Broadband MEMS Microphone Arrays with Reduced Aperture Through 3D-Printed Waveguides

TL;DR

This paper introduces a cost-effective passive method using 3D-printed waveguides to reduce aperture size in ultrasound MEMS microphone arrays, enabling high-frequency beamforming without grating lobes.

Contribution

It presents a novel 3D-printed waveguide approach that allows smaller inter-element spacing in MEMS microphone arrays for ultrasound applications.

Findings

Enables higher frequency ultrasound beamforming with reduced array aperture.

Prevents grating lobes in ultrasound microphone arrays.

Demonstrates feasibility of 3D-printed waveguides for array miniaturization.

Abstract

In this paper we present a passive and cost-effective method for increasing the frequency range of ultrasound MEMS microphone arrays when using beamforming techniques. By applying a 3D-printed construction that reduces the acoustic aperture of the MEMS microphones we can create a regularly spaced microphone array layout with much smaller inter-element spacing than could be accomplished on a printed circuit board due to the physical size of the MEMS elements. This method allows the use of ultrasound sensors incorporating microphone arrays in combination with beamforming techniques without aliases due to grating lobes in applications such as sound source localization or the emulation of bat HRTFs.