MEASUREMENT OF ACOUSTIC STOP BANDS IN 2-DIMENSIONAL PERIODIC SCATTERING ARRAYS

The experimental observation of acoustic stop bands in two-dimensional periodic arrays using an impulse response technique is reported. The frequencies of the stop-band centers are consistent with simple theore tical considerations based on the spacing between layers along the hig h symmetry directions of the regular arrays. The phase information ext racted from the Fourier analysis is used to construct the acoustic dis persion relation for frequencies above and below the stop band. Measur ements are reported for both square and triangular scattering arrays. (C) 1998 Acoustical Society of America. [S0001-4966(98)01908-0]