Study on direct digital frequency synthesizer technology based on piecewise pperation 基于分段運算的直接頻率合成技術研究
At first , this paper described the basic structure , working principle , sources of spurious signals and characteristics of output spectrum , of direct digital frequency synthesizer ( dds ) 首先分析直接數字頻率合成器( dds )的基本結構、工作原理、雜散來源、輸出頻譜特性。
Direct digital frequency synthesizer ( dds ) is an apparatus to generate wave on the required frequency . it provides high frequency resolution , rapid frequency transforma - tion and other superiority 直接數字頻率合成器是現代頻率合成的主要工具,它有頻率分辨率高,頻率轉化快等眾多優點。
Then according to the emphasis of the design , went deeply into the theory of pll frequency synthesizers widely used , described pll ’ s working principle , structure and several types in detail , and made research and analysis of pll frequency synthesizers ’ phase noise , including the effect of the active loop filter on the phase noise , and give some methods to make improvement as well , such as changing loop filter form , reducing divide number , and increase phase detector frequency , etc . then paper introduced the principle character and phase noise analysis of direct digital frequency synthesizer ( dds ) and injection phase lock circuit , which are also important circuits in the design 論文首先對幾十年頻率合成器的發展進行概述,而后針對本次設計的重點,對應用較為廣泛的鎖相頻率合成理論進行了深入的探討,詳細介紹了鎖相環的工作原理、組成結構和鎖相類型,并對鎖相頻率合成器的相噪特性進行了研究分析,包括有源環路濾波器對于相噪的影響,提出了改善相位噪聲的幾點措施:改善環路形式、降低分頻數、增大鑒相頻率等。接著介紹了直接數字頻率合成器( dds )和注入鎖相電路的原理特點以及相噪分析,它們也是本次設計的重要電路。
The direct digital frequency synthesizer is a kind of fully digitized frequency synthesizer , which consists of the phase accumulator , the sine look - up table , the digital to analog converter and the low band filter . it is of high frequency resolution , fast frequency switching speed , low phase noise , the ability to switch frequencies while maintaining constant phase , and the ability to producing arbitrary waveforms 直接數字頻率合成器是一種全數字化的頻率合成器,由相位累加器、波形rom 、 d a轉換器和低通濾波器構成, dds技術具有頻率分辨率高、頻率切換速度快、頻率切換時相位連續、輸出相位噪聲低和可以產生任意波形等優點。
The subject derives from electronic equipment bureau of electronic information industry of department of general equipment of china . the subject researches dds ( direct digital frequency synthesizer ) signal source of the frequency agile signal generator . it plays a good role in the important pre - research project that is the test technology of tactics anti - jamming for communication transceiver synthesis 本課題是總裝備部電子信息部電子裝備局下達的預研項目? ? 《戰術抗干擾通信電臺綜合測試技術》中的信號源部分(捷變頻信號發生器中的dds信號源部分) 。
The primary work in this dissertation : 1 . based on the analysis of direct digital synthesis ( dds ) , this dissertation compares the differences and similarities between direct digital waveform synthesizer ( ddws ) and direct digital frequency synthesizer ( ddfs ) . a dds system is presented , and the theoretical analysis and practical implementation of the system is discussed in details 本文所作的主要工作如下: 1 .全面分析了直接數字合成( dds )技術的工作原理,對比了直接數字波形合成( ddws )及直接數字頻率合成( ddfs )兩種數字波形產生方法,并就其理論設計和工程實踐問題進行討論。