The Radiation Characteristics of a Vertical Half-Wave Antenna

Abstract

Extensive measurements have been made of the field distribution about a vertical antenna operating at 29 megacycles over sea water. With the help of a small, nonrigid airship observations were made at various altitudes which permitted the plotting of the space characteristic and the determination of the attenuation as dependent on altitude. The experimental results are compared with field intensities computed for the given physical conditions from the theoretical expressions of Sommerfeld and Strutt. Of interest is the manner in which the field is attenuated in the immediate vicinity of the ground plane and the marked effect on the general intensity distribution of the effective height of the antenna above ground.Details are given of the design of the apparatus required for carrying out the measurements.

Radiation Pattern of a Vertical Dipole over Sea and Setup for Measuring thereof

“…Analyses of such radiating structures are mainly based on the numerical methods implemented by simulation software as a powerful tool for solving the shipboard electromagnetic problems [8][9]. However, actual measurements are of utmost importance, giving us the valuable insights into the physical phenomena and making possible the verification of the simulation and/or theoretical results [10][11][12][13][14].…”

“…The measurement setups described in literature were intended for specific problems and relied on considerable resources: in [11] the horizontal (azimuthal) radiation pattern was measured along the 4.6 NM long path from the ship to the shore, in [12] the vertical (elevation) pattern was measured using 70-foot high wooden arch above the antenna over sea, in [13] airborne measurements were done using a dirigible.…”