Metglas/PZT-Magnetoelectric 2-D Geomagnetic Device for Computing Precise Angular Position

Abstract

A magnetoelectric 2-D geomagnetic device for the precisely angular position computation is provided. The magnetic sensor module consists of two Metglas/PZT magnetoelectric 1-D sensors in an orthogonal arrangement. The sensor signals are excited and detected by a self-made digital lock-in amplifier. For mapping output sensor signals, normalization was performed on the operational module. Both spatial (azimuth and pitch) angles are then easily computed while rotating and/or swinging the sensor module. This simple and low-cost geomagnetic device is integrated with mobile transceivers for automatic determination and control of the latter antenna direction with respect to the position of the geostationary satellite in communication.Index Terms-Digital signal processing, geomagnetism, magnetic field measurement, magnetoelectric effects.

Magnetoelectric Vortex Magnetic Field Sensors Based on the Metglas/PZT Laminates

“…This signal processing is performed using the commercial Lock-in amplifier. A current sensor device, however, can be completed thanks to the integration with a home-made digital lock-in amplifier architecture already reported before [39]. The progress will be presented elsewhere.…”

Low-frequency magnetic sensing by magnetoelectric metglas/bidomain LiNbO3long bars

“…Another way of dropping these frequencies is by using a large metglas-to-piezoelectric thickness ratio because of its comparatively larger density and compliance constants. Equations (5)(6)(7) show that in a simple unimorph with a large PE volume ratio, since 〈ℎ 31 〉 = ℎ 31 ���� � − 2 � ≈ 0, pure bending deformations will be very weak. In PE bimorphs, on the other hand, the resonance frequencies should be minimized and the amplitude of the resonant effects maximized for opposed polarization domains with equal thicknesses, since 〈ℎ 31 〉 has a local maximum at…”

“…where ∆ is the bandwidth of the input filter of the amplifier. Using equations (5)(6)(7)(8) and values of the material constants obtained from the literature, we can estimate the impedance, magnetoelectric coefficient, intrinsic voltage noise density and intrinsic magnetic noise density for some metglas / bidomain Y+128º-cut LNO free and side-fixed long bars with different lengths ( = 30, 40 and 45 mm). The bars also have a width of = 5 mm and thicknesses of = 29 μm for the metglas phase, and = 0.5 mm for the LNO phase with equally sized domains ( − = + = /2).…”

“…Recently there has been a large demand for sensitive magnetic sensors for biomedical applications, such as magnetoencephalography and magnetocardiology, which require the ability to detect very weak fields with amplitudes lower than 10 pT and frequencies below 100 Hz [1][2][3][4]. For this purpose, a new type of magnetoelectric (ME) sensors have been intensely investigated potentially offering a sensitive, low-cost and room-temperature operation, among others [1][2][3][4][5][6][7][8]. In particular, simple magnetoelectric 2-2 laminate composites containing mechanically coupled magnetostrictive (MS) and piezoelectric (PE) layers have been shown to be capable of producing large voltages in response to weak magnetic fields [9][10][11][12][13].…”

Review of Magnetoelectric Sensors

“…They also finished the circuit design and hardware implementation (Figure 10b). The obtained accuracy of angle measurement reached as low as ±0.5 • (Figure 10c) and the spatial angles can be automatically computed while rotating the sensor module [74].…”