Design of circularly polarized ultra-wideband aperiodic antenna arrays

For simplicity, most ultra-wideband aperiodic array layout design approaches use only isotropic sources as elements during optimization. However, since the selected antenna element can have a large impact on the total radiation pattern of the final array, it would be beneficial in such cases to use realistic antenna element patterns when designing array layouts. In this paper, a realistic spiral antenna is used in the design of aperiodic ultra-wideband antenna arrays with special attention paid not only to peak sidelobe level but axial ratio as well. The covariance matrix adaption evolutionary strategy is utilized together with an efficient pattern multiplication technique to optimize the locations and rotational configuration of spiral elements in 75-element arrays. A method of moments solver is employed to validate the optimized designs.