B-field characterization and equivalent circuit modeling of a poly-SiGe-MEMS based Xylophone Bar Magnetometer

This paper reports a quantitative characterization of a poly-SiGe MEMS-based Xylophone Bar Magnetometer (XBM), thereby following a novel characterization method that is based on the measurement of the forward/backward transmission gains S21/S21 of the XBM treated as a two-port network. More specifically, this was done through monitoring the absolute amplitude of the resonant peaks of S21 and S12 with changing magnetic induction B. Also, we present for the first time a novel equivalent circuit for the two-port XBM, modeling effectively the electro-magneto-mechanical behavior of the magnetometer. The experimental measurements showed that poly-SiGe XBM is capable of being a linear magnetic sensor in mT range with a sensitivity 0.1dB=mT with an excitation power 5dBm fed to the electrodynamic/electrostatic port and a biasing voltage 14V applied through the sense/drive capacitor.