Sensing Mechanism of Surface Acoustic Wave Magnetic Field Sensors Based on Ferromagnetic Films

Yang, Yang; Mishra, Harshad; Han, Tao; Hage-Ali, Sami; Hehn, Michel; Elmazria, O.

doi:10.1109/tuffc.2021.3069382

Cited by 8 publications

(3 citation statements)

References 29 publications

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“…The operating principle of SAW delay line magnetic field sensors [ 6 ] is based on the magnetoelastic

E effect. It leads to changes of the Young’s modulus E and the related shear modulus G , respectively, of an additional magnetostrictive layer as a function of the material’s magnetization M , i.e., of an ambient magnetic flux density

(

and H denote the vacuum permeability and the magnetic field strength).…”

Section: Introductionmentioning

confidence: 99%

Phase Noise of SAW Delay Line Magnetic Field Sensors

Durdaut

Müller

Kittmann

et al. 2021

Sensors

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Surface acoustic wave (SAW) sensors for the detection of magnetic fields are currently being studied scientifically in many ways, especially since both their sensitivity as well as their detectivity could be significantly improved by the utilization of shear horizontal surface acoustic waves, i.e., Love waves, instead of Rayleigh waves. By now, low-frequency limits of detection (LOD) below 100 pT/Hz can be achieved. However, the LOD can only be further improved by gaining a deep understanding of the existing sensor-intrinsic noise sources and their impact on the sensor’s overall performance. This paper reports on a comprehensive study of the inherent noise of SAW delay line magnetic field sensors. In addition to the noise, however, the sensitivity is of importance, since both quantities are equally important for the LOD. Following the necessary explanations of the electrical and magnetic sensor properties, a further focus is on the losses within the sensor, since these are closely linked to the noise. The considered parameters are in particular the ambient magnetic bias field and the input power of the sensor. Depending on the sensor’s operating point, various noise mechanisms contribute to f0 white phase noise, f−1 flicker phase noise, and f−2 random walk of phase. Flicker phase noise due to magnetic hysteresis losses, i.e. random fluctuations of the magnetization, is usually dominant under typical operating conditions. Noise characteristics are related to the overall magnetic and magnetic domain behavior. Both calculations and measurements show that the LOD cannot be further improved by increasing the sensitivity. Instead, the losses occurring in the magnetic material need to be decreased.

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“…The operating principle of SAW delay line magnetic field sensors [ 6 ] is based on the magnetoelastic

(

and H denote the vacuum permeability and the magnetic field strength).…”

Section: Introductionmentioning

confidence: 99%

Phase Noise of SAW Delay Line Magnetic Field Sensors

Durdaut

Müller

Kittmann

et al. 2021

Sensors

View full text Add to dashboard Cite

show abstract

“…AlN piezoelectric materials, which enabled a measurement range of up to 300 pT in the presence of a DC-biased magnetic field [17]. Taking the magnetostriction effect, ΔE effect, and the third-order material constants into account, Yang et al investigated the sensing mechanism of SAW magnetic field sensors [18], and they also explored a grooved sensing surface structure to improve sensitivity. Obviously, the performance of an SAW-based current/magnetic sensor is significantly determined by the magnetostrictive coatings [19].…”

Section: Introductionmentioning

confidence: 99%

Enhanced Sensitivity of FeGa Thin-Film Coated SAW Current Sensor

et al. 2021

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A surface acoustic wave (SAW) device is proposed for sensing current by employing the patterned FeGa thin film as the sensitive interface. The layered media structure of FeGa/SiO2/LiNbO3 was established to reveal the working principle of the sensors, and an SAW chip patterned by delay-line and operating at 150 MHz was fabricated photolithographically on 128° YX LiNbO3 substrate. The FeGa thin film with a larger magnetostrictive coefficient was sputtered onto the acoustic propagation path of the SAW chip to build the sensing device. The prepared device was connected into the differential oscillation loop to construct the current sensor. The FeGa thin film produces magnetostrictive strain and so-called ΔE effect at the magnetic field generated by the applied current, which modulates the SAW propagation velocity accordingly. The differential frequency signal was collected to characterize the measurand. Larger sensitivity of 37.9 kHz/A, low hysteresis error of 0.81%, excellent repeatability and stability were achieved in the experiments from the developed sensing device.

