A Reflector Antenna for Radiating Impulse-Like Waveforms

P2ww'd'el e @@& .4 paraboloidal reflector antenna fed by a pyramidal horn has found widespread application in radar and communication engineering. However, the reflector antenna has very useful characteristics when it is fed or illuminated by two or four-conductor transmission lines. We have am.lyzed, designed, fabricated, and tested a reflector antenna fed by a pair of conical transmission Iines connected in parallel at the focal point. The voltage waveform at the apex of the lines, is a fast rising (~ 100 ps), slowly decaying (N 20 ns e-fold) pulse with a peak amplitude of about 125 kV. The calculated and measured radiated field at a distance of 304 m is impulse-Like with amplitude of about 4.2 kV/m and a pulse duration of < 200 ps. The resultant wide spectrum of the radiated field, extending from about 50 MHz to few GHz, is expected to fl.nd many applications in areas such as hostile target. identification, buried object detection, high-power j amming etc.