Deterministic Reduced-Order Macromodels for Computing the Broadband Radiation-Field Pattern of Antenna Arrays in FDTD

The enhanced nodal-order reduction (ENOR) technique is used to perform model-order reduction (MOR) on a macromodel of a subgridded finite-difference time domain (FDTD) region which contains the deterministic fine structural features [1] of an aperture antenna array laying in a larger and relatively coarser FDTD grid, to solve the broadband time-varying electromagnetic fields emanating from the antenna array and to obtain the far-field radiation patterns. The far-field radiation pattern computed in FDTD is correlated against results computed through physical optics approximation. This work lays the foundation for a separate but related work to follow, in which we further develop the above deterministic macromodel into a stochastic macromodel that addresses the problem of uncertainty in fine features of structures with disparate spatial scales.