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“…Based on theoretical finite element multi-physics coupling calculations, [30] synchronous single-port SAW resonators are fabricated to operate around the ISM band at 433 MHz and to exhibit a high sensitivity to magnetic field and almost zero TCF for Love wave mode. A one-port resonator can be connected to an antenna as a wireless and passive sensor, which is an advantage of a one-port resonator.…”

Section: Design and Fabricationmentioning

confidence: 99%

Wireless Multifunctional Surface Acoustic Wave Sensor for Magnetic Field and Temperature Monitoring

Yang

Mengue

Mishra

et al. 2021

Adv Materials Technologies

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wireless magnetic sensors are designed to detect magnetic anomaly and are used for street installation, traffic control, and detection of the parking space availability. The sensor responds to changes in the earth's magnetic field caused by the presence of a vehicle, generally a metallic structure. Installation would be easier and cost-effective if the sensors are batteryless and could be installed into the asphalt or pavement (i.e., buried), thereby eliminating the risk of degradation and the need for regular maintenance, particularly the change of batteries. Another application example for wireless magnetic sensors concerns remote electric current sensing including transient-state electric currents on overhead power lines. Indeed, the development of smart grids requires the development of reliable and low-cost sensor networks. Monitoring electric currents at present and especially in medium and high voltage power lines is difficult and expensive when installing conventional sensors. [1,2] The indirect measurement of electric currents through the generated magnetic fields is an elegant solution. The sensor must also be insensitive to the temperature of the wire that strongly depends on the electric current flowing.Surface acoustic wave (SAW) devices are key components in communication systems and are widely used as filters, delay lines or resonators. They are still relevant for the development of 5G compatible technologies. [3,4] Because SAW devices are highly sensitive to physical parameters that affect SAW velocities, they also offer promising solutions as sensors in a wide range of applications. [5][6][7][8] SAW sensors have the advantage of being micro, passive, wireless, and even packageless in specific configurations. [9][10][11][12] SAW sensor technology allows simultaneous and independent measurement of temperatures and magnetic fields (i.e., electric current). SAW devices based on ferromagnetic films have been studied for the development of magnetic field and electric current sensors. [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] However, the environment temperature is a factor affecting the performance of SAW sensors. An unavoidable fact is that SAW magnetic field sensors without temperature compensation are sensitive to both magnetic fields and temperatures due to the negative temperature coefficients of ferromagnetic films. [26,29] It leads to a difficulty in discrimination between them or their simultaneous measurement. Therefore, a SAW sensor that measures A one-port surface acoustic wave (SAW) resonator based on Co 40 -Fe 40 -B 20 / SiO 2 /ZnO/quartz multilayer structure and exhibiting a dual mode, Rayleigh and Love wave modes, is investigated to achieve a multifunctional sensor measuring both temperatures and magnetic fields. The Rayleigh wave mode of the resonator is used for temperature measurement with a temperature sensitivity of −37.9 ppm/°C, and the Love wave mode is used for magnetic field measurement. Co 40 -Fe 40 -B 20 is the magnetic sensitive layer, and quartz crysta...

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Sensing Mechanism of Surface Acoustic Wave Magnetic Field Sensors Based on Ferromagnetic Films

Cited by 8 publications

References 29 publications

Phase Noise of SAW Delay Line Magnetic Field Sensors

Phase Noise of SAW Delay Line Magnetic Field Sensors

Enhanced Sensitivity of FeGa Thin-Film Coated SAW Current Sensor

Wireless Multifunctional Surface Acoustic Wave Sensor for Magnetic Field and Temperature Monitoring

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