Compact Ultra - Short Pulse Fuzing Antenna Design and Measurements

We consider here antemas that could be usefid as part of a fize radar for penetrating munitions. The concept requires radiating an ultra-short pulse using an antenna with maximum gain and a compact design. Both lens and reflector Impulse Radiating Antennas (IRAs) are recommended as suitable candidates for this purpose. We summarize the properties of these antennas, and we describe two measurement techniques for determining their characteristics. The first technique involves a single antenna and a large planar reflector; the second technique uses two identical antennas. We have built a pair of reflector IRAs with F/D= 0.25 and diameter = 46 cm and measurements were performed using both of the techniques described. In addition, since propagation issues will also be important to such a radar system we sketch out some of the available analytical and numerical models of pulse propagation through frequency-dependent dielectric media. IVnally, we suggest experimental configurations for measuring these propagation characteristics.