ISCAN - Inertialess steerable communication antenna

The main purpose of the new antenna system, described herein, is to enhance high-frequency communications by reducing the effects of multipath and interference. The experimental ISCAN system, designed for reception of long distance h-f communications, consists of two principal parts: a linear array of vertical dipoles over 6300 feet long and an electronic beam forming matrix. A single, fixed-beam radiation pattern is available at each of the 14 terminals of this matrix. The beams have the shape of coaxial conical shells and adjacent beams overlap each other at the half-power points. These beams are formed by the use of tapped delay cables which is an inherently broadband method. Inertialess scanning of an antenna beam is achieved by rapid switching of the 14 beams in sequence using electronic gating circuitry. This effectively scans the antenna beam up to 30 degrees off the array axis. A visual oscilloscope display is provided to show the relative outputs of the multiple beams at all times.