A novel table top, ultra wideband, time domain scattering range will be developed under this Research Initiation Award grant. A picosecond laser will be used to switch planar antennas photoconductively, generating and detecting picosecond bursts of freely propagating electromagnetic (EM) radiation. The EM pulses will have bandwidth extending over 10-80 GHz, and will allow one to obtain ultra-wideband scattering data in a single measurement. In this work new antennas that increase the radiated power and improve signal- to-noise will be designed and fabricated. These antennas will make feasible the measurement of the late-time response of low-Q targets. Additionally, optical fiber will be used to guide the optical pulses to the antennas, yielding a system in which the transmitter and receiver can be moved about arbitrarily. This new scattering range has bandwidth and flexibility that are not found in conventional scattering ranges, and uses no conventional microwave nor millimeter-wave equipment. Particular structures that will be investigated with this system include partially open cavities, layered media, and targets embedded in layered media. Calculations of short-pulse scattering in such environments will also be made for comparison with experimental results.
