摘要
针对短波脉冲雷达接收机高灵敏度和高信噪比的性能要求,在射频前端设计了一个提高接收机干扰抑制力的预选滤波器,给出了基于电调谐变容二极管的二级LC串联谐振实现滤波的设计方案,详细阐述了设计原理及方法,讨论了变容二极管温漂对滤波器特性的影响,提出一种滤波器自校解决温漂的新方法。测试结果表明,该滤波器系统实现了频率跟踪,可工作在1MHz～30MHz,插入损耗小于2.3dB,对带外干扰抑制能力可达29dB,提高了接收机灵敏度及信噪比,在电离层扰动探测中得到了很好的应用。
For the SW pulse radar receiver requires by high sensitivity and high signal-to-noise ratio, a pre-selected filter is designed in the RF front-end, which can improve interference rejection of receiver, a design approach of secondary LC series resonance realizing filtering based on the electrical tuning varactor is proposed. In this paper, the design principle and method are described in detail, then the influence of varactor temperature-drift on the filter characteristics is discussed, and put forward a plan of filter self-correcting. The test results show that the filter can realize frequency tracking and work on between 1 MHz to 30 MHz, with low insertion loss of 2.3 dB, the ability to suppress out-of-band interference can reach 29 dB, and the sensitivity and signalto-noise ratio of the receiver is improved greatly, which has got a good application in ionospheric disturbances detection.
出处
《微型机与应用》
2013年第7期49-52,57,共5页
Microcomputer & Its Applications
基金
国家自然科学基金仪器专项(41127003)
湖北省自然科学基金重点项目(2010CDA062)
国家科技基础性专项重点项目(2008FY120100)子课题
关键词
接收机
预选滤波器
变容二极管
自校
receiver
preselected filter
varactor
self-correcting
