Huffman code-fed omnidirectional acoustical arrays

The synthesis of linear and planar acoustical arrays of desired omnidirectional intensity patterns is considered. It is shown that an almost omnidirectional pattern results when a code with a sharp correlation function is used as the feeding sequence for the elements of the array. The properties of Huffman codes are described, with special attention to integer Huffman codes, and examples of linear and planar arrays fed by multiplied Huffman codes are presented. Huffman impulse-equivalent codes have very sharp correlation properties and are shown to result in good omnidirectional linear and planar acoustical arrays. The results have direct application to underwater acoustical communication systems, public address systems and acoustical measurements