A PMUT-Based Obstacle Sensing System with Enhanced Detection Capabilities via a System-Level Development Platform

This work presents a further development of a monolithic air-coupled PMUT array sensing system, operating at 200 kHz, for mid-air obstacle detection. Two significant advancements over state-of-the-art technologies are demonstrated: (1) A boundary-released PMUT structure with a coupled cantilever-plate design is proposed to enhance the sensitivity of the full transceiving loop, implemented in a linear array configuration; (2) enhanced resolution and accuracy achieved through pre-characterized acoustic field distribution and a double-stage delay-multiply-and-sum (DMAS) beamforming method. Additionally, a comprehensive development platform for acoustic MEMS devices is proposed, enabling a system-level optimization to fully exploit the performance of the entire sensing system.