Multiobjective Synthesis of Ultra-Wideband Array Antennas in the Time Domain With High-Power Pulse

Abstract

Ultra-wideband (UWB) is a typical high-power electromagnetic (HPEM) interference environment. The important parameters that affect the performance of UWB HPEM simulators include electric field strength ($E_{pp}$), waveform consistency ($t_{ppvar}$), and test space (half-power beamwidth (HPBW)). In this letter, the constrained multiobjective optimization algorithm NSGA-II is used to optimize the time delay of the array element based on the principle of convolution of time domain array patterns. The appropriate solution on the Pareto front according to the actual need is used to realize a stable radiation field with a certain amplitude over a larger test space. Under one of the sets of delays, the $E_{pp}$ of this array is reduced by no more than 70% and the HPBW is increased from 16.1° to 24°. The rate of change of pulse width is reduced from 21.5% to 5% corresponds to a more stable spectral. Each element of the array is an antipodal Vivaldi antenna. A 9-element sample of Pareto fronts is simulated by using CST Microwave Studio software. The synthesis results demonstrate the efficiency and accuracy of the method and quickly provide valuable information for array antenna designers.