《电讯技术》专题资料《时间频率技术》题要（十三）

一种基于正交调制技术的宽带频率源设计（刘类骥，林巧莉） 针对传统DDS内插PLL频率合成方法的某些不足之处，提出了一种新的基于正交调制技术的频率合成方法，该方法容易实现频率源的宽带小步进输出，且电路形式简单。最后给出了一个该方法的应用实例设计，为宽带小步进频率源的设计提供了较好的思路。     

一种新颖的星载宽带频率源设计

针对应用于复杂空间环境的宽带接收机的需求,提出了一种新颖的频率源设计方案 。采用锁相环（PLL）和倍频电路实现宽带频综,采用直接数字频率合成器（DDS）实现窄带 细步进频综。给出了频率源的详细设计思路、实现方法及可靠性设计的相关内容,实测 结果表明所设计的频率源各项指标均满足要求。     

一种W频段频率步进雷达频率源的相位补偿方法

介绍了频率步进雷达信号实现距离高分辨的工作原理。针对采用步进频信号的某W频 段末制导雷达在系统调试过程中,由于频率源本振和激励源不同频点的相位差不同造成距离 像畸变的情况,分析了信号相位变化对高分辨距离像的影响,根据步进频信号距离高分辨的 原理,提出一种对各频点间相位差进行相位补偿的方法。计算机仿真结果表明 其可行性,并在试验中对该方法进行了验证。通过该方法可以不用对步进频信号各频点的相 参性过高要求,即可得到高分辨距离像,达到理想的距离分辨率,有效降低了W频段频率源 设计和调试的难度。     

一种新型的超宽带细步进频率源设计

介绍了一种利用DDS、PLL和正交调制技术实现超宽带、细步进、低杂散频率源的设计方法.与传统混频锁相相比,采用正交调制技术具有方案简洁、电路简单、输出频带宽、体积小等优点.给出了一种基于AD8349型正交调制器的超宽带频率源设计实例,该设计已在工程中得到应用,其测试结果满足工程要求.     

低成本C频段宽带变频锁相源的设计与实现

选取具有数字接口、高度集成的锁相环(PLL)电路,实现了C频段5.4～6.4 GHz带宽内输出频率数控可变、步进间隔为50 kHz的宽带集成锁相源的设计方案.按照该设计方案制作完成了具体的电路,经过实验测量,验证了该电路具有较宽的工作带宽、较高的噪声抑制度,系统整体性能良好,便于数字控制,成本较低.     

《电讯技术》专题资料《时间频率技术》题要（十六）

1.频段小步进频率综合器概述（林巧莉） 概述了L频段小步进频率综合器的工作原理，并结合工程的需要，阐述了其在调试过程中的设计要点，提出了一些抑制杂散和提升相噪指标的方法，并给出了测试结果。     

一种雷达频率源的简易设计方法

针对传统多功能雷达频率源方案复杂、体积大、成本高的缺点,提出了一种雷达频率源的简易设计方法。该方法基于高频主振分频的频率合成方案,并通过信号频率的组合设计进一步简化了电路形式,成功实现了某型雷达所需的线性调频激励源、捷变频本振源、多普勒模拟源、采样时钟等多路信号的输出,X频段信号相位噪声达-106 dBc/Hz@1 kHz和-114 dBc/Hz@10 kHz,跳频时间小于2 ??s,性能指标与采用直接频率合成实现的雷达频率源相当。     

一种性能优良的宽带放大器

本文设计出一种以ad603为核心的宽带放大器.实验表明该放大器具有结构简单、频带宽,增益高,且增益可调,agc动态范围宽、步进间隔小的特点.     

基于SOPC的DDS信号源的实现

本文介绍了直接数字频率合成(DDS)的工作原理以及基于可编程片上系统(SOPC)实现DDS信号源。设计的DDS信号源以Cyclone器件为核心,用嵌入在FPGA中的N ios软核CPU作为控制来实现频率、相位和幅度的数字预制和步进,利用FPGA的RAM位放置正弦查找表,同时利用FPGA的逻辑单元实现相位累加等其它数字逻辑功能。实现了两路相位完全正交的DDS信号源。     

C频段频率合成器设计

DDS与PLL的组合方式通常有两种，PLL内插DDS和DDS激励PLL的组合方式。本文充分利用了这两种方式的优点，实现了一种能完全覆盖C频段的宽带低相位噪声频率合成源设计。首先在理论分析的基础上给出了设计方案，然后对其可行性进行了论证，最后用实验结果证明了该方案的正确性。     

Brown＇s Blossom in Britain-China

The overall strategic relationship between U.K. and China is ＂better than ever＂, China- Britain relations have maintained good momentum, with increased high-level exchanges and the reinforcement of strategic mutual trust, with more room for growth in the future.     

