新一代多波束接收系统的科学目标与概念设计

大视场、高灵敏度、高分辨、宽带信号接收以及多偏振成份接收等,是银河系毫米波分子谱线巡天不断追求的目标.从一氧化碳(CO)多谱线巡天的最新进展出发,归纳了未来银河系大尺度分子巡天可着重瞄准的几个前沿科学目标,包括广域弱发射区的探查、分子云内部结构的多探针成像以及银河系大尺度气体结构与物质循环调查等.介绍3毫米波段新一代多波束接收系统的一套概念设计.结合最新的技术预研,给出实现该方案的技术要点.新一代多波束接收系统的概念设计瞄准了100波束的接收规模,众多谱线以及双偏振成份的接收能力.在继承边带分离混频原理的基础上,基于新近发展的超导混频器集成电路,实现双偏振接收的新模式.在多谱线信号接收的基础上扩大每个信号边带至8 GHz从而同时接收众多谱线.参照已有的技术基础和近期预研的进展,本概念设计方案完全可以实现.与现有毫米波多波束接收设备相比,新一代毫米波多波束接收系统的综合接收能力预计将提升89–178倍.该设计将为毫米波多波束接收能力再次实现变革性的飞跃提供可能.

Science Cases and the Conceptual Design for a New-generation Multi-beam Receiving System

Wide field, high sensitivity, high resolution, wide bandwidth, and polarization components are constantly pursued by CO molecular line surveys at millimeter wavelengths. Several key science cases that could be focused on by future large-scale molecular surveys have been identified upon the current progress of molecular surveys. A conceptual design for the new-generation multi-beam receiver system is proposed. Combined with the latest technical progress, the key technical solutions to realize the scheme are explained. The new design aims at a receiving scale of 100 beams. Following the newly developed hybrid planar integration technology, a new dual polarization receiving function is realized while inheriting the sideband separation mixing mode. On the basis of multi-line receiving configuration, each receiving sideband is expanded to 8 GHz. Judged from the existing technologies and the newest progress, this conceptual design scheme is fully achievable. Compared with the existing millimeter wave multi-beam receiving equipment, the comprehensive receiving capacity of the new generation millimeter wave multi-beam receiving system is estimated to increase by a factor of 89--178. This design is expected to bring another evolutionary progress for millimeter wave multi-beam receiving capability.