Full-wave analysis of quasi-optical structures

Near-field and far-field prediction of quasi-optical grid arrays

“…The electromagnetic near and far fields can be computed from the current distribution on the grid array found from the MoM. In all of the results presented in this paper, the current distributions on the grid arrays are computed from the MoM technique presented in [2] and [3]. In the following sections, the formulations for computing the near and far fields are given.…”

“…The transverse components of the electric field are written as (1) where is the dyadic Green's function and is the current density. Expressions for the quasi-optical dyadic 0018-9480/99$10.00 © 1999 IEEE Green's functions are found in [2] and [3]. The and components of the electric field is then given by (2) and (3) where the and current density is defined as (4) and (5) The current density given in (4) and (5) is found from the sinusoidal basis functions used with the MoM [2] where is the current distribution computed from the MoM at each basis function having cell subdivisions of and in the -anddirections, respectively.…”

“…Since the MoM formulation was formulated using both the spatial and spectral domains in [2], the formulation for the electric field is also given in the spectral domain. First, the dyadic Green's function is related to the spectral-domain dyadic Green's functions through the inverse Fourier transform (6) where represents the spectral-domain Green's function.…”

“…The near-fields are computed in the spatial domain using (2) and (3) and in the spectral domain using (7) and (8). The evaluation in the spectral domain is needed for the singularities that occur in the self terms [2].…”

“…In [2], the authors presented a MoM technique for analyzing quasi-optical structures like the Fabry-Perot resonator and, in [3], they extended it to include finite grid arrays in a lens system. In this paper, polarizers are added, but more importantly, field profiles of the quasi-optical focussed lens system are computed and compared with measurements and utilization of the work in design is demonstrated.…”