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。
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.
引文
[1] 3GPP TS 25.106, UTRA Repeater wireless transmission and reception, edition five, 2003-09
[2] Analog Devices Inc, PLL Frequency Synthesizer ADF4106, ADI Datasheet, 2005
[3] Agilent Technologies Inc, Agilent ATF-54143 Low Noise Enhancement Mode Pseudomorphic HEMT in a Surface Mount Plastic Package, ATI Datasheet, 2003
[4] Reinhold Ludwig, Pavel Bretchko, RF Circuit Design: Theory and Applications, 北京,电子工业出版社,2002
[5] Ulrich L. Rohde, David P. Newkirk, RF/Microwave Circuit Design for Wireless Applications,北京,电子工业出版社,2004
[6] 陈抗生,《射频与微波电路设计》讲义,杭州,浙江大学信电系,2002
[7] 陈邦媛,射频通信电路,北京,科学出版社,2002
[8] Dean Banerjee,"PLL Perfomance, Simulation, and Design", Second Edition, 2001
[9] 仇善忠,张冠百,锁相与频率合成技术,北京,电子工业出版社,1986
[10] 张厥盛、郑继禹、万心平,锁相技术,西安,西安电子科技大学出版社,1994
[11] Cotter W. Sayre, Complete WirelessDesign, 北京,人民邮电出版社, 2004
[12] Analog Device Inc, Phase-Locked Loops For High-Frequency Receivers and Transmitters, 1999
[13] 王家礼,微波电路CAA与CAD,西安,西安电子科技大学出版社,2003
[14] 赫崇骏,韩永宁,袁乃昌,微波电路,北京,国防科技大学出版社,1999
[15] 甘本祓,吴万春,现代微波滤波器的结构与设计,北京,科学出版社,1973
[16] 清华大学《微带电路》编写组,微带电路,北京,人民邮电出版社,1979
[17] JiaSheng Hong, M. J. Lancaster, Microstrip Filters for RF/Microwave Applications, John Wiley & Sons Inc, 2001
[18] Brady D, The design, fabrication and measurement of microstrip filter and coupler circuits, High Frequency Electronics, 2002 (4): 22-26
[19] 白居宪,低噪声频率合成,西安,西安交通大学出版社,1995
[20] 吴万春,集成固体微波电路,北京,国防工业出版社,1981
[21] Walid.Y, Ali-Ahmad, RF System Issues Related to CDMA Receiver Specification, RF Design, 1999
[22] Pieter L. D. Abrie, Design of RF and microwave amplifiers and oscillators, New York McGraw-Hill Book Co, 1989
[23] A. J. Ward,"A Low Noise High Intercept Point Amplifier for 1930 to 1990 MHz using the ATF-54143 PHEMT", Agilent Application Note AN 1222
[24] Andrew. Dearn, How to design RF-circuits-Oscillators, 2000 the Institution of Electrical(Engineers Print and published by the IEEE).
[25] 马小丽,2GHz WCDMA数字蜂窝移动通信网直放站技术要求介绍,电信网技术,2005(5):29-31
[26] 高健,罗华斌,直放站的原理与应用,中国无线电,2005(7):30-33
[27] 王有为,吴远江,中兴通讯的WCDMA直放站应用研究,移动通信,2005(11):109-111
[28] 刘久文,RF低噪音放大器的仿真设计方法,北京航空航天大学学报,2000(6):259-262
[29] 张士化,何子述,S波段低噪声放大器的分析与设计,现代电子技术,2005(18):75-77
[30] 曾令儒,余玉材,微带带通滤波器的设计方法,微波学报,1996(6):147-150
[31] http: //www.3gpp.org
[32] http: //www.kilomega.com
[33] http: //www.21rf.com