Conformal antenna synthesis using spherical harmonic wavefunctions

A new antenna-synthesis method is described that allows the antenna surface geometry to be arbitrarily specified and the radiating current distributions to be computed directly from the radiation patterns, which can be quite general and have any type of polarisation: this latter process makes the synthesis procedure nonunique, but is of great practical value since phase information is not required. Illustrative examples based on rotational symmetry are given to show the effect of all the various sources of controllable error, and useful information is also extracted about the formulation of active conformal arrays of small closely spaced noninteracting radiating elements; in particular, a means of optimising a conformal beacon antenna and creating a wide bandwidth supergain system by utilising the closely spaced driven array principle is discussed.