Acoustic Parametric Effect MEMS Amplifier/Transducer for Sonar Applications

摘要

We have developed the first MEMS parametric amplifier for Sonar applications. The device used is a MEMS time-varying capacitor which is composed of an array of low-stress metalized silicon-nitride diaphragms, and is pumped by a large signal voltage at 1.64 MHz. This induces a large change in the capacitance, and results in parametric amplification of an input signal at 200 kHz. To our knowledge, this device is the first-ever MEMS mechanical up- converter parametric-effect amplifier developed with an up-conversion ratio of9:1. The measurements agree very well with theory, including the effect the series resistance and the Q of the MEMS time-varying capacitor.