V. I. Melnichuk - PhD student of Moscow Institute of Physics and Technology, engineer, JSC «Radiofizika»
A. V. Shishlov - PhD, head of department, JSC «Radiofizika», deputy head of chair radiophysics and technical cybernetics, Moscow Institute of Physics and Technology

Efficiencies of contoured areas coverings by antennas synthesized by means of amplitude-only, phase-only and amplitude-and-phase methods are considered. Coverage efficiency factor defined as the ratio of minimum directive gain in a service area and ideal directive gain is considered as a main criterion of efficiency. Sidelobe level, gain variations within the service area and slope width of the main lobe are assumed as spare efficiency criteria. Radiation patterns were synthesized for contoured areas (sectors in the case of two-dimensional problem) of different width by employing different methods: amplitude-only synthesis, phase-only synthesis (one option is based on geometrical optics, the other one is based on numerical optimization), amplitude-and-phase synthesis (one option is based on partial radiation patterns method, the other one - on numerical optimization). Radiation patterns synthesized according to geometrical optics were used as initial approximations for optimization procedures both in phase-only and amplitude-and-phase methods. Theoretical estimations of coverage efficiencies are done for phase and amplitude-and-phase approaches, assuming that the radiation pattern is a trapezoid. The results of numerical modeling reveal that values of efficiency of contoured area coverings by synthesized radiation patterns coincide with theoretical estimations with accuracy of 0.1-0.15 dB for wide areas containing many beam widths of the cophased aperture. Comparison of radiation patterns synthesized by amplitude-and-phase method and phase-only method show that the first method yields better coverage efficiency, significantly lesser sidelobe level and slope width of main lobe compared to the first method. Amplitude-only synthesis allows to use simple antenna constructions but it is behind the former two methods in terms of coverage efficiency, beam efficiency, gain variations within a service area, and main lobe slope width.