【作者】 林杰；

【导师】 谭晓衡；

【作者基本信息】 重庆大学 ， 通信与信息系统， 2010， 硕士

【摘要】 无线通信的快速发展使得频率资源日趋紧缺。射频(RF, Radio Frequency)前端在无线通信收发机中的特殊作用,使它成为了国内外无线通信领域的研究重点和难点。本文根据项目“多功能通用信号源及接收装置”的无线QPSK调制传输系统对射频前端的要求,对2.4GHz工业、科学以及医疗(ISM,Industrial Scientific Medical)频段接收机的射频前端及其主要模块进行了深入研究,并给出了主要模块的设计方法。本文的主要工作及创新点在于:首先,给出了射频接收机的性能参数,分析并比较了常用接收机的结构。根据项目实际的设计需要,给出了2.4GHz无线通信系统所采用的接收机前端结构,分析了所采用的接收机结构的性能。其次,重点研究了射频滤波器,分析了射频微带带通滤波器的设计理论以及设计方法,并在此基础上仿真和分析了几种常见的微带带通滤波器。创新地设计了一个中心频率为2.45GHz的发夹型阶梯阻抗谐振器(SIR,Stepped Impedance Resonators)微带小型化带通滤波器,并进行了仿真优化。最后制作了该射频微带带通滤波器的硬件电路,经过测试,该滤波器不仅与理论仿真结果相吻合,而且性能理想、尺寸也很小。最后,利用软件设计了基于晶体管的低噪声放大器(LNA, Low Noise Amplifier)和基于变频二极管的无源单平衡混频器,并进行了仿真;根据系统设计要求,对仿真电路和性能参数进行了反复优化,设计出了满足项目需求的2.4GHz无线通信系统的接收机射频前端模块。然后,基于LNA和混频器的单片微波集成电路(MMIC, Monolithic Microwave Integrated Circuits)芯片,制作了低噪声放大器和混频器的硬件电路,并进行了实际电路的调试,对设计的各部分电路进行了性能测试和数据分析,满足项目需要,验证了各个模块设计方案的可行性。更多还原

【Abstract】 The rapid development of wireless communication makes the frequency resource becoming scarcer and scarcer. The special function of RF front-end in the wireless communication transceiver makes it be the key and difficult in the research of wireless communication domain all around the world. According to the requirement of wireless QPSK modulation transmission system of the project“multifunctional and universal signal sources, this thesis studies and discusses the designing method of the RF front-end of the receiver as well as its main modules at 2.4GHz ISM band. Main works and innovation of this thesis include:Firstly, this thesis presents the performance parameters of RF receiver, and analyses and compares the usual structures of RF receiver. Then, according to the actual requirements of the project, this thesis presents the adoptive RF receiver structure of 2.4GHz wireless communication system, and analyses the performance parameters of this structure.Secondly, it is emphasized on the RF filters. Based on the analyzing of the designing theory and method for the RF micostrip band-pass filters, several usual micostrip band-pass filters are simulated and analyzed. Then, a compact hairpin microstrip bandpass filter centered at 2.45GHz is designed, simulated and optimized innovatively based on SIR, at last, manufactured the hardware circuit. The measurement result demonstrates that it is in agreement with the simulation result, and the designed filter is of small dimension with ideal performance.Finally, a LNA based on transistor and a passive single balanced mixer based on frequency diode is designed and simulated using software. According to system requirements, this thesis makes optimization of simulation to the modules circuits and analyzes the performance parameters again and again. Finally, the modules of a 2.4GHz communication system RF front-end which can satisfy the requirement of the project are designed. At last, the hardware circuits of LNA and mixer based on MMIC are manufactured, measured and debugged, and the performance measurement results and the results analysis satisfies the requirement of the project and validates the feasibility of each designing module.更多还原