Finite Element Method on Mass Loading Effect for Gallium Phosphate Surface Acoustic Wave Resonators (original) (raw)
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Acoustic Wave Resonator. Resonant frequency
2009
Abstract—Mass loading has been one of the major parameter need to be consider before any of a surface acoustic wave devices can be fabricate. In this paper a finite element method (FEM) study of the mass loading on gallium phosphate surface acoustic wave resonator was done for high temperature sensing applications. A comparison with the previous experimental work has shown that FEM can be used to determine the effect of mass loading to the center frequency of the surface acoustic wave resonator.
Fabrication of high temperature surface acoustic wave devices for sensor applications
Sensors and Actuators A: Physical, 2005
Surface acoustic devices have been shown to be suitable not only for signal processing but also for sensor applications. In this paper high temperature surface acoustic wave devices based on gallium orthophosphate have been fabricated, using a lift-off technique and tested for high frequency applications at temperatures up to 600 • C. The measured S-parameter (S 11 ) has been used to study the mass loading effect of the platinum electrodes and turnover temperature of GaPO 4 with a 5 • cut. The analysis of these results shows that the mass loading effect can be used to predict the desired resonant frequency of the SAW devices. Also two different adhesion layers for Pt metallisation were studied. Our results show that Zirconium is a more suitable under layer than Titanium.
High-temperature 434 MHz surface acoustic wave devices based on GaPO/sub 4
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2006
Research into surface acoustic wave (SAW) devices began in the early 1970s and led to the development of high performance, small size, and high reproducibility devices. Much research has now been done on the application of such devices to consumer electronics, process monitoring, and communication systems. The use of novel materials, such as gallium phosphate (GaPO4), extends the operating temperature of the elements. SAW devices based on this material operating at 434 MHz and up 800 C, can be used for passive wireless sensor applications. Interdigital transducer (IDT) devices with platinum/zirconium metallization and 1.4 m finger-gap ratio of 1:1 have been fabricated using direct write e-beam lithography and a lift-off process. The performance and long-term stability of these devices has been studied, and the results are reported in this paper.
Effect of Electrode Configuration on High Temperature Thickness Shear Gallium Phosphate Transducer
Proceedings, 2017
Gallium phosphate single crystal has a very stable thermal response, ideal for high temperature applications such as transducers for in-service monitoring of HT infrastructure in Power and Oil & Gas industries. Broadband transducers are designed to resonate with a specific mode of vibration within a frequency range of interest. This desired frequency response depends on how the transducer is mounted on the structure and the target defect sensitivity. Electrode configurations are defined to achieve the transducer design. This study investigates the parallel and wrap-around electrode configurations on the transducer response. An electro-mechanical finite element model was developed to analyse the transducer response and predicted a disparity in the modes of vibration between the two configurations within the same frequency range. This model was experimentally validated by measuring the displacement patterns using 3D Laser Doppler Vibrometry.
High-Performance Film Bulk Acoustic Wave Pressure and Temperature Sensors
Japanese Journal of Applied Physics, 2007
A film bulk acoustic wave resonator (FBAR)-based sensor for the simultaneous measurement of temperature and pressure with high sensitivity is fabricated and characterized. Temperature or pressure sensing is determined by the change in the series resonant frequency of the FBAR device when exposed to a measurement environment. For temperature sensing, measurement results show a sensitivity of 25.02 ppm/ C, a nonlinearity less than AE0:005% over the measurement range of 10 to 80 C, and a hysteresis within AE0:005% in one temperature cycle. In pressure sensing, measured results show a sensitivity of 336.2 ppm/ bar, a nonlinearity less than AE0:004% over the measurement pressure range of 0 to 2.07 bar, and a hysteresis within AE0:007% in one pressure cycle.
Design of a surface acoustic wave mass sensor in the 100 GHz range
Applied Physics Letters, 2012
A design for photoacoustic mass sensors operating above 100 GHz is proposed. The design is based on impulsive optical excitation of a pseudosurface acoustic wave in a surface phononic crystal with nanometric periodic grating, and on time-resolved extreme ultraviolet detection of the pseudosurface acoustic wave frequency shift upon mass loading the device. The present design opens the path to sensors operating in a frequency range currently unaccessible to electro-acoustical transducers, providing enhanced sensitivity, miniaturization and incorporating time-resolving capability while forgoing the piezoelectric substrate requirement.
Journal of Electronic Materials, 2019
This paper reports the effect of the design parameters of a solidly mounted film bulk acoustic resonator (SMFBAR) for better gas sensing performance. The electrical equivalent circuit of the proposed device has been developed with the help of a Butterworth Van-Dyke (BVD) circuit. The electro-mechanical response of the SMFBAR has been obtained with the help of 3-D finite element method (FEM) analysis. The analytical modeling and FEM simulation results are compared. The physical parameters of the proposed design such as piezoelectric layer material, its thickness, active area of the device and sensing layer thickness affecting the characteristics of the SMFBAR have been investigated in detail. To achieve enhanced sensitivity, the variation of square active area has been analysed with one side dimension ranging from 700 lm to 300 lm. Gas sensing performance of the proposed sensor is tested by exposing toluene gas concentration ranging from 0 ppm to 500 ppm and enhanced sensitivity of 20 kHz/ppm has been achieved and reported. Also, it is reported that the variation in ratio of electrode layer thickness to piezoelectric layer thickness results in improvement of coupling coefficient (k eff 2) up to 7.46%.
Thermal characterization of Surface Acoustic Wave devices
2013
Reliability of micro-electronic devices is one of the most important issues in mobile communication systems and is significantly influenced by the thermal behavior of the components. This study presents different schemes for thermal characterization of a half-section ladder-type Surface Acoustic Wave (SAW) filter which is acoustically passivated with a thick SiO2 layer. Unitarity violation quantifies the entire power loss in the device but is unfeasible regarding correlation to each resonator. The Temperature Coefficient of Frequency (TCF) characterizes thermally induced frequency shifts and has the potential to investigate the resonators' temperatures separately in first order. However, uncertainties arise using this indirect approach as soon as other effects causing a frequency shift play a role. Thermographic techniques such as Infrared Thermography (IRT) and Liquid Crystal Thermography (LCT) serve as direct measurement schemes eliminating inaccuracies inherent to TCF based evaluations and show good agreement with simulation results. Moreover, LCT and IRT provide spatially resolved temperature measurements of the component.