RADIATION OF ULTRA-WIDEBAND ELECTROMAGNETIC PULSES BY PULSED EXCITATION OF RECTANGULAR ANTENNA

Rectangular (2.5 x 2 cm(2)) antennas fastened to an end of a transmission line were pulse-excited by 0.5 ns rise time pulses for radiation of ultra-wideband signals. Wideband horn antennas were used for receiving the signals and wideband sampling oscilloscope was used for their visualization. The signals were registered in 1-5.6 GHz frequency range and had the quasi-Gauss envelope form. The plane antennas made of Cu, resistive Al, and resistive nanostructured Ni thin films on supporting polyethylene terephthalate of 100 mu m thickness were used. It is shown that the radiation induced by pulsed excitation can be used to control parameters of resistive coatings, including nanostructured ones, during a deposition process. The metallic nanostructured thin films could be used to create plane radiating and receiving antennas having resistive elements and adapted for ultra-wideband signals. Ultra-wideband antennas with resistive nanostructured coatings, which have properties that can be changed by external electric or magnetic fields or by optical radiation, can be used for modulation of radiated pulses. Further experimental studies are proposed to elaborate metallic nanostructured thin films suitable to withstand possible damages induced by short high power electrical pulses.