【摘要】 高温超导材料的微波表面电阻比铜等金属小将近3个数量级,所以自从高温超导材料发现以来,人们就开始了高温超导微波滤波器的研究,并研制出了各种各样具有低损耗、高选择性、优异的带内群时延特性等性能优异的高温超导滤波器.与此同时,高温超导滤波器的应用研究也取得长足进步.目前,由高温超导滤波器、微型斯特林制冷机及半导体低噪声放大器等组成的高温超导微波前端子系统已经在移动通信、雷达、深空探测和卫星通信等多个领域获得应用并取得了显著的经济和社会效益.近年来,高温超导滤波器的研究也在不断地向新的方向拓展,在大功率承载能力、多通道器件、可调频率滤波器以及全超导接收机等领域取得显著进展.本文对高温超导滤波器的研究现状和应用进展进行总结,并对高温超导滤波器及微波应用的研究发展趋势进行展望.更多还原

【Abstract】 Microwave filters are essential elements in many areas of RF/microwave engineering. The crowded frequency spectrum has put forward higher requirements on channel filters. Not only very high close-to-band rejections are required to prevent interference to or from closely neighboring channels, but also very low insertion loss is required to reduce system noise figure. Some RF/microwave system require in-band group-delay and amplitude flatness to minimize signal degradation even further. Surface resistance of high temperature superconducting(HTS) material is about 1000 times less than the best conventional metals such as copper and silver at microwave frequency. So a significant effort has been put into the research and realization of high performance microwave HTS filters since the discovery of HTS materials. HTS microwave filters with remarkably high performance have been constructed in the past 30 years. For example, by selecting appropriate resonators with high quality factors and employing well-designed coupling structures with week coupling coefficients, some HTS filters can have fractional band width(FBW) blow 0.1% with very high selectivity. The insertion loss of some HTS filters can be as low as 0.05 d B. With above excellent performance, HTS filters can not only eliminate unwanted interference but also minimize noise figure of the microwave system. HTS filters and their front-end subsystems have also been successfully applied to many fields and brought multiple economic returns and social benefit. It is reported that HTS receiver front-end subsystem, which integrate with narrow-band highly selective HTS filters and low noise amplifiers(LNA) in a cryocooler, has been employed in more than 10000 base stations in America. According to the promotion materials, the ultra-low-loss and high sensitivity of the HTS receiver can translate into 10%–15% or more increased base station coverage area and data throughput. In some cases carriers could add 8% or more usable resource blocks and capacity due to the high selectivity of the HTS receiver, valued at hundreds of millions of dollars. Design technology of HTS filters has been developed rapidly at an incredible speed. In recent years, many efforts have concentrated on novel HTS filter design technologies, including those in high power handling capability filters, multiplexer or multiband filters and frequency tunable filters. Some research groups are trying to develop all-HTS integrated microwave front-end receivers, which integrate HTS filter, oscillators, mixers and antenna into a whole chip. The all-HTS integrated front-end receiver could make the system compact, efficient, and be able to exploit the full potential of the superconductive components. In this paper, the research status, trend of development and application progress about HTS filters are reviewed. The best performances of HTS filters ever reached in specifications such as insertion loss, FBW, out of band rejection, skirt slope and in band group delay are firstly reviewed. Then the remarkable progress in the most recent years which stand for the research trends of HTS filter technology is presented in detail. At last the application of HTS filters and their front-end subsystems to mobile communications, space or satellite communication technology, radar detective system, deep space detection and radio astronomy is also reviewed.更多还原