Two-dimensional phononic crystal with tunable narrow pass band: Application to a waveguide with selective frequency

The propagation of elastic waves in two-dimensional composite media composed of a square array of hollow steel cylinder embedded in water was discussed using the finite-difference time-domain method. It was found that a linear defect formed of a row of hollow cylinders in an array of filled cylinders produced an elastic waveguides that transmitted at the narrow pass band frequency. The analysis showed that the two tunable waveguides with different inner radii were employed to filter and separate two specific frequencies from a broad band input signal.