Challenge and Opportunity Go Hand in Hand——What Global Economic Agitation Brings to the China's Economy?

Domino effects of the global finance agitation As the origin of the subprime crisis,US financial institutions lost USS45 billion last year,accounted for over half of the total US,EU & Japan loss.Since January 15th,Chtigroup released its financial statement of the 4th quarter,showing a net deficit of USS9.83 billion,which marked the hisoric high of its quarterly deficit.     

Sinosteel：Extraordinary Moves in Industry Chess

Among the Fortune 500 firms,more and more images from China emerge out.On the 2008 list,Sinosteel Corporation,a landmark group of China industries quietly squeezes into the candidate line.As the largest steel service ＆ trade enterprise,its sales reached at RMB 111.24 billion,with a year-on-year increase of 83.03 percent,and the profit grew by 180.03 percent.On the Sinosteel 2008 Work Meeting,the president Huang Tianwen uttered,＂In the coming year,we will work for US$20 billion sales,and look forward to getting a position in Fortune 500 firms for ourselves.＂     

Walk Through Unusual Five Years—— An Exhibitor＇s Canton Fair Course

When the 103rd Canton Fair is approaching, an old friend of Canton Fair, Li Ying from Jiangsu prov-ince recollected his past five years＇ experiences to the grand trade meeting. Each year is special, with some unforgettable memories colored by the year.     

Universal Coverage, Pinpoint Illustration and Profound Impact HTC 2008 Intermedia Recommendation and Introduction Meeting

Holding 88 percent of train media resources across China, based on "Time Cube", on the 2008 Intermedia Recommendation and Introduction Meeting on December 19, 2007, HTC announced its high-profile strategy of tour marketing and tapping the immeasurable potentials on the train. Meanwhile, HTC officially launched its brand new product Olympic Train on the meeting, providing a fabulous platform for all the brands that are prepared to do a smart marketing on the occasion of 2008 Olympic Games.     

Market presence in China strengthened Network growth and Dual-Chinese-Hub Strategy More frequet Flyer Benefit——Air China and shanhai Airlines Join Star Alliance

In the end of 2007, Air China Limited (hereinafter "Air China") and Shanghai Airlines, formally joined Star Alliance at a ceremony held in the new Terminal Three at Beijing Capital International Airport. With the addition of the two Chinese airlines, Star Alliance now has 19 member carriers operating 17,000 daily flights to 897 destinations in 160 countries.     

China''''s Stock Market Wave

The annual meeting of the World Economy Forum was held in Davos,a little town in Switzerland,on January 23rd to the 27th this year,with the theme"the Power fo Collaborative Innovation",over 2500 celebrates from ture political and cconomic circles of more than 80 countries and challengred logether to talk about the future of the global economy in 2008,A Forum for the problems and challenges that face whole world,some of the keywords which drew attention during the event were:the U.S.subprime mortgage crisis,soaring energy prices,the economic slowdown in the U.S.ermerging economic bodies,authority funds and the general unpredictable nature of the global economy.     

Trade Promotion from Neighborhood

If you are considering to trade with companies in Japan or expanding your .business to Japan, we are ready to help from the very beginning.＂ You will find this greeting at the first sight on the Chinese website of Japan External Trade Organization （JETRO）. JETRO has committed itself in delivering highly efficient and quality services to meet the demand of internal and external customs including Japanese companies, hence winning a good reputation in the international trade arena. In recent years, with its priority in advancing business cooperation in South and East Asia, JETRO has made great achievement in promoting trade between China and Japan. Therefore, China＇s Foreign Trade interviewed Mr. Yoichi Maine, Deputy Director General of JETRO BEIJING.     

Auto Parts Market Potential Coming into Surface

Looking at the increasingly fierce competition in the world auto market. global automobile manufacturing industry, taking Europe, the U.S. and Japan as representatives, is gradually forming a new type of relationship, mutual cooperation between whole vehicle and parts manufacturers. We can clearly see that auto parts manufacturers have become independent from the whole vehicle manufacturing companies, which means that the former structure of auto industry has greatly changed, and a new relationship,     

Jean-Pierre Duprieu： Willing to Be A Legate of Sino-French Business

Estaing, former French president, Valery Giscard d＇Estaing attended Sino-French Economic Seminar held in Shanghai in early April and said that the world center has shifted from the west to the east with many European and US companies entering into Asia, and China has the ability to play an important role in the world stage. Estaing, naming himself＂French Confucian＂, then said in Chinese that a cook-group includes 10 people in ancient Chinese soldier system and the cook is in charge of cooking for them. And people who belong to the same cook are actually ＂Partners＂.