Abstract: A composite case of an airborne ultrasonic transducer for transmitting, receiving, or both of ultrasound in atmospheric environment at an ultrasound pressure level is disclosed. The case comprises a first case component and at least a second case component. The second case component is made of a material different from the first case component having an acoustic impedance smaller than that of said first case component and is structurally connected to the first case component for reducing said mechanical quality factor while maintaining said ultrasound pressure level. The connection between the first and second case components is by strong bonding at an interface between the components so that the strong bonding forms a composite structure for the case.

Abstract: A composite case of an airborne ultrasonic transducer for transmitting, receiving, or both of ultrasound in atmospheric environment at an ultrasound pressure level is disclosed. The case comprises a first case component and at least a second case component. The second case component is made of a material different from the first case component having an acoustic impedance smaller than that of said first case component and is structurally connected to the first case component for reducing said mechanical quality factor while maintaining said ultrasound pressure level. The connection between the first and second case components is by strong bonding at an interface between the components so that the strong bonding forms a composite structure for the case.

Abstract: A composite case of an ultrasonic transducer for transmitting, receiving, or both of ultrasound is disclosed. The case comprises a first case component and at least a second case component. The second case component is made of a material different from the first case component and is structurally connected to the first case component by strong bonding at an interface between the components so that the strong bonding forms a composite structure for the case.

Abstract: An ultrasonic sensor device includes a sensing unit and a component module disposed in a casing. The sensing unit is configured to generate a sensing signal in response to receipt of an external sound wave. The component module includes a base seat, a circuit unit and a cushioning unit. The base seat has a base board and a lower seat portion under the base board. The base board is formed with a recess. The circuit unit is disposed in the recess, is coupled electrically to the sensing unit for receiving the sensing signal therefrom, and is to be coupled electrically to an external electronic circuit. The cushioning unit is disposed at the base seat, and is proximate to the sensing unit.