Wide Bandwidth Lorentz-Force Magnetometer Based on Lateral Overtone Bulk Acoustic Resonator

This work presents a Lorentz-Force magnetometer based on a lateral overtone bulk acoustic resonator (LOBAR) for out-of-plane magnetic field detection (H-field). The magnetometer exploits H-field induced Lorentz-Force to excite an aluminum nitride (AlN) LOBAR and senses out H-field variation electrically via the piezoelectric transduction. Because of the high order mode, the magnetometer operates at a high resonance frequency under atmospheric pressure obtaining a very wide bandwidth of 250 kHz. The transmission characteristic Y12 of the magnetometer is presented, which shows a responsivity of 35.459 dB/T at a resonant frequency of 261.3 MHz.