Analytical Methods for Antenna Analysis and Synthesis in the Time Domain

We consider two formulations for time domain (TD) antenna theory. The first one is a plane wave analysis in the TD and is based on the slant stack transform (SST) of the current distribution, while the other is based on a TD multipole expansion. The first formulation provides a complete far-zone characterization of transmit-receive antenna systems as a cascade of convolution operators of the TD effective heights. Using the other formulation we consider new near field concepts such as TD radiative and reactive fields and energies, and introduce the ratio between them, termed the TD Q, as a measure of the radiation effectiveness. The theory is used to evaluate and compare different realizations of highly collimated, short-pulse aperture distributions.