Antenna coverage considerations for military communication

The author proposes a circularly symmetric antenna aperture distribution that optimally satisfies the somewhat conflicting requirements for a high gain radiation pattern everywhere within the coverage zone and low probability of intercept outside this zone. This is accomplished by simultaneously maximizing (1) the edge-of-coverage gain and (2) the fraction of the radiated energy that falls within the coverage zone. These requirements completely specify the aperture distribution and its size. Fifty percent of the radiated energy is directed into the half-power beamwidth in this design, and the edge-of-coverage gain is exactly 1/sin²θ, where θ is the half-power angle off-axis