KMS of Xinjiang Astronomical Observatory, CAS
| 高灵敏度超宽带接收机研制技术 | |
| Alternative Title | Development of Broadband Receiver for Radio Astronomy |
陈卯蒸
| |
| Subtype | 博士 |
| Thesis Advisor | 王娜 ; 郑兴武 |
| 2016 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 天文技术与方法 |
| Keyword | 接收机 宽带 馈源 噪声温度 Mmic |
| Abstract | 天文研究的快速发展对射电望远镜提出了更高的要求——更宽的带宽、高灵敏度和大视场观测能力。超宽带接收机将是进一步提高射电望远镜灵敏度的关键因素。国际上的射电望远镜都在不断更新接收机系统，以实现更宽的频率覆盖提升探测能力。超宽带接收机技术也成为射电天文技术研究的重要内容之一。 新疆天文台南山25米射电望远镜在20多年的运行中，接收机也在不断升级改造。其中1.3cm波段接收机已经不能适应天文研究课题的需求，迫切需要研制一台新的噪声温度更低的双极化制冷接收机。本论文通过1.3cm双极化制冷接收机的研制，研究探讨了高灵敏度的超外差式制冷接收机设计方法、杜瓦和低温结构的设计技术、接收机整体集成设计与测试技术等。本论文以微波噪声理论为基础，采用微波级联网络分析和设计方法，仿真计算接收机参数指标，并进行优化设计。为达到极低的噪声温度，论文采用了独特的设计，对馈源和极化器进行全制冷到15K。在杜瓦设计工艺上，采用铝合金材料的长方体结构，既保证了杜瓦的真空性能，又具有良好的可维护性。基于CATIA三维机械设计软件精密设计了诸多的无氧铜结构部件，保障了各个低温器件和冷头之间的良好热传导。1.3cm制冷接收机研制完成后实测噪声温度好于16K，达到国际上同类接收机先进水平。 新疆天文台正在推动奇台110米射电望远镜（QTT）的建设，目标是建成世界一流的观测研究平台，而研制并装备超宽带接收机是实现这一目标的必要条件。QTT频率覆盖范围从150MHz到115GHz，本论文针对特定波段以超宽带馈源和低噪声放大器为入手点研究超宽带接收机前沿技术。本论文设计了L波段（1 ~ 2GHz）、30cm波段（0.6 ~ 4GHz）和7mm波段（30 ~ 50GHz）的超宽带馈源和极化器。论文首先建立了HFSS波导器件模型，优化通带内的S参数，通过试制样件实测，验证仿真结果与实测值基本相符。论文还研究了基于MMIC的低噪声放大器技术，建立HEMT低温参数模型，在ADS中设计了12 ~ 36GHz和30 ~ 50GHz波段的低噪声放大器电路原理图和电路版图，流片试制了放大器芯片，并在探针台上在片测试了S参数。实测S参数与仿真值大体上一致。这些研究结果表明本论文的研究方法和技术路线可行，为后续更深入的研究和优化设计积累了经验，也为QTT实现接收机技术方案奠定了基础。 |
| Other Abstract | Ground-breaking radio astronomy research in the future will require unprecedented levels of sensitivity while mapping large regions of space with much greater efficiency than is achieved with current telescopes. This requires new instrumentation with the greatest achievable sensitivity, broad frequency band, and field of view. Ultra broadband receiver will improve the sensitivity of radio telescope. The receivers of worldwide radio telescopes are upgrading to cover more wide frequency range. And the broadband receiver technology has become more and more important. The receivers of the Nanshan 25-mradio telescope of Xinjiang Astronomical Observatory are also constantly updated. A new 1.3cm band dual polarization cryogenic receiver was urgent to be carried out. In this paper we study the design of high sensitive heterodyne cooled receiver, the fabrication of the Dewar and the cryogenic parts, the receiver integrated design and testing technology through the development of 1.3cm cooled receiver. Based on the microwave noise theory, we calculate and simulate the performance of the receiver by the method of microwave cascade network analysis. The feed and the polarizer also are cooled down to 15K to achieve the lowest noise temperature. The design of the cubic aluminous Dewar improves the reliability and maintainability with no compromise in vacuum performance. Many copper components are designed in CATIA, and fabricated precisely. The noise temperature of 1.3cm receiver is better than that 16K; this receiver is one of the most sensitive of the world. The general goal of the Qitai 110-m Radio Telescope (QTT)project is to build a 100-m aperture omni-directional rotational radio telescope, which has superior performance, steady working state, high-efficient observation and international advanced parameters Its scientific goal is to promote the development of the research level of Chinese and international radio astronomy. The frequency range of QTT is from 150MHz to 115GHz.We study the ultra-broad band feed and low noise amplifier to face the requirement of QTT. This paper design the L band (1 ~ 2 GHz), 30cm band (0.6 ~ 4GHz) and 7mm band (30 ~ 50 GHz) ultra wideband feed and polarizer. Is firstly established the HFSS waveguide device model, optimization pass band s parameters, through prototype measurement and simulation results and the measured value is basically consistent. We also study the based on MMIC low noise amplifier technology, the establishment of HEMT cryogenic parameters model, in the ads in the design of the 12 ~ 36GHz and 30 ~ 50 GHz band low noise amplifier circuit schematic diagram and PCB layout, fabricate the chips by MCP, and measure the S parameters on the probe station. The measured S parameters are in general agreement with the simulated values. These research results show that the research methods and technical routes are feasible, accumulate experience for the further research and optimization. |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/1712 |
| Collection | 研究生学位论文 射电天文研究室 |
| Affiliation | 中国科学院新疆天文台 |
| Recommended Citation GB/T 7714 | 陈卯蒸. 高灵敏度超宽带接收机研制技术[D]. 北京. 中国科学院大学,2016. |
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| 陈卯蒸-学位论文.pdf（6753KB） | 学位论文 | 暂不开放 | CC BY-NC-SA | Application Full Text | ||
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