The control of acoustic-frequency gaps by altering the geometry of the system is analyzed in the particular case of a set of parallel solid square-section columns distributed in air on a square lattice. This system is shown to be sensitive enough to the rotation of the columns to be considered for practical sonic band-gap-width engineering. For different geometric configurations, specific interpretation models are used, taking into account the important mismatch of the impedance between the compounds. The accuracy of the plane-wave calculation is discussed in the different cases.

• Received 8 January 2001

DOI:https://doi.org/10.1103/PhysRevB.64.075118