical signal to generate a buffered output signal representing the acoustic pressure.