Band gaps of thin phononic crystal plates with complex square-like lattice

A thin phononic crystal plate with complex square-like lattice and five circular scatterers in its unit cell was studied. Longitudinal vibration band gaps of this plate were calculated with the plane wave expansion method.Numerical results showed that the width and location of the band gaps can be tuned by changing the filling fraction and the radius ratio of scatterers at different positions in the unit cell; comparing to the square lattice and Bathroom lattice with the same filling fraction,a wider gap can be obtained with the complex square-like lattice under an appropriate radius ratio.