Far-field focusing of acoustic waves by a two-dimensional phononic crystal with surface grating

2009 ◽  
Vol 87 (5) ◽  
pp. 57003 ◽  
Author(s):  
Zhaojian He ◽  
Xiaochun Li ◽  
Ke Deng ◽  
Jun Mei ◽  
Zhengyou Liu
Keyword(s):  
Acoustic Waves ◽  
Phononic Crystal ◽  
Far Field ◽  
Two Dimensional ◽  
Surface Grating

A Novel Micromechanical Resonator Using Two-Dimensional Phononic Crystal Slab

2011 ◽  
Vol 254 ◽  
pp. 195-198
Author(s):  
Nan Wang ◽  
Fu Li Hsiao ◽  
Moorthi Palaniapan ◽  
Ming Lin Julius Tsai ◽  
Jeffrey B.W. Soon ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Phononic Crystal ◽  
Acoustic Resonance ◽  
Two Dimensional ◽  
Free Standing ◽  
Sensing Applications ◽  
Aln Film ◽  
Digital Transducers ◽  
Square Array ◽  
Quality Factor Q

Two-dimensional (2-D) Silicon phononic crystal (PnC) slab of a square array of cylindrical air holes in a 10μm thick free-standing silicon plate with line defects is characterized as a cavity-mode PnC resonator. Piezoelectric aluminum nitride (AlN) film is deployed as the inter-digital transducers (IDT) to transmit and detect acoustic waves, thus making the whole microfabrication process CMOS-compatible. Both the band structure of the PnC and the transmission spectrum of the proposed PnC resonator are analyzed and optimized using finite element method (FEM). The measured quality factor (Q factor) of the microfabricated PnC resonator is over 1,000 at its resonant frequency of 152.46MHz. The proposed PnC resonator shows promising acoustic resonance characteristics for RF communications and sensing applications.

Far-field imaging of acoustic waves by a two-dimensional sonic crystal

2005 ◽  
Vol 71 (5) ◽  
Author(s):  
Chunyin Qiu ◽  
Xiangdong Zhang ◽  
Zhengyou Liu
Keyword(s):  
Acoustic Waves ◽  
Far Field ◽  
Two Dimensional ◽  
Sonic Crystal ◽  
Field Imaging

scholarly journals Experimental study of guiding and filtering of acoustic waves in a two dimensional ultrasonic crystal

2005 ◽  
Vol 220 (9-10) ◽  
Author(s):  
Abdelkrim Khelif ◽  
Abdelkrim Choujaa ◽  
Sarah Benchabane ◽  
Bahram Djafari-Rouhani ◽  
Vincent Laude
Keyword(s):  
Band Gap ◽  
Acoustic Waves ◽  
Theoretical Study ◽  
Phononic Crystal ◽  
Wide Frequency Range ◽  
Two Dimensional ◽  
Full Band ◽  
Side Walls ◽  
Difference Time ◽  
Good Agreement

AbstractWe present a combined experimental and theoretical study of the guiding, bending and filtering of acoustic waves in an ultrasonic crystal. The crystal consists of a two-dimensional periodical array of steel rods immersed in water, for wich a complete acoustic band gap extending from 240 to 325 kHz is found experimentally. Waveguides for acoustic waves are further created by removing a line defect, on which stubs can be added by removing rods from the side-walls of the waveguide. Full transmission is observed for a one-period-wide straight waveguide within the full-band-gap of the perfect phononic crystal, i.e. for a waveguide aperture smaller than one acoustic wavelength. Waveguiding over a wide frequency range is also obtained for a one-period-wide waveguide with two sharp 90° bends. Finite-difference time-domain computations are found to be in good agreement with the measurements in all experimental configurations.

scholarly journals Negative Refraction of Acoustic Waves in a Two-Dimensional Phononic Crystal via FDTD Simulation

2009 ◽  
Vol 50 (5) ◽  
pp. 1004-1007 ◽  
Author(s):  
Tomoyuki Kurose ◽  
Kenji Tsuruta ◽  
Chieko Totsuji ◽  
Hiroo Totsuji
Keyword(s):  
Acoustic Waves ◽  
Negative Refraction ◽  
Phononic Crystal ◽  
Fdtd Simulation ◽  
Two Dimensional

Experimental observation of resonant filtering in a two-dimensional phononic crystal waveguide

2005 ◽  
Vol 220 (9-10) ◽  
Author(s):  
Jerôme O. Vasseur ◽  
Pierre A. Deymier ◽  
Maxime Beaugeois ◽  
Yan Pennec ◽  
Bahram Djafari-Rouhani ◽  
...  
Keyword(s):  
Transmission Spectrum ◽  
Acoustic Waves ◽  
Theoretical Calculations ◽  
Phononic Crystal ◽  
Stop Band ◽  
Side Branch ◽  
Two Dimensional ◽  
Transmission Coefficients ◽  
The Waves ◽  
Model Structures

AbstractTransmission of acoustic waves through a two-dimensional composite material made of PVC cylinders surrounded by air is measured experimentally. The spectrum presents a very large absolute band gap in the audible frequency range. A waveguide created inside this phononic crystal by removing a row of cylinders can transmit very efficiently the waves falling inside the stop band. We show the existence of deaf modes in the band structure of the linear waveguide. Resonant filtering is also demonstrated experimentally by coupling the waveguide to a side branch resonator of variable length. Frequency filtering is observed in the form of narrow dips in the transmission spectrum of the waveguide. Most of these observations compare favorably with theoretical calculations of dispersion curves and transmission coefficients of model structures using the plane wave expansion and the finite difference time domain methods. Narrow dips similar to those of the guide with resonator are also observed in the transmission spectrum of a waveguide with a sharp bend.

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