Surface wave excitation study

Relative Communication Efficiency (RCE) as defined by Fenwick and Weeks was used for the results discussed here. RCE compares the field of a test antenna to that of a reference antenna at the same location for equal input power to each antenna. Thus, RCE is similar to power gain but is definable in the presence of ground. The main purpose of this study was to compare the effectiveness of antennas in launching TM surface waves. Antennas considered included the vertical dipole, monopole on a ground stake, monopole on a radial-wire ground screen, Beverage antenna and vertical half rhombic. Since the performance of these antennas is strongly dependent on parameters such as the number of wires in a ground screen or the length of a Beverage antenna, results are presented with parameters varying over a reasonable range. Thus, antenna performance can be weighed against the effort and limitations of construction.