Plane-Wave Generators: Design Guidelines, Achievable Performances and Effective Synthesis

The aim of this paper is to investigate the main aspects of the synthesis of plane wave generators (PWGs) i.e., arrays capable of emulating a plane wave, or a superposition of plane waves, in a given region. In particular, we introduce new figures of merit, particularly suitable for PWG synthesis procedures, and simple guidelines regarding size and shape of the PWG, as well as the number of radiating sources needed to synthesize the required plane waves. The performance limits of a PWG are analyzed, in terms of indexes related to the stability of the solution and to the level of the field amplitude on the lateral walls of the anechoic chamber in which the PWG is placed. Finally we present a syn- thesis method for PWGs, based on a planar sparse array architecture. Starting from the previously achieved results, a novel effective synthesis procedure is introduced. By means of such a procedure we are also able to take explicitly into account the mechanical and electrical tolerances in the PWG realization. In such a way we can assure the best performances, given the unavoidable errors in the positioning and excitation of the radiating elements.