Space-based solar power systems (SSPS) envision the usage of focused microwave beams to transfer power from space to ground. To supply a large amount of power and to be able to focus a microwave beam efficiently, a large infrastructure must be assembled in orbit, thus, making the implementation of SSPS an arduous task. In the history of SSPS designs, aside from economical obstacles, technical obstacles such as large ohmic losses due to long DC lines in the structure, large rotary joints to decouple beam pointing and solar power collection, heating problems from power lines converging into a single point, and complex control mechanisms, manufacture, and assembly are present. A simpler implementation using multiple foldable thin film membrane satellite modules is proposed as a feasible design, born from the advancement of thin film electronics. Its economical feasibility is achieved through the reduced weight, large surface area, and membrane’s ability to be stowed. The thin film SSPS combines advantageous properties of past designs such as a simple structure, simple control mechanism, and a distributed power collection and transfer architecture avoiding the ohmic loss and heating problems. However, due to the thin film membrane hosting both the antenna and the solar cells, competition occurs between maximum solar power collection and high efficiency power transfer capabilities. In this paper, we propose a framework to analyze the performance of the thin film SSPS solar cell-antenna integration design in terms of the wireless power transfer efficiency and fuel consumption, from which we identified the trade-offs on designing and operating the station. We used this framework to analyze three different antenna element designs in combination with three different attitude control goals, and found out that the key aspects of the antenna design are beam width, radiation efficiency, and efficient solar cell integration.

中文翻译：

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薄膜空间太阳能卫星的微波无线电力传输效率分析框架

天基太阳能系统（SSPS）设想使用聚焦微波束将电力从太空传输到地面。为了提供大量功率并能够有效地聚焦微波束，必须在轨道上组装大型基础设施，因此，SSPS的实施成为一项艰巨的任务。在SSPS设计的历史中，除了经济障碍外，技术障碍还包括结构中长直流线导致的大欧姆损耗、用于解耦光束指向和太阳能收集的大型旋转接头、电源线汇聚成单点产生的加热问题，并且存在复杂的控制机制、制造和组装。由于薄膜电子学的进步，提出了一种使用多个可折叠薄膜卫星模块的更简单的实现作为可行的设计。其经济可行性是通过减轻重量、增大表面积和膜的存放能力来实现的。薄膜SSPS结合了过去设计的优势特性，例如简单的结构、简单的控制机制以及分布式功率收集和传输架构，避免了欧姆损耗和发热问题。然而，由于薄膜薄膜同时容纳天线和太阳能电池，最大太阳能收集和高效电力传输能力之间会发生竞争。在本文中，我们提出了一个框架来分析薄膜SSPS太阳能电池-天线集成设计在无线功率传输效率和燃料消耗方面的性能，从中我们确定了设计和运营该站的权衡。我们使用该框架结合三种不同的姿态控制目标分析了三种不同的天线元件设计，发现天线设计的关键方面是波束宽度、辐射效率和高效的太阳能电池集成。