Accession Number : AD0712676


Title :   BROADBAND CONSTANT BEAMWIDTH ACOUSTICAL ARRAYS.


Descriptive Note : Technical memo.,


Corporate Author : TEXAS UNIV AUSTIN ELECTRONICS RESEARCH CENTER


Personal Author(s) : Hixson,Elmer L. ; Au,Kim-Tung


Report Date : 01 MAY 1970


Pagination or Media Count : 44


Abstract : The beamwidth of most directional receivers decreases with frequency. If broadband signals are used and accurate pointing is not maintained, spectrum shape is not preserved. Constant beamwidth arrays to prevent this problem are proposed here. When the output of an array is combined with the output of a half scale model of the array through the proper filters, constant beamwidth over an octave frequency range results. This process is continued to provide the desired bandwidth. A three element-two octave microphone array is described and its characteristics presented. Although the correct filters were not available, only plus or minus 8 degrees variation in beamwidth from 500 Hz to 2 KHz was achieved. Further study is recommended and application to many systems is suggested. (Author)


Descriptors :   (*VOICE COMMUNICATIONS, ANTENNA ARRAYS), (*ANTENNA ARRAYS, BROADBAND), FREQUENCY SHIFT, ATTENUATION, RESPONSE, GRAPHICS, ELECTROMAGNETIC WAVE FILTERS


Subject Categories : ELECTRICAL AND ELECTRONIC EQUIPMENT
      VOICE COMMUNICATIONS


Distribution Statement : APPROVED FOR PUBLIC RELEASE