65米射电望远镜中频传输分配系统的研制  

Development of an IF-Signal Transmission and Distribution System for the 65m Telescope of the SAO

作　　者：袁瑾[1] 苟伟[1] 赵融冰[1] 李斌[1] 

机构地区：[1]中国科学院上海天文台,上海200030

出　　处：《天文研究与技术》2015年第3期262-269,共8页Astronomical Research & Technology

基　　金：国家自然科学基金(11473060)资助

摘　　要：设计和实现了65m射电望远镜中频传输分配系统，频率范围0．1～2．5GHz，通道数6路，0～30dB衰减本地和远程可调，链路增益、端口驻波比、分配输出隔离度、通道一致性等指标满足要求，给数字终端提供了良好的中频输入信号。经过系统验证，该中频传输分配系统整体性能优良。可以很好地满足射电观测的需求。The 65m radio telescope of the Shanghai Astronomical Observatory （SAO） is an advanced radio-telescope system which has a large aperture, a high frequency limit for detection, multiple frequency bands for observation, and an antenna movable to any sky direction. Because of the site of the telescope, the distances from its receivers to its digital terminals are nearly 500m. It is thus an issue to accurately transmit radio signals received by the telescope antenna. In radio astronomy it is a common practice to first convert received radio signals to proper Intermediate-Frequency （IF） signals, and then transmit the IF signals through coaxial cables to a terminal room, where the IF signals are distributed to multiple terminals and monitoring equipments. The distribution also requires highly consistent division of single-channel signals into muhi- channel signals. Meanwhile, the needed powers of signals input to different terminals are different; it will be convenient to correct for attenuations of signals input to various terminals, respectively. In this paper, we present the design and implementation of an IF-signal transmission and distribution system for the 65m radio telescope, which has a frequency range for observation of O. 1GHz to 2. 5GHz and a channel number of 6. The signal-attenuation correction range of the system is l dB to 30dB, and the correction can be controlled on-site or remotely. The specifications of the system, including link gains, VSWR, isolation levels, and consistency levels in distributed outputs can meet the demands. These enable the system to provide high-quality IF signals usable as inputs of the digital terminals. We have carried out tests and verified the high-level performance of the system. Overall, the system can meet the needs of radio-astronomy observations of the SAO.

关 键 词：射电望远镜 中频传输链路 宽带均衡 中频分配 衰减控制 

分 类 号：P111.44[天文地球—天文学]