Realization of Low Sidelobe Level Sparse Array Antennas Using Fractal Structures

This article discusses the novel application of fractal geometries in the realization of uniformly fed (isophoric) sparse array antennas with low sidelobe level (SLL). A fractal sparse array antenna allows the realization of wide bandwidth of operation, wider scanning capabilities, multi-functionality, and reduction in the overall number of elements along with ECCM capabilities. The present work focusses upon the realization of the concentric ring sparse array antenna using fractal structures. It demonstrates high sparsity and low SLL features in the resulting designs and discusses the various test cases to illustrate the design process and the roles of the design variables as identified in controlling the array's radiation performance. Thus, these have great applications in various wireless applications like 5G/6G mobile telephony, smart wireless power transfer (WPT), radars, etc.