W波段低噪声接收技术研究

【作者】 李科；

【导师】 张永鸿；

【作者基本信息】 电子科技大学 ， 电磁场与微波技术， 2010， 硕士

【摘要】 接收机前端是微波、毫米波雷达系统中至关重要的部分。在雷达接收系统中,超外差接收机已经得到广泛应用。本文主要对毫米波低噪声集成接收机前端的理论和设计进行研究,以完成某W波段接收机前端项目。基于超外差接收机理论,本文采用二次下变频方案,利用ADS以及HFSS仿真软件进行设计,借助混合集成方式研究W波段低噪声接收机前端。从理论的分析到电路的设计,软件的仿真及最后的成品,研制出了矩形波导E面滤波器、W波段二次谐波混频器、微波下变频模块、电源控制模块,而SPST、SPDT、W波段低噪声放大器则是通过外购。在W波段二次谐波混频器研究中,深入地分析了传统微带结构的不足,结合前人经验提出了一种新型微带结构,其变频损耗最小为8.7dB,超过国内报道的同类W波段二次谐波混频器指标,从而减小了接收机前端噪声系数。研制的三腔W波段矩形波导E面滤波器通带最大插损为1.1dB,偏离中心频率-5GHz处抑制度大于30dB,五腔W波段矩形波导E面滤波器通带最大插损为1.7dB,偏离中心频率-5GHz处抑制度为63dB;四腔U波段矩形波导E面滤波器通带最大插损为0.7dB,在偏离中心频率±5.76GHz处衰减大于60dB。微波变频模块将毫米波下变频信号再次下变频到60MHz输出,增益为30±1dB,噪声系数为2.1dB。最后总结了所做的工作,并针对不足之处给出了一些改进措施及日后研究中需要注意的问题,为以后进行W波段接收机前端的研制提供了有益的经验。更多还原

【Abstract】 Receiver front-end plays a critical role in microwave and millimeter wave radar system, and superheterodyne receiver is widely used in modern radar systems. The dissertation studies the theory and the design of the millimeter receiver front-end to meet the requirements of a project.According to the theory of superheterodyne receiver, a front-end is designed with double down-conversion based on hybrid integrated circuit. The simulation software ADS and HFSS are applied to assist design. Some components, including W-band rectangular waveguide filters, W band sub-harmonic mixers, microwave down-conversion modules and power source control module, are performed by theory studying, circuit designing and software simulation. Through deeply researching the topology of W-band sub-harmonic mixer, the shortage of traditional mixer structure is found, and a novel structure is proposed. The experiment result indicated that the minimum conversion loss of the mixer is 8.7dB, which is the best result in domestic W-band sub-harmonic mixer, and it is important in improving receiver noise figure. The three-order W-band rectangular waveguide filter which applied on receiver has a maximum insert loss of 1.2dB, a suppression of more than 30dB at an offset of -5GHz from center frequency, while the five-order W-band rectangular waveguide filter which applied on transmitter has a maximum insert loss of 1.7dB, a suppression of 63dB at an offset of -5GHz from center frequency. At the same time the four-order U-band rectangular waveguide filter has a maximum insert loss of 0.7dB, a suppression of more than 40dB at an offset of±5.76GHz from the center frequency. Microwave down-conversion modules convert down-conversion signal of millimeter wave to 60MHz and have a gain of 30±1dB with a noise figure of 2.1dB.Finally, it gives some improvement advice and easily ignored points, which can provide important roles for later research on it.更多还原