Radiation efficiency and input impedance of monopole elements with radialwire ground planes in proximity to Earth
Abstract
Plots are presented, of the radiation efficiency and input impedance of a thin quarterwave monopole element with a radial wire ground plane in proximity to flat lossy earth, as a function of the number and length of the radial wires, earth permittivity, and location of the earth's surface with respect to the ground plane. The method of moments models have certain advantages over models based on Monteath's compensation theorem or Sommerfeld's attenuation function. These advantages are as follows: current on the ground plane is determined rather than approximated by that for a perfect ground plane; results are valid not only for moderatelylarge ground planes but for electricallysmall ground planes; directive gain and radiation efficiency can each be determined separately rather than being lumped together as a product to yield the antenna power gain; ground plane edge diffraction is not neglected; and analytical conditions on evaluating Sommerfeld's integral are avoided.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 September 1991
 Bibcode:
 1991STIN...9222172W
 Keywords:

 Antenna Radiation Patterns;
 Attenuation;
 Impedance;
 Monopole Antennas;
 Permittivity;
 Terrestrial Radiation;
 Amplification;
 Dielectric Properties;
 Method Of Moments;
 Power Gain;
 Communications and Radar