KINEMATIC PROPERTIES OF SHORT-PULSED SPARSE TRANSMITTING ARRAYS

The kinematic properties of an array of transmitting antennas that are transiently excited by a sequence of modulated pulses, with high repetition rate, are explored. The array's parameterization is carried out via the energy radiation pattern. It is shown that the energy radiation pattern can be decomposed into a set of difierent types of beam contributions, deflned over a beam- skeleton, which is determined by the array's physical and excitation parameters. The difierent types of beams are main beams, grating- lobe beams and cross-pulsed lobe beams, each corresponding to a difierent pulsed interference mechanism. While grating lobes are time- harmonic phenomena, cross-pulsed lobes are unique for excitation with a pulsed sequence. The difierent beam types set limits for array sparsity in terms of the array's physical and excitation parameters. The array's directivity is introduced as a flgure of merit of its performance and to demonstrate the resulting efiect of the time-domain excitation characteristics. The array's parameterization can be used with any type of excitation | from extreme narrow band (time-harmonic) to extreme ultra-wideband (transient/short pulsed) excitation. For time- harmonic excitation, the resulting characterization matches that of the classical frequency domain antenna theory.