The new generation radio telescopes, such as the Square Kilometre Array (SKA) currently under construction, will use aperture array, technology for the low frequency regime. For SKA2, the second phase scheduled after the realization of SKA1, aperture array technology is proposed up to 1.4 GHz. The antenna element count, as well as the signal processing cost, of such a system will be high. In this paper we analyze an option to reduce the number of antenna elements by making the array sparse. To reduce the signal processing cost Fast Fourier Transform Beamforming is proposed and it performance is compared to traditional beamforming. To guide the system design a Figure of Merit for the performance cost ratio is proposed and evaluated for various levels of sparsity of the antenna array. It is concluded that, for equal front-end and back-end costs, a sparse system is only marginally better than a dense system. Only when signal processing cost is significantly lower than the front-end hardware, a sparse system can be competitive.

中文翻译：

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扩大视野：AAMID SKA 射电望远镜站台设计

新一代射电望远镜，例如目前正在建设的平方公里阵列（SKA），将使用孔径阵列技术，用于低频区域。对于SKA2，在SKA1实现后计划的第二阶段，提出了高达1.4 GHz的孔径阵列技术。这种系统的天线元件数量以及信号处理成本将很高。在本文中，我们分析了一种通过使阵列稀疏来减少天线单元数量的选项。为了降低信号处理成本，提出了快速傅立叶变换波束成形，并将其性能与传统波束成形进行比较。为了指导系统设计，针对天线阵列的各种稀疏程度提出并评估了性能成本比的品质因数。得出的结论是，对于相等的前端和后端成本，稀疏系统仅略好于密集系统。只有当信号处理成本明显低于前端硬件时，稀疏系统才能具有竞争力。