AC/DC dual-mode magnetoelectric sensor with high magnetic field resolution and broad operating bandwidth

Abstract

In this study, a dual-mode Metglas/Pb(Zr,Ti)O3 magnetoelectric (ME) sensor was prepared for measuring weak magnetic fields. It is interesting to note that this ME sensor can work at alternating current (AC) and direct current (DC) dual-modes with high field resolution. In AC mode, a very accurate AC magnetic field resolution of 0.8 nT was achieved at a mechanical resonance frequency of 72.2 kHz; moreover, the operating frequency band for resolution better than 1 nT is as wide as 3.4 kHz. We proposed a DC bias field perturbation (DBFP) method to detect the DC magnetic field using lock-in amplifier technology. As a result, an ultra-accurate DC field resolution of 0.9 nT with noise power spectral density as low as 100 pT/Hz was obtained in the studied ME sensor via the DBFP method. The dual-mode ME sensor enables simultaneous measurement for DC and AC magnetic fields with wideband and accurate field resolution, which greatly enhances the measurement flexibility and application scope.

High-Resolution Magnetoelectric Sensor and Low-Frequency Measurement Using Frequency Up-Conversion Technique

“…Similarly, DC field resolution can be obtained using a DC bias field perturbation (DBFP) method considering the working points of = 60.101 kHz and = 0.5 Oe [ 8 ], as shown in Figure 5 . The red dotted line represents output voltage of the ME sensor operating at the above working points without the DC perturbation magnetic field ), which can be used as a reference voltage without input DC magnetic field.…”

“…Magnetic flux-type sensors exhibit very high magnetic field resolution, but the magnetic field resolution strongly depends on the dimension of the sensor. The reduction in dimensions results in a dramatic deterioration of magnetic field resolution [ 8 , 9 , 10 , 11 ]. Although the performance of the ME sensor also depends on its size, its size dependence is not as strong as that of the flux-type sensor, which is beneficial to its miniaturization [ 12 , 13 , 14 ].…”

Review of Magnetoelectric Sensors

“…In 2018 Turutin et al reported a new ME composite consisting of the y + 140 • cut congruent lithium niobate piezoelectric plates with an antiparallel polarized "head-to-head" bidomain structure and magnetostrictive material Metglas [48]. Based on this 2-2 ME bimorph, the equivalent magnetic noise spectral density was only 92 fT/Hz 1/2 and the directly measured resolution was found to be 200 fT at a bending resonance frequency of 6862 Hz (see Figure 6d), but one should note that the bandwidth of resonant ME sensors is normally below 1 kHz due to the high mechanical quality factor, which is a major limitation facing practical engineering applications [8,48,63]. It should however be noted that resonant ME sensors are greatly limited by the narrow bandwidth and specifically suited applications need to be considered.…”

Design and Optimization of Multi-Stage TMR Sensors for Power Equipment AC/DC Leakage Current Detection

“…Despite the Roche coil technology’s adequate bandwidth response, compact size, and low cost, it is primarily used for high current measurement and has limited capability for low frequency and low current measurement. In recent years, non-contact measurement technology has been rapidly developed in the context of smart grid sensing, where magnetic sensor technology is widely used for tiny current measurements due to its non-intrusive and electrically coupled isolation characteristics, allowing for high-accuracy measurements of currents below 100 μA [ 8 , 9 , 10 , 11 ]. Hall effect sensors are currently the most prevalent non-contact sensors on the market [ 12 , 13 , 14 ] due to their device simplicity, integrated processability, and low cost.…”