Suppression of side lobe level on the cone characteristics of the directivity pattern of an antenna as an important factor in its directivity index and effective aperture

Abstract

This paper will present a universal procedure for precise de‐embedding of the directivity index and effective aperture dependence of the suppressed side lobes on measured cone directivity patterns of sonar antennas. The procedure is derived on an idealized model of cone characteristics and directivity patterns of antennas. It is universally applicable to any contemporary sonar or hydroacoustic communication system with a cone directivity pattern. In accordance with the given expressions of directivity index and effective aperture of circle baffled pistons, this paper will present substitute analytical functions for hypothetical circle antennas with suppressed minor lobes. The presented graphs of functional behavior in a two‐dimensional system, and in a three‐dimensional coordinate system, are an excellent base for standardization, unification and quality evaluation of sonar or radar systems and also medical scanners. Key words: directivity index of sonar antenna, idealized model of cone directivity pattern, level of suppressed side lobes, effective aperture