Selective targeting: developing a space time array to increase the peak power delivered to a localized region in space

In this paper, an approach is presented for producing a high concentration of electromagnetic energy into small regions involving free space or non-dispersive materials. The technique utilizes an array of ultra-wideband antennas radiating short duration pulses. It is shown that precise control of the time delays of the pulses radiated from the individual elements allows selective targeting of regions in space where the pulses may overlap in a coherent fashion. This approach is similar to using time delays for array beam steering. In fact, as the target area is moved away from the array into the far zone, the focusing of power into small regions deteriorates into a beam steering problem.