Radiation characteristics of a linear array antenna for a ground-wave radar at a coastal site

The moment method is used to calculate the radiation pattern of a linear array for a number of array element configurations which include single monopole whips, single diamond shaped monopoles and three-element Yagi monopole whips over a perfect ground plane. Investigation of the far field radiation pattern is carried out for the cases of main lobe steering and pattern shaping (using Tschebyscheff polynomial). The effect of varying the frequency on the radiation pattern is also studied. Results show that the linear array with Yagi monopole elements has larger gain and less reception from high altitudes than the linear array with quarter-wavelength monopole whips. Diamond-shaped monopoles have wider frequency band than the single whips, and their individual pattern may help suppress grating lobes in some higher frequency ranges.