Insulated vertical antennas above ground

A fast efficient method is proposed to solve the problem of a vertical dielectric-coated antenna located in free space above ground. The solution is a moment method solution. The influence of lossy ground is taken into account via equivalent images due to Popovic, and the currents of images are expressed by the source current. The dielectric coating is modeled by equivalent polarization charges, which are simply related to the conduction current distribution. In this way, the dielectric coating and the lossy ground add no new unknowns to the problem solution, so the size of the impedance matrix for insulated antennas above lossy ground is the same as that for bare wires in free space. With reasonable approximation, the computation speed is improved enormously compared with the conventional method involving time-consuming volume, surface, or Sommerfeld-type integrations. The results obtained exhibit excellent agreement with those obtained by rigorous methods or experiment.