Pattern Synthesis with Specified Broad Nulls in Time-Modulated Circular Antenna Arrays

This article presents an approach for the synthesis of time-modulated circular array patterns with specified null width constraints. The time-modulated circular antenna arrays with uniform amplitude excitations are designed through the differential evolution algorithm with their excitation phases, and the switch-on time intervals of each element of the time-modulated circular arrays are the variables to be optimized. Several examples synthesized from the time-modulated circular array with the prescribed null width and depth are compared with some published results of the conventional circular array. Simulation results illustrate the achievable performance of the approach in successfully synthesizing patterns with desirable broad nulls, even if the amplitude excitations are uniform.