dds direct digital synthesis 中文意思是什麼
dds direct digital synthesis
解釋
直接數字合成-
This paper illuminates theory, structure, spectrum distribution, merits and defects, especially spurs of direct digital synthesis ( dds ), and it then introduces phase locked loop ( pll ) theory
對dds的結構、優缺點、頻譜分佈，特別是雜散性能進行了詳細的闡述。接著，又介紹了鎖相環（ pll ）的原理。 -
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 circulation function therapeutic instrument of brain based on direct digital synthesis ( dds ) technology uses the domestic newest scientific findings and others in foreign countries. adopting the dds technology directly, it produces the safe, valid treatment. through pasting heart electric electrode on body surface, it introduces electric current to cerebral fastigial nucleus ( fn ) without damage in order to improve the state of brain blood supply and nerve conducted and something of lacking proper care to lose the symptom of coordinating with a net, increase cerebral blood flow, reduce downright bad neuron figure, district of penumbra, lighten brain perinemotoma
基於直接數字頻率合成技術的智能腦電治療儀應用國內國際上最新科研成果，採用直接數字頻率合成技術，實現安全、有效的治療，通過粘貼于體表的電極，無創引入小腦頂核，從而改善腦供血狀態和神經傳導失調失絡癥狀，增加大腦血流量，減少半影區壞死神經元數目，減輕腦水腫，最終達到改善腦循環功能的作用。 -
Considering the fact that the analog system is not so good as the digital system on the respect of variation of bandwidths and on the respect of switch between different bandwidths. this paper proposes to adopt the dds ( direct digital synthesis ) technique that produces chirp signals of different bandwidths to improve the situation of losing tracks for the ocean satellite altitude indicator in measuring coarse surfaces
現在的雷達基本上採用模擬系統產生線性調頻信號，由於模擬系統在帶寬變化方面和不同帶寬間切換方面不如數字系統，本文採用dds （ directdigitalsynthesis ）技術產生不同帶寬的線性調頻信號以改善海洋衛星高度計在測量粗糙表面時存在的失鎖現象。 -
With the development of digital technology, getting pulse compression signals with direct digital synthesis has been in general use these days. it is widely used to generate pulse compression signal using dds method
隨著現代數字技術的發展，直接數字波形合成（ dds ）的方式獲得脈沖壓縮信號已為現代雷達普遍採用。 -
Secondly, the principle and direct digital frequency synthesis ( dds ) is analyzed deeply. thirdly, the whole system is designed according to the design flow
其次，對實現原理和在設計中需要用到的直接數字頻率合成技術進行了深入的分析。 -
Direct digital frequency synthesis ( dds ) is a new frequency synthesizing technique which is developed rapidly in recent years
直接數字頻率合成（ dds ）是近年來得到迅速發展的一種新興頻率合成技術，它具有頻率精度高、切換速度快、相位連續等優點。 -
Dds ( direct digital frequency synthesis ) can just solve this problem, yet the output has an upper bound and high wideband spurs
Dds （直接數字頻率合成）的出現恰好可以彌補這一缺陷，但是它輸出頻率上限太低，寬帶雜散大。 -
This paper goes on with analysis of the phased array radar calibration theory and compare of different schemes, then the best is adopted. 2 mhz digital circuit mainly composed of dds ( direct digital synthesis ) chip, which carries out the shift of the phase and the limit of the amplitude, has been designed and debugged successfully. it is used to substitute for the conventional phased shift circuit and amplitude limiting circuit which work at the radio frequency, so the all - digital transmit channel of phased shift array radar is achieved
本論文研究的重點是：針對傳統相控陣雷達系統收發（ t r ）組件中的移相和限幅功能均在射頻段完成，大膽利用直接數字合成（ dds ）晶元組成頻率在2mhz左右的數字電路代替傳統相控陣雷達在射頻段進行移相和限幅的電路，從而組成全數字發射通道，使對相位和幅度的控制和調試更方便快捷，並設計具體的電路驗證此方案的可行性。 -
The direct digital frequency synthesis ( dds ) is a kind of new frequency synthesis method and also a revolution in the frequency synthesis techniques. with the development of digital integrated circuits and microelectronic techniques, dds exhibits its advantages day by day
直接數字頻率合成（ dds ? digitaldirectfrequencysynthesis ）是一種新的頻率合成方法，是頻率合成技術的革命，隨著數字集成電路和微電子技術的發展， dds技術日益顯露出它的優越性。 -
Therefore, it has been widely used in the domains of communication, radar, navigation, etc. this article focuses on the generating of the function waves which include sine wave, triangle wave and square wave, depict the concepts of dds ( direct digital synthesis ) and surveying frequency on equal precision, analyze the key techniques in the development and present solutions of function generator. author also present the system structures of hardware and software, discuss the performance indexes and consider the possibility of the system. finally, with respect to the problems in debugging and testing process, author do some analyzing and present the practical solutions
本文主要圍繞函數發生器輸出的正弦、三角和方波三種基本波形的產生這一課題來展開，闡述了其中的直接數字合成（ dds ） 、等精度測頻等概念;分析了研製函數發生器所需攻克的關鍵技術，提出了技術解決途徑;對方案軟體進行編制和系統進行設計、安裝調試，實現了課題功能;最後針對調試中出現的問題，進行了較深入的分析，並提出了實際的解決措施。 -
This paper also discusses direct digital synthesis ( dds ) and digital signal process ( dsp ) in detail, because the application of digital technology is involved in software radio
本課題由於在軟體無線電中還涉及了數字技術的應用，因此對其中的關鍵部分直接數字頻率合成器（ dds ）和高速數字信號處理器（ dsp ）也進行了詳細地討論。 -
The primary work in this dissertation : ( 1 ) the principle, design and implementation of generating lfm / nlfm signals based on direct digital synthesis ( dds ) technology have been discussed especially, the system has been implemented all by author
本文的主要工作之處在於： （ 1 ）討論了基於直接數字合成（ dds ）技術產生直接中頻線性調頻脈壓信號和非線性調頻脈壓信號的工作原理、設計思想和工程實現方法，並獨立完成了系統的工程實現。 -
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，並就其理論設計和工程實踐問題進行討論。
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