Design, fabrication and characterization of a resonant magnetic field sensor based on mechanically coupled dual-microresonator

• Design, fabrication and characterization of a novel resonant magnetic field sensor are presented.
• The proposed magnetic sensor consists of a dual-resonator with an induction coil laid on the resonant plate.
• The dual-resonator design not only increases the induced electromotive force, but also has a quality factor boosting effect for the resonator with lower Q in the array.
• The fabricated sensor is vacuum encapsulated in a ceramic chip carrier in order to reduce the Brownian noise floor for achieving a better performance.
• Experimental results show that the device offers a sensitivity of 35.92 μV/mT and 47.74 μV/mT, a scale factor nonlinearity of 0.65.

In this paper, design, fabrication and characterization of a resonant magnetic field sensor is presented. The proposed magnetic field sensor consists of a dual-resonator with an induction coil laid on the resonant plate. The dual-resonator array is mechanically coupled together through the λ/2 coupling beam. The dual-resonator design not only increases the induced electromotive force output through summing up the output from individual resonator, but also has a quality factor (Q) boosting effect for the resonator with lower Q in the array. The sensor exploits the principle of electromagnetic induction to detect external magnetic field through the electromotive force in the induction coil. The fabricated sensor is vacuum encapsulated in a ceramic chip carrier in order to reduce the Brownian noise floor for achieving a better performance. Experimental results show that the device offers a sensitivity of 35.92 μV/mT and 47.74 μV/mT, a scale factor nonlinearity of 0.65% and 1.19% with 30 V dc bias and 40 V dc bias, respectively.