Dual-Backplate Capacitive Aeroacoustic Microphone – Journal of the Acoustical Society of America Oct 2005

, ,

High‐performance instrumentation grade microphones are a crucial component for aeroacoustic measurements. This paper presents the design, fabrication, and characterization of a MEMS dual‐backplate capacitive microphone designed for aeroacoustic applications where small size, high dynamic range, and high bandwidth are key requirements. The microphone features a 230‐micron radius, 2‐micron air gaps, and a 118‐dB dynamic range. Experimental results indicate a sensitivity of 0.282 mV/Pa, a linear response up to 160 dB, a noise floor of 42 dB at 1 kHz in a 1‐Hz bin, and a measured resonant frequency of 230 kHz. A flat frequency response was measured up to 20 kHz in an 8.5×8.5−mm square rigid‐walled acoustic plane‐wave tube. The microphone was designed using an equivalent lumped‐element model, simulated using finite‐element methods, and fabricated using the SUMMiT V process at Sandia National Laboratories. Details on the acoustic and electrical characterization, fabrication process, and packaging will be described in the presentation.

Link to Publication

Skills

Posted on

October 1, 2005

Submit a Comment

Your email address will not be published.