Time-domain properties of phased array antennas

This paper describes initial findings from a research program to investigate the main beam and sidelobe impulse responses of large phased array antennas and reflector antennas typically used for radar applications. Particular emphasis is given to the way that the impulse response changes from the main beam to the sidelobe region of the antenna. Time-domain effects affect transmit and receive waveforms and therefore advanced signal processing algorithms such as adaptive digital beamforming (ADBF) and space time adaptive processing (STAP) are used. GTRI has instituted an internal research program to investigate the time-domain phenomenology of phased array antennas and develop computer simulation tools and measurement capability for characterizing these phenomena. We provide a brief discussion of the time-domain phenomena and the effects that antenna architecture produces. An overview of the method GTRI is using to investigate these phenomena is given. Finally, initial results of these efforts are presented.