Pattern synthesis for equal-gain coverage in air-to-ground communication

In this article, a new strategy for high-quality and wide-coverage air-to-ground communication is proposed by using pattern synthesis method. The cosecant pattern for equal-gain coverage is synthesized using two switchable patterns, which are provided by switchable feeding networks and a ten-element airborne microstrip antenna array. The merits of the proposed strategy include two folds: first, the antenna array and feeding network are easy to design and with low cost, no need to use beam steering method. Second, the maximum available gain in the required cosecant coverage is achieved by the proposed strategy, providing sufficient path loss margin. We have simulated and fabricated the array prototype, and measured results have proved our idea to achieve equal-gain coverage with a relatively simple antenna structure.