Antenna designer's notebook: Directional array for near-vertical-incidence skywave (NVIS)

摘要

Arrays of two and four horizontal dipoles were used to achieve higher efficiency and vertical gain for several conductivities. These designs were compared to a single horizontal dipole. The four-horizontal-dipole array could be pointed 34?? away from the vertical. The efficiency was reduced by only 1 dB. The groundwave was computed for all of the designs. The peak magnitude of the groundwave did explain the improved antenna efficiency. The antenna efficiency could be dramatically improved by increasing the antenna's height or operating frequency.