An Easily Constructed VLF Transmitting Antenna

摘要

A moderately efficient, low cost, broad-band VLF transmitting antenna that can easily be consstructed over low-conductivity terrain is discussed. The antenna consists of 20 horizontal conductors 12 km in length that are arranged into four dipoles wavelength/2 apart which radiate a 26 degrees steeerable beam. The dipoles are 1 wavelength and are fed off-center to obviate vertical radiation; their radiation patterns and those of the four-dipole array are presented. Dipole input impedances and antenna efficiency at 20 kHz are derived; antenna voltage and current at 1 MW input power are shown to be satisfactory. (Author)