NON-PLANAR ARRAY 'THINNING' STUDY.
Abstract
An investigation was made to establish guide-lines for designing thinned, nonuniformly spaced array antennas of spherical or hemispherical configuration. The main accomplishments during this reporting period are: (a) Development of analytical expressions for the means and variances of the normally distributed quadrature components of the far field for a randomly thinned spherical array with a radius of about 60 wavelengths, using one-quarter of the sphere as an active cap. Simple, closed-form approximations are available for the main beam and close-in sidelobes; (b) preparation of programs for the general-purpose computer which will generate far-field patterns for spherical arrays thinned to any desired percentage fill and using various degrees of element directivity. Final debugging of these programs is nearing completion; (c) progress toward the development of analytical expressions, valid for any angle theta sub p off the main-beam axis, for the means and variances of the far field as functions of theta sub p and progress toward a valid analytical technique for estimating the probability that no sidelobe in a prescribed range of theta sub p exceeds a specified level; (d) a start on the evolution of thinning schemes which simultaneously (1) preserve the 60-fold symmetry inherent in the icosahedral partitioning technique for establishing element locations, and (2) permit the important pattern parameters to be estimated on a statistical basis as for purely randomly thinned arrays. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1965
- Accession Number
- AD0614906
Entities
People
- Charles E. Clarke
- Thomas J. B. Shanley