Analytic Analysis of Transient Radiation From Phased Array Antennas in the Near- and Far-Field Focus Applications

This paper presents an analytical transient analysis of electromagnetic field radiation from a time-delayed and finite periodic array of antennas for the near-and far-field focused applications. The elemental current moments of array are assumed with a transient impulse input for the excitations whose signals are delayed to radiate near-zone focused fields. The transient field phenomena for each of the Floquet mode expansion were analyzed. The solution reduces to the case of far-zone field radiation by moving the focus point to the far zone. The analysis shows that the radiation exhibits an impulse field at the focused point, and finite pulses at locations away from the focus point. Phenomena of partial cylindrical wave functions have been observed.