In:
The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 63, No. 3 ( 1978-03-01), p. 841-847
Abstract:
Simulated beam patterns and the directivity indices of a particular 97-element conformal array configured on less than half the surface of a quasiright circular cone have been studied. A comparison of two methods to calculate directivity index was made as a function of frequency and steering angle. At broadside, a directivity index of 19.54 dB was obtained for this conformal array. This value exceeds that of a conventional planar array which could be enclosed in the same-sized circular aperture by more than 3 dB. The technique to calculate directivity index which sums the correlation coefficients among discrete array element pairs avoids both the computer evalution expense and the sensitivity to approximation errors inherent in numerical integration procedures required to evaluate the volume under the directed array response. For this array, it was found that the directivity index did not fall off as rapidly as predicted for a planar array, of the same area as the conformal array, as the beam is steered from broadside to endfire. The expression 10 log10N was found to be useful in readily evaluating the directivity index, where N is the number of elements.
Type of Medium:
Online Resource
ISSN:
0001-4966
,
1520-8524
Language:
English
Publisher:
Acoustical Society of America (ASA)
Publication Date:
1978
detail.hit.zdb_id:
1461063-2
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