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Slow thickness shear vibrations in AT-cut quartz plates driven by a lateral electric field produced by surface electrodes are analyzed theoretically. Mindlin's first-order theory of piezoelectric plates is used. Through an electrically forced vibration analysis, the motional capacitance and mode shapes near resonances are obtained. The effects of the electrode gap, the electrode/plate mass ratio R...
In the design and optimization of quartz crystal resonators, the finite element method has been adopted for the analysis of quartz crystal plates with complications for the vibration frequency and mode shapes. Further extension of such analysis can be made by using complex solutions to extract the electrical parameters of quartz crystal resonators because it is a typical electronic component in circuit...
This paper analyses free vibration frequencies and modes for thickness-shear and thickness-twist vibrations of centrally partially electroded circular AT-cut quartz plate by using 3-D finite element models of commercial package ANSYS. The analysis has been done with the 3-D Finite Element Analysis (FEA) for displacements and vibration frequency at the thickness-shear mode, which is important in the...
This paper mainly analyzes the fundamental and third order thickness shear modes of z-strip quartz resonator with the scalar equations derived by Tiersten and Smythe. Effects of the mass ratio and the length of the electrode on the operation modes and resonant frequencies are also studied. Exact modes can be obtained and the results show that the operation modes without nodal lines on the electroded...
We present a theoretical and experimental study of L-band (1–2 GHz) Lamb mode resonators in Gallium Nitride (GaN) monolithic microwave IC technology. These resonators leverage Au-free metallization and optimized anchors, enabling f·Q products up to 5.5×1012, the highest reported in GaN resonators to date. These devices also demonstrate the highest electromechanical coupling (keff2 of 0.39%) measured...
Background: It is desired to grow AlN in a reversed c-axis configuration to fabricate R-FBARS (Reversed c-axis Film Bulk Acoustic Resonator) with reactively sputtered, thin film Aluminum Nitride (AlN). Previous methods of growing reversed c-axis AlN, result in films with low electro-acoustic coupling constant, low Q, or inability to withstand the Avago Technologies FBAR release process. Conribution/Methods:...
We propose a new way to temperature compensate solidly mounted bulk acoustic wave resonators (SMRs). With the proposed process high Q, high electromechanical coupling coefficient, fully temperature compensated resonators have been successfully fabricated with TCF less than 1 ppm/??C and total thermal drift of less than 35 ppm across the temperature range from 0-100??C.
In this paper, a MEMS energy harvester was investigated to scavenge power from ambient vibration source. It was designed to convert low level vibration to electrical power via the piezoelectric effect. The proposed energy harvester was fabricated by patterning Pt electrodes into inter-digital geometry on top of the sol-gel-spin coated Pb(Zr, Ti)O3 thin film for d33 mode on silicon cantilever with...
A novel concept for shear mode Bulk Acoustic Resonators (BAR) is presented. It is based on c-axis oriented AlN thin films grown on silicon dioxide thin films, combined with interdigitated electrodes. Such a structure leads to an excitation of mainly shear mode displacements in the AlN film. However, a more pure mode is expected if only every second electrode section would contain active AlN, thus...
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