Related Papers
Enhancement of the Quality Factor of AlN Contour Mode Resonators by Acoustic Reflection: Numerical Design and Experimental Investigation
Massimiliano Cremonesi, Attilio Frangi
Applied Physics A: …
Acoustic meta-materials in MEMS BAW resonators
2011 •
Xavier Rottenberg
ALN-ON-SI MEMS RESONATOR BOUNDED BY WIDE ACOUSTIC BANDGAP TWO-DIMENSIONAL PHONONIC CRYSTAL ANCHORS
Muhammad Wajih Ullah SIDDIQI
We report an AlN-on-Si Lamb wave resonator with a unique wide acoustic bandgap (ABG) phononic crystal (PnC) structure at its anchors that provides an almost 4-fold increase in quality factor (Q). We show that the wider ABG provides for greater suppression of anchor loss and thus higher Q relative to a narrower ABG. Compared to more common circular void PnC structures, the unique PnC structures presented herein based on solid disks offer a 9-fold increase in the ABG size (82MHz vs. 9MHz) at a similar center frequency around 142MHz. The measured improvements in Q over multiple devices are consistent with finite element simulations on tuning the ABG size.
Micromachines (Basel).
Wide Acoustic Bandgap Solid Disk-Shaped Phononic Crystal Anchoring Boundaries for Enhancing Quality Factor in AlN-on-Si MEMS Resonators
2018 •
Muhammad Wajih Ullah SIDDIQI
This paper demonstrates the four fold enhancement in quality factor (Q) of a very high frequency (VHF) band piezoelectric Aluminum Nitride (AlN) on Silicon (Si) Lamb mode resonator by applying a unique wide acoustic bandgap (ABG) phononic crystal (PnC) at the anchoring boundaries of the resonator. The PnC unit cell topology, based on a solid disk, is characterized by a wide ABG of 120 MHz around a center frequency of 144.7 MHz from the experiments. The resulting wide ABG described in this work allows for greater enhancement in Q compared to previously reported PnC cell topologies characterized by narrower ABGs. The effect of geometrical variations to the proposed PnC cells on their corresponding ABGs are described through simulations and validated by transmission measurements of fabricated delay lines that incorporate these solid disk PnCs. Experiments demonstrate that widening the ABG associated with the PnC described herein provides for higher Q.
EFFECT OF CURVATURE AND ELECTRODE COVERAGE ON THE QUALITY FACTOR OF BICONVEX ALN-ON-SI MEMS RESONATORS
Muhammad Wajih Ullah SIDDIQI
Journal of Applied Physics
Ultra-high frequency, high Q/volume micromechanical resonators in a planar AlN phononic crystal
2016 •
Mohammadhosein Ghasemi Baboly
Microelectronic Engineering
Nanometer scale gaps for capacitive transduction improvement on RF-MEMS resonators
2007 •
G. Abadal
Low Motional Impedance Bulk Acoustic Resonators Based on Metamaterials
2012 •
Harrie Tilmans
This paper presents the implementation of propagating acoustic metamaterials in electrostatically transduced Bulk Acoustic Resonators (BARs) to tune by design their characteristic properties. Novel in this paper is our focus on lowering the observed motional impedance (Rm), key parameter for the design of low phase noise oscillators based on these BARs. We report on the modelling, simulation (not presented in the abstract) and experimental verification of the implementation of periodic square patterns of square holes, i.e., vacuum/air inclusions, in order to decrease Rm for the first width extensional resonance mode of electrostatically transduced bar-type BARs. The Rm is proportional to the characteristic acoustic impedance of the resonator material, i.e., √(Eeffρeff), where Eeff is the effective Young’s modulus and ρeff the effective mass density of the resonator material. The larger the proportion of hole area in the equivalent metamaterial is, the lower ρeff and Eeff are, and th...
Design and analysis of MEMS-based metamaterials
2006 •
Amy Duwel
Metamaterials, materials that are constructed with arrays of small elements have significant potential to provide material properties that are useful for electromagnetic applications but are not found in nature. Slight changes to a repeated unit cell can be used to tune the effective bulk material properties of a metamaterial, replacing the need to discover suitable materials for an application with the ability to design a structure for the desired effect. However, most current metamaterial realizations are plagued by high loss, large size, awkward structure, or difficult construction. The use of Micro-Electro-Mechanical Systems (MEMS) to create a new metamaterial could improve upon some of these shortcomings due to their small size, high Q, and ease of integration into standard applications and circuit fabrication techniques. In this thesis, I analyze the prospects of a MEMS-based metamaterial. First, I determine the best type of MEMS resonator to use in a metamaterial. Then, I bui...
2011 9th IEEE International Conference on ASIC
Aluminum Nitride reconfigurable RF-MEMS front-ends
2011 •
jan van der spiegel
