WCDMA无线直放站的射频关键技术研究

【作者】 纪磊；

【导师】 谢银芳； 陈抗生；

【作者基本信息】 浙江大学 ， 物理电子学， 2006， 硕士

【摘要】 直放站作为移动网络覆盖的重要补充已经在第二代移动通信系统中得到了广泛的应用,它在有效增强网络覆盖面积和覆盖强度的同时降低了运营商的网络建设成本。作为一种射频透明放大设备,直放站的核心技术在于射频链路部分,射频链路直接决定了直放站的指标和成本。本文重点研究了在该频段上直放站的射频链路机构和重要部件的设计方法,主要包括以下的内容: 首先,在比较现有无线选带直放站设计方案的基础上,提出了将二次变频滤波用于无线选带直放站的方案。这种方案的优点是,成本较低,且能有效抑制镜像频率噪声。 其次,将通常在功率放大模块中采用的平衡放大结构应用于LNA的设计。这种结构有利抑制回波损耗,与天馈间的匹配更加良好。另外还设计了一种符合二次变频结构要求的单环双输出锁相频率合成器,仿真分析了电荷泵、环路损耗、环路带宽等环路参数的选择对环路的影响。 最后,讨论了耦合微带线带通滤波器的设计理论,设计了一种长度较短而加工精度要求较低的梯形耦合微带线带通滤波器,并提出了一种对微带滤波器进行“过校正逼近式”设计的方法和设计流程。更多还原

【Abstract】 As a important complementary equipment, Repeaters have been widely used in 2G mobile communication system. Repeater can enlarge the area of mobile network usefully and reduce the cost of building network. As a RF transparent amplifier, its core technology is RF part, RF part determined the performance and cost of entire Repeater. This paper is researched about framework of RF part and several important components for WCDMA Repeater. This paper mainly concern about:Firstly, discussed the framework of wireless Repeater, which is used by company nowadays. And put forward a new twice frequency conversion framework. This framework can usefully restrain mirror noise and cost less.Secondly, researched the balance amplify framework used in design LNA for reduce the import end echo when Repeater work in low signal condition. Then discuss the theory of PLL and synthesizer, and design a synthesizer for used in the twice frequency conversion framework Repeater. Also analyzed the effect for changing the parameters of loop.Lastly, discussed the theory of designing coupling line filter. Created a new ladder framework coupling line filter, which is shorter and require less process precision than parallel coupling line filter. Base on the computer emulator’s characteristic, this paper put forward a new method and flow to design coupling line filter.更多还原