Power wave theory and its application to time and frequency domain antenna characterization

We develop here a minimal complete set of parameters that fully characterizes any antenna in the far field in both the time and frequency domains. These parameters emerge from power wave theory, which was originally motivated by the need to characterize antennas in the time domain. However, we found this theory also fills in significant holes in the characterization of antennas in the frequency domain. The antenna is assumed to have no nonreciprocal components, and to be embedded in a lossless medium. Our intention is to supplement the definitions included in IEEE Standard Definitions of Terms for Antennas. (IEEE Std. 145-1993, March 1993.)