In one embodiment, a method of manufacturing a semiconductor device includes oxidizing a substrate to form local oxide regions that extend above a top surface of the substrate. A membrane layer is formed over the local oxide regions and the top surface of the substrate. A portion of the substrate under the membrane layer is removed. The local oxide regions under the membrane layer are removed.

A MEMS microphone includes a substrate having a cavity, a diaphragm disposed above the substrate to correspond to the cavity, and a back plate disposed above the diaphragm. The diaphragm has a plurality of grooves for adjusting an elastic strength of the diaphragm.

A passive radiator unit and a speaker system using the passive radiator unit are provided. The passive radiator unit includes a first passive radiator comprising a first moving mass; a second passive radiator oriented opposite to the first passive radiator, the second passive radiator comprising a second moving mass; and a connecting structure connected between the first moving mass of the first passive radiator and the second moving mass of the second passive radiator. The connecting structure is configured to have a greater radial stiffness than an axial stiffness thereof to thereby prevent rocking movements while allowing normal vibrations of the first passive radiator and the second passive radiator in an axial direction of the passive radiator unit.

A passive radiator unit and a speaker system using the passive radiator unit are provided. The passive radiator unit includes a first passive radiator comprising a first moving mass; a second passive radiator oriented opposite to the first passive radiator, the second passive radiator comprising a second moving mass; and a connecting structure connected between the first moving mass of the first passive radiator and the second moving mass of the second passive radiator. The connecting structure is configured to have a greater radial stiffness than an axial stiffness thereof to thereby prevent rocking movements while allowing normal vibrations of the first passive radiator and the second passive radiator in an axial direction of the passive radiator unit.

A MEMS microphone includes a substrate having a cavity, a diaphragm disposed above the substrate to correspond to the cavity, and a back plate disposed above the diaphragm. The diaphragm includes a concave-convex structure, and the back plate includes a second concave-convex structure corresponding to the concave-convex structure.

Disclosed in embodiments of the present disclosure are a diaphragm assembly, a loudspeaker module and an electronic device, the diaphragm assembly including a diaphragm body and an intermediate patch plate, wherein the diaphragm body includes a first diaphragm body and a second diaphragm body; the first diaphragm body is provided with a first hole; the intermediate patch plate includes a first intermediate patch plate; the second diaphragm body at least partially cover the first hole; the first intermediate patch plate is respectively connected to the first diaphragm body and the second diaphragm body; the first intermediate patch plate is configured to have an enclosed structure, or the intermediate patch plate includes a second intermediate patch plate connected to the second diaphragm body, such that the mid-high frequency curves of the loudspeaker module are smoother, thereby effectively improving the mid-high frequency tone quality.

Disclosed in embodiments of the present disclosure are a diaphragm assembly, a loudspeaker module and an electronic device, the diaphragm assembly including a diaphragm body and an intermediate patch plate, wherein the diaphragm body includes a first diaphragm body and a second diaphragm body; the first diaphragm body is provided with a first hole; the intermediate patch plate includes a first intermediate patch plate; the second diaphragm body at least partially cover the first hole; the first intermediate patch plate is respectively connected to the first diaphragm body and the second diaphragm body; the first intermediate patch plate is configured to have an enclosed structure, or the intermediate patch plate includes a second intermediate patch plate connected to the second diaphragm body, such that the mid-high frequency curves of the loudspeaker module are smoother, thereby effectively improving the mid-high frequency tone quality.

The invention provides apparatus and methods for interference based wave synthesis. The invention comprises (i) receiving information defining output wave characteristics, said output wave characteristics comprising at least an output wave frequency B, and an output signal amplitude M, (ii) determining a constant value A and (iii) driving a first input wave generator to generate a first input wave and (iv) driving a second input wave generator to generate a second input wave, such that the interfered wave synthesized by interference of the first input wave and the second input wave has output wave characteristics defined by the received information.

The invention provides apparatus and methods for interference based wave synthesis. The invention comprises (i) receiving information defining output wave characteristics, said output wave characteristics comprising at least an output wave frequency B, and an output signal amplitude M, (ii) determining a constant value A and (iii) driving a first input wave generator to generate a first input wave and (iv) driving a second input wave generator to generate a second input wave, such that the interfered wave synthesized by interference of the first input wave and the second input wave has output wave characteristics defined by the received information.

An acoustic transducer for generating electrical signals in response to acoustic signals, comprises a first diaphragm having a first corrugation formed therein. A second diaphragm has a second corrugation formed therein, and is spaced apart from the first diaphragm such that a cavity having a pressure lower than atmospheric pressure is formed therebetween. A back plate is disposed between the first diaphragm and the second diaphragm. One or more posts extend from at least one of the first diaphragm or the second diaphragm towards the other through the back plate. The one or more posts prevent each of the first diaphragm and the second diaphragm from contacting the back plate due to movement of the first diaphragm and/or the second diaphragm towards the back plate. Each of the first corrugation and the second corrugation protrude outwardly from the first diaphragm and the second diaphragm, respectively, away from the back plate.