相控阵馈源MVDR波束合成器缓解RFI仿真

相控阵馈源(Phased array feeds, PAFs)接收机作为下一代微波接收机, 为大口径射电天文望远镜的射电干扰(Radio Frequency Interference, RFI)缓解工作带来了新的解决方法. PAFs接收机对射电望远镜焦平面的电磁波进行空域采样, 返回时域阵列信号, 使用最小方差无失真响应(Minimum Variance Distortionless Response, MVDR)波束合成器可以自适应地识别RFI的方向, 同时抑制RFI在输出信号中的功率, 从而达到提升射电望远镜灵敏度的效果. 仿真结果表明MVDR波束合成器对有源高能量的射电干扰有很强的识别能力和一定程度的缓解能力, 同时, 该波束合成器对各阵元信道中加性噪声累积引起的无源干扰有很强的抑制能力, 因此, PAFs接收机的MVDR波束合成器可以增强日益复杂电磁波环境下射电望远镜的抗干扰能力.

Simulation of Phased Array Feeds MVDR Beamformer to Mitigate RFI

The phased array feeds (PAFs) receiver is a next-generation microwave receiver that provides a new solution to reduce Radio Frequency Interference (RFI) for large-aperture radio astronomy telescopes. The PAFs receiver samples the electromagnetic wave in the focal plane of the radio telescope in spatial domain and returns the time-domain array signal. The use of Minimum Variance Distortionless Response (MVDR) beamformer allows for adaptive identification of the orientation of RFI while suppressing the power of RFI in the output signal, thereby enhancing the sensitivity of the radio telescope. The simulation results show that the MVDR beamformer has a strong ability to identify and mitigate active high-energy radio interference. Meanwhile, the beamformer has a strong ability to mitigate passive interference caused by the accumulation of additive noise in each array element channel. Therefore, the MVDR beamformer for PAFs receiver enhances the anti-interference capability of the radio telescope in the increasingly complex electromagnetic wave environment.