Performance of Ground-Based High-Frequency Receiving Arrays with Electrically-Small Ground Planes

Abstract

Electrically-small ground planes degrade the performance of ground-based highfrequency receiving arrays because the arrays are more susceptible to earth multipath, ground losses, and external currents on element feed cables. Performance degradations include a reduction in element directive gain near the horizon, distortion of the element azimuthal pattern, an increase in the system internal noise factor, and increases in the array factor root-mean-squared (rms) phase error and beam-pointing errors. The advantage of electrically-small ground planes is their relatively low cost of construction and maintenance. iii,-- k-------

Validation of the Numerical Electro-Magnetics Code (NEC) for Antenna Wire Elements in Proximity to Earth

“…NEC-GS results (for a 128 radial-wire ground plane) are in close agreement with results from Richmond's method-of-moments program RICHMOND4 [17,19] (for a disk ground plane) when computing the radiation efficiency of a quarter-wave monopole element with a small ground plane on or in close proximity to medium dry Earth (see figure 7).…”

“…The surface wave, with an evanescent field in the air-medium only, leaks energy into the earth medium but not into the air medium [17,18] However, even for a case where directive gain is correctly given by a Fresnel reflection coefficient model, the power gain (= directive gain x radiation efficiency) is incorrectly given because the radiation efficiency is grossly overestimated by the Fresnel reflection model. …”

Influence of nonhomogeneous Earth on the rms phase error and beam‐pointing errors of large, sparse high‐frequency receiving arrays

“…The performance of ground-based HF antenna arrays is reduced when the array elements have electrically small ground planes [Weiner, 1991b].…”

Radiation efficiency and input impedance of monopole elements with radial-wire ground planes in proximity to Earth

“…A more detailed discussion of the electrical characteristics of antennas with electrically-small ground planes in proximity to earth is given in Ref. [12]. …”