Dual-Mode Temperature And Magnetic Sensor Based On Fbar

Temperature and magnetic sensors based on MEMS technology benefit from their advantages such as small size, low power consumption and low cost, and are getting more and more attention. The dual-mode sensor based on thin film bulk acoustic resonator (FBAR) uses a Mo/AlN/FeGa sandwich structure as the resonant region, and has two resonant modes: $\mathrm{f}_{\mathrm{A}}$=2.3946 GHz and $\mathrm{f}_{\mathrm{B}}$=2.4628 GHz. The temperature sensitivities of frequency of modes A and B are 120 kHz/oC and 116 kHz/oC, the S11 intensity temperature sensitivities are 0.0014 dB$/^{\circ}$C and 0.0025 dB$/^{\circ}$C, respectively; the frequency magnetic field sensitivities are 2.72 kHz/Oe and 0.47 kHz/Oe, S11 intensity magnetic field sensitivities are 7E-5 dB/Oe and 6E-5 dB/Oe respectively. The dual-mode sensor has several sensing modes, in addition to detecting temperature and magnetic field independently, it can also correct the influence of temperature on magnetic sensing characteristics, which has important application value.