Abstract: The technology of this application relates to a high electron mobility transistor, including a substrate and a GaN channel layer and an AlGaN barrier layer that are sequentially stacked on the substrate. Two through holes that are spaced apart from each other are opened in the AlGaN barrier layer. Each of the through holes penetrates the AlGaN barrier layer along a thickness direction of the AlGaN barrier layer, and a hole wall of each of the through holes has at least one stepped structure. Each of the through holes has an upper opening away from the substrate and a lower opening close to the substrate. The high electron mobility transistor further includes a source and a drain, where the source and the drain each fill up a through hole and are directly in contact with and connected to the GaN channel layer.

Abstract: This disclosure provides methods and apparatuses related to a microphone. In an implementation, a microphone includes a laser self-mixing apparatus and a diaphragm apparatus, the diaphragm apparatus includes a membrane configured to respond to a sound vibration, and the laser self-mixing apparatus and the diaphragm apparatus are separately configured to detect a vibration of the membrane. In an example method performed by the microphone, a first voltage signal is obtained by using the laser self-mixing apparatus, and a second voltage signal is simultaneously obtained by using the diaphragm apparatus. If the first voltage signal is less than or equal to a preset threshold, the first voltage signal is converted into an audio signal; or if the first voltage signal is greater than the preset threshold, the second voltage signal is converted into an audio signal.

Abstract: This disclosure provides methods and apparatuses related to a microphone. In an implementation, a microphone includes a laser self-mixing apparatus and a diaphragm apparatus, the diaphragm apparatus includes a membrane configured to respond to a sound vibration, and the laser self-mixing apparatus and the diaphragm apparatus are separately configured to detect a vibration of the membrane. In an example method performed by the microphone, a first voltage signal is obtained by using the laser self-mixing apparatus, and a second voltage signal is simultaneously obtained by using the diaphragm apparatus. If the first voltage signal is less than or equal to a preset threshold, the first voltage signal is converted into an audio signal; or if the first voltage signal is greater than the preset threshold, the second voltage signal is converted into an audio signal.

Abstract: The technology of this application relates to a high electron mobility transistor, including a substrate and a GaN channel layer and an AlGaN barrier layer that are sequentially stacked on the substrate. Two through holes that are spaced apart from each other are opened in the AlGaN barrier layer. Each of the through holes penetrates the AlGaN barrier layer along a thickness direction of the AlGaN barrier layer, and a hole wall of each of the through holes has at least one stepped structure. Each of the through holes has an upper opening away from the substrate and a lower opening close to the substrate. The high electron mobility transistor further includes a source and a drain, where the source and the drain each fill up a through hole and are directly in contact with and connected to the GaN channel layer.