Analysis of the single wire fed dipole antenna

An antenna consisting of a single wire connection from a source to a half-wavelength dipole above a ground plane is studied. With the inherent simplicity of the structure in mind, and the frequent need to connect a dipole antenna to an unbalanced output port (e.g., coaxial or microstrip line), the authors examine the performance of one such antenna and discuss the implications for similar geometry feeds with microstrip patch antennas. Current distribution and radiation patterns are presented. A number of observations on the operation of antennas fed by single wires or probes oriented perpendicular to ground are presented. Although the current distribution on the feed wire appears to be uniform, the description of this wire as a transmission line or nonradiating feed is not correct The mechanism for the radiation from the feed wire is a traveling wave from the feedpoint to the junction with the dipole. Since the resulting radiating structure is asymmetrical, the radiation pattern is also asymmetrical.<>