Disclosed are a directional acoustic sensor, a method of adjusting directional characteristics using the directional acoustic sensor, and a method of attenuating an acoustic signal in a specific direction using the directional acoustic sensor. The directional acoustic sensor includes a plurality of resonance units arranged to have different directionalities and a signal processor configured to adjust directional characteristics by calculating at least one of a sum of and a difference between outputs of the resonance units. In this state, the signal processor attenuates an acoustic signal in a specific direction by using a plurality of directional characteristics obtained by calculating at least one of the sum of and the difference between the outputs of the resonance units at a certain ratio.

A compact directional acoustic sensor having an improved signal-to-noise ratio is disclosed. The disclosed directional acoustic sensor includes a first sensing device configured to generate different output gains based on different input directions of external energy, and configured to generate at least one first output signal having a first polarity based on external energy received from an input direction; a second sensing device configured to generate different output gains based on different input directions of external energy, and configured to generate at least one second output signal having a second polarity, that is different than the first polarity, based on the external energy received from the input direction; and at least one signal processor configured to generate at least one final output signal based on the at least one first output signal and the at least one second output signal.

A compact directional acoustic sensor having an improved signal-to-noise ratio is disclosed. The disclosed directional acoustic sensor includes a first sensing device configured to generate different output gains based on different input directions of external energy, and configured to generate at least one first output signal having a first polarity based on external energy received from an input direction; a second sensing device configured to generate different output gains based on different input directions of external energy, and configured to generate at least one second output signal having a second polarity, that is different than the first polarity, based on the external energy received from the input direction; and at least one signal processor configured to generate at least one final output signal based on the at least one first output signal and the at least one second output signal.

An acoustic wave device includes a substrate, functional elements on a first main surface of the substrate, an outer support portion on the substrate around a region where the functional elements are disposed, a cover portion opposed to the first main surface of the substrate with the outer support portion interposed therebetween, a support portion in a hollow space defined by the substrate, the outer support portion, and the cover portion, a wiring pattern electrically connected to the functional elements, and a through electrode extending through the substrate and electrically connected to the wiring pattern. A gap is provided between the support portion and the cover portion. A distance from the first main surface of the substrate to an upper surface of the support portion is greater than a distance from the first main surface of the substrate to an upper surface of the functional elements.

The present disclosure is of a bone conduction microphone. The bone conduction microphone comprises of a laminated structure and a base structure. The laminated structure is formed by a vibration unit and an acoustic transducer unit. The base structure is configured to load the laminated structure. At least one side of the laminated structure is physically connected to the base structure. The base structure vibrates based on an external vibration signal, the vibration unit deforms in response to the vibration of the base structure, and the acoustic transducer unit generates an electrical signal based on the deformation of the vibration unit. A resonant frequency of the bone conduction microphone is within a range of 2.5 kHz-4.5 kHz.

The present disclosure is of a bone conduction microphone. The bone conduction microphone comprises of a laminated structure and a base structure. The laminated structure is formed by a vibration unit and an acoustic transducer unit. The base structure is configured to load the laminated structure. At least one side of the laminated structure is physically connected to the base structure. The base structure vibrates based on an external vibration signal, the vibration unit deforms in response to the vibration of the base structure, and the acoustic transducer unit generates an electrical signal based on the deformation of the vibration unit. A resonant frequency of the bone conduction microphone is within a range of 2.5 kHz-4.5 kHz.

A method of deicing an airfoil is provided. In preferred embodiments, the method comprises coupling a plurality of piezo-electric transducers (PETs) to an inside surface of an airfoil. The PETs are electrically coupled to a DC-DC converter and a first inverter. The PETs are driven by sweeping the driving frequency of the plurality of PETs over a frequency range that spans at least 10 kHz and 100 kHz. In preferred embodiments, some PETs are driven at a phase shift to the other PETs.

A method of deicing an airfoil is provided. In preferred embodiments, the method comprises coupling a plurality of piezo-electric transducers (PETs) to an inside surface of an airfoil. The PETs are electrically coupled to a DC-DC converter and a first inverter. The PETs are driven by sweeping the driving frequency of the plurality of PETs over a frequency range that spans at least 10 kHz and 100 kHz. In preferred embodiments, some PETs are driven at a phase shift to the other PETs.

An apparatus includes a chamber and an intake device configured to control a flow of fluid into the chamber. The fluid comprises particles; a resonance device is configured to resonate the chamber to provide an acoustic standing wave within the chambers. The frequency of the standing wave is selected to cause particles above a specific size to collect at a node of the standing wave.

An apparatus includes a chamber and an intake device configured to control a flow of fluid into the chamber. The fluid comprises particles; a resonance device is configured to resonate the chamber to provide an acoustic standing wave within the chambers. The frequency of the standing wave is selected to cause particles above a specific size to collect at a node of the standing wave.