Author(s)

M. Pedersen, W. Olthuis & P. Bergveld

Abstract

A quasi static model for the electromechanical behaviour of condenser microphones is derived. Since the model is intended for use on microphones made with the silicon technology, special attention is paid to structures with backplates of comparable thickness with the membrane. It is shown that the deflection of the membrane and the backplate due to the applied DC potential across the microphone can be described by two non-linear coupled differential equations. A numerical method, based on finite differences, for the solution of this complex problem is suggested and applied. From the results it is shown how detailed information about the microphone performance and stability may be obtained. Introduction Capacitive microphones have, since the early dev

Keywords