Ultrasonic Add/Drop Filter based on Two-Dimensional Solid/Fluid Phononic Crystals

: In this paper, we focus on two-dimensional solid/fluid phononic crystal in megahertz range. The case of Ethanol rods embedded in a ceramic lattice has been computed. The plane wave expansion method is used to calculate the dispersion relations which are in good agreement with the transmitted sound pressure level spectra established by the finite element method. Results show that this structure exhibit some absolute bandgaps with suitable bandwidth. So with the help of adding suitable defects, and by introducing methyl nonafluorobutyl ether as a defect inclusion, perfect modes were obtained among bandgaps region. Also, by designing a quasi-periodic structure and with the help of coherent cavities, a distinct frequency was obtained. So, by combining a row of defect rods as a moderate waveguides and designed quasi-periodic structure, we led to the design of acoustic add/drop filter. The designed filter receives the frequencies range from f=1.47MHz to f=1.51MHz and send them in to one distinct output with high confinement and due to the quasi-periodic structure frequency f=1.498MHz is use as the add-drop frequency.