基于时间反演的运动阵列远场功率合成

首先从理论上分析了时间反演技术运用于运动阵列近场功率合成的可能性及存在的难点和问题建立了基于时间反演技术的运动阵列远场功率合成数学模型。基于此模型,通过对信标信号从不同方向入射情况下的回溯信号波束指向进行仿真,证实了阵列辐射的TR信号可以实现自适应回溯并且比传统相控阵方法形成的合成波束能量更加集中;通过仿真获得单元天线设置为全向天线和有方向性天线时的合成信号主瓣波束3dB宽度,排除了由于阵列与目标点间的相对切向运动导致目标点脱离合成波束主瓣波束覆盖范围的可能性;分析了随机相位误差和波束指向误差对合成效果的影响,仿真结果表明:随机相位误差对回溯信号合成波束指向影响很小,但对信号的合成效果存在一定影响,由信号多普勒频移引起的波束指向误差对信号的自适应回溯影响很小。所得结论可为时间反演技术在远场功率合成的实际运用提供一定的理论依据。

Research on Far-Field Power Synthesis of Moving Array Based on Time Inversion Technology

Firstly, the difficulties and problems of applying time inversion technique to near field power synthesis of moving array are analyzed theoretically, and the feasibility of applying time inversion technique to far field power synthesis of moving array is also discussed. A mathematical model of far field power synthesis of moving array based on time inversion technique is established. On the basis of this model, by simulating the beam pointing of the retrospective signal when the beacon signal is incident from different directions, the TR signal radiated by the array can achieve adaptive retrospective and is more concentrated beam energy than that of the synthesized beam formed by the traditional phased array method. The 3dB width of the main lobe beam of the synthesized signal when the unit antenna is set as omnidirectional antenna and directional antenna is obtained by simulation. The possibility that the target point is separated from the coverage of the main lobe beam of the synthesized beam due to the relative tangential motion between the array and the target point is eliminated. The influence of random phase error and beam pointing error on the synthesized beam pointing of backtracking signal is analyzed. The simulation results show that the random phase error has little effect on the synthesized beam pointing of backtracking signal, but has a certain of effect on the synthesized signal. The beam pointing error caused by Doppler shift of signal has little effect on the adaptive backtracking of signal. The conclusions can provide a theoretical basis for the practical application of time inversion technology in far-field power synthesis.