Parametrically amplified MEMS magnetometer

Abstract

This paper demonstrates how parametric amplification can improve the system wide signal to noise ratio (SNR) of MEMS resonant force sensors. Experiments demonstrate how parametric amplification increases the mechanical sensitivity of a Lorentz force based MEMS magnetometer. This increase in mechanical sensitivity amplifies both the Lorentz and Brownian forces. The RMS displacement caused by the 39 nT/radiclHz Brownian noise floor is amplified from 13.75 pm to 283 pm. In this study a maximum stable magnetic field sensitivity increase of 51 times was achieved which has an equivalent amplification to a linear resonator with a quality factor (Q) of 40,000.