Conformal array realizations of the near and far fields of a complex point source

Abstract

The complex point source radiates an unusual field without sidelobes in both the near and far zones. The field on a sphere in the near zone closely resembles the far-field pattern. These properties make the complex point-source field desirable in numerous applications in electromagnetics and acoustics. The complex point-source field will be generated using non-resonant arrays with properties that can be realized in the laboratory. Both standard and weighted least-squares techniques determine the array excitation coefficients. The number of array elements required to achieve a certain accuracy of the radiated field can be dramatically reduced if a conformal array structure is employed with the array elements mounted on an impenetrable object. Only the part of the impenetrable object that faces in the beam direction need to be populated with array elements. Numerical examples with array elements consisting of real point sources mounted on a Dirichlet sphere illustrate these findings.