Infinite phased-array analysis using FDTD periodic boundary conditions-pulse scanning in oblique directions

Unit cell analysis of infinite phased-arrays in the finite difference time domain (FDTD) is performed by implementation of periodic boundary conditions. The technique allows for pulse excitation and oblique scan directions in both the cardinal and intercardinal planes. To our knowledge, this is the first paper presenting FDTD computations for intercardinal pulse scanning in oblique directions. The ordinary Yee lattice is used, which makes the algorithm easy to incorporate in an already existing FDTD code. Nonperiodic boundaries are truncated by Berenger's (see J. Comput. Phys., vol.127, p.363-79, 1996) perfectly matched layer (PML). Active impedance of an infinite dipole array is calculated with the new method and validation is performed via the "element-by-element" approach, i.e., by a conventional FDTD simulation of a corresponding large finite array. Excellent agreement is found and the technique has been numerically stable in all cases analyzed.