Synthesis of Low and Equal-Ripple Sidelobe Patterns in Time-Modulated Circular Antenna Arrays

Abstract

In this paper, the time modulation technique is applied into circular antenna arrays with uniform amplitude excitations for the synthesis of ultra-low sidelobe and equal-ripple radiation patterns. The differential evolution (DE) algorithm is adopted to optimize the excitation phases and the switch-on time intervals of each element of the time-modulated circular array (TMCA). Several low-sidelobe patterns synthesized from TMCAs were compared to those of the conventional circular arrays. Numerical results show that the TMCA can be successfully used for the synthesis of low SLLs even if the amplitude excitations are uniform.