Modeling and characterization of a silicon condenser microphone

Abstract

A single-chip silicon condenser microphone with a single deeply corrugated diaphragm (SDCD) has been developed. The fundamental characteristics, including mechanical sensitivity, resonance frequency, zero-pressure offset and temperature dependence of the diaphragm, are simulated using a finite element model (FEM). An analytical model is presented to validate that the higher mechanical sensitivity of the SDCD compared with the flat diaphragm with clamped edges is achieved by both releasing the residual stress and reducing the effective mechanical constant of the diaphragm structure. The electrostatic–structural coupling FEM analysis is used in combination with equivalent circuits to evaluate and understand the mechanical, electrostatic and acoustic performances of the microphone. The measurements show reasonable agreements with the theoretical predictions.

A MEMS Condenser Microphone-Based Intracochlear Acoustic Receiver

“…Acoustic, mechanical, and electrical elements ( Fig. 2a) of a MEMS CMIC, such as the diaphragm, back plate, back cavity, and electrical capacity were represented by acoustic impedances with equivalent mass, stiffness and/or damping properties [30]- [33]. The relevant dimensions of the individual microphone elements, including the microtube size, had to be much smaller than the wavelength of the acoustic wave for such representations [34].…”

Source microphone identification from speech recordings based on a Gaussian mixture model

“…The sensitivity of a condenser microphone depends on the electrical sensitivity of the microphone and the mechanical sensitivity of the microphone diaphragm. While the electrical sensitivity is the correlation of the thickness of the air gap between the 2 plates to the bias voltage, the mechanical sensitivity is related to the deflection of the diaphragm [17][18][19]. Moreover, electret condenser microphones have an integrated field-effect transistor preamplifier that acts as an impedance converter and amplifies the signal.…”

Design and fabrication of condenser microphone using wafer transfer and micro-electroplating technique

“…The air resistance of the air gap ( a R ) and the backplate hole ( h R ) can be expressed as [13] ) 8 …”