High frequency radiation from truncated arrays of filamentary sources on a dielectric slab
Previously explored radiation phenomenologies pertaining to individual line sources on a dielectric slab and to finite arrays of line sources in free space are here combined to synthesize and parametrize radiation from finite line source arrays located on a dielectric slab surface. From rigorous analysis and subsequent high frequency asymptotics for the prototype periodic case with linear interelement phasing, we obtain an observable-based parametrization (OBP) which connects features in reference data with structural features of the (slab)-(line array) configuration via wave processes with different physical content. The OBP is derived by applying the Poisson summation formula to collectively restructure the sum of direct radiations from the slab-loaded line sources. The restructuring leads to fields which are parametrized in terms of Floquet mode (FM) beams, slab-guided leaky modes (LM) peaked by phase matching to the truncated FM, and edge diffractions from the ends of the truncated array. The OBP algorithm is validated by comparison with numerical reference data, and the parametrization provides choices for design and classification.