On the Design of a MEMS Microphone Array for a Mobile Beamforming Application
* Präsentierender Autor
Zusammenfassung:Considering the extensive use of smartphones and their outstanding camera capabilities these days, it’s desirable to record a high-quality audio signal in tandem with capturing video, e.g. at a rock concert. For a rather immersive sound experience when playing back smartphone-recorded material it’s mandatory to preserve the acoustic environment’s spatial properties. On that note, a design of a miniature microphone array to be rear-mounted on a smartphone is proposed. In the course of this work, we’ll focus on the development of a proper microphone arrangement that meets application-specific requirements. Therefore, several geometries are evaluated in terms of directivity index, half-power beam width and side lobe attenuation using a simulation-driven approach. Once a suitable geometry has been found, the actual sensor placement is determined by thinning the array using a genetic algorithm. Then, a prototype of the design is implemented utilizing digital MEMS microphones. Finally, a spatial filter (beamformer) is applied to the raw sensor data in order to allow the capture of multi-channel audio and the suppression of interfering background noise.