Directive Properties of Radiating Source Systems in Massive Electromagnetism

We investigate the problem of electromagnetic radiation in massive electromagnetism with focus on the directive radiation characteristics of Proca antennas (sources embedded into Proca metamaterial domains.) It is theoretically demonstrated that the recently proposed nonlocal Proca metamaterial implies the existence of point nonlocal sources possessing a perfectly isotropic radiation pattern. Based on this rigorous analysis, we derive exact expressions for the directive radiation patterns of arbitrary discrete distributions of Proca sources, i.e., radiating arrays emitting massive photons. Examples of linear discrete Proca arrays are given and comparison with massless photon radiation sources is provided.