Dual-Element MEMS Microphone for Mechanical Vibration Noise Cancellation

摘要

Disclosed are systems, devices, and methods for minimizing mechanical-vibration-induced noise in audio signals. In one aspect, a microphone is disclosed that includes a first backplate, a first diaphragm, a second backplate, and a second diaphragm. The first diaphragm moves relative to the first backplate in response to acoustic pressure waves in an environment and mechanical vibrations of the microphone, thereby causing a first capacitance change between the first diaphragm and the first backplate. The second diaphragm is substantially acoustically isolated from the acoustic pressure waves, and moves relative to the second backplate in response to the mechanical vibrations of the microphone, thereby causing a second capacitance change between the second diaphragm and the second backplate. The microphone further includes or is communicatively coupled to an integrated circuit configured to generate an acoustic signal based on the first capacitance and the second capacitance.

主权项

1. An apparatus comprising:
a microphone; and an integrated circuit, wherein the microphone comprises a first diaphragm arranged such that: (i) the first diaphragm moves, relative to a first backplate, in response to acoustic pressure waves in an environment of the microphone, and (ii) the first diaphragm also moves, relative to the first backplate, in response to mechanical vibrations of the microphone, wherein movement of the first diaphragm relative to the first backplate causes a first capacitance change between the first diaphragm and the first backplate; wherein the microphone further comprises a second diaphragm that is substantially acoustically isolated from the environment of the microphone such that the second diaphragm does not move substantially, relative to a second backplate, in response to the acoustic pressure waves in the environment, wherein the second diaphragm moves, relative to the second backplate, in response to the mechanical vibrations of the microphone, and wherein movement of the second diaphragm relative to the second backplate causes a second capacitance change between the second diaphragm and the second backplate; and wherein the integrated circuit is configured to generate an audio signal based on a difference between the first capacitance change and the second capacitance change.