direct digital synthesis 中文意思是什麼
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 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。 -
This paper based on control theory, according to the conception of phrase lock loop and direct digital synthesis, we designed the clock circuit. it realizes the amalgamation of kinds of the ways about clock, which make it has some superiority
本論文在控制理論的基礎上，以鎖相頻率合成和直接數字頻率合成作為設計思想，搭建時鐘控制電路，在業界實現了多種時鐘控制電路實現方法的融合與統一，具有一定的優越性和領先性。 -
The agilent technologies 33250a function arbitrary waveform generator uses direct digital - synthesis techniques to create a stable, accurate output on all waveforms, down to 1 hz frequency resolution
Agilent 33250a函數任意波形發生器使用了直接數字合成技術，可在所有波形上產生頻率解析度達 -
You get standard waveforms along with the flexibility to create your own using direct digital synthesis for a stable, accurate output
除標準波形外，還具有使用直接數位合成得到穩定和精密輸出的靈活性。 -
The configuration that uses ieee - 13 94 to control a vxi system is introduced. chapter 2 describes the resource manager application of message - based device 13 94 - vxi controller and the mechanism of register - based device arbitrary waveform generator ( awg ). the key technology of interface circuit and direct digital synthesis in awg module is discussed explicitly
本文先對vxi總線技術進行了概略的介紹，在此基礎上，對一具體的vxi寄存器基任意波形發生器模塊進行展開，介紹了任意波形發生器模塊與vxi機箱背板總線通訊的介面電路部分及波形發生機理的核心部分的直接數字合成技術。 -
Based on that and the actual request, the thesis focuses on two ways of frequency synthesis : phase - loop locked and phase - loop locked + direct digital synthesis. then it introduces the concepts of group - delay and all - pass network, analyzes the theory of equalizing the group - delay of filter by all - pass network, simulates the design and sums up a perfect designing and debugging precept
中頻群延遲的均衡通過全通網路來實現，文中給出了信號傳輸中群延遲的概念以及全通網路的概念，詳細分析了全通網路用作群延遲均衡器的設計原理，並對設計進行了計算機模擬，給出了滿足要求的設計方案。 -
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。 -
At last we introduce the realization of all the parts, the problem in the circuit design and the measured data. the results show that the designed system has met the requirement. in this dissertation, direct digital synthesis technology has been used in the phase - locked frequency synthesizer, which can make full use of the characteristics of direct digital synthesis technology such as flexible output wave shape and continuous
本課題將直接數字式合成技術用於鎖相頻率合成器中，該方法將直接數字合成的特點，如輸出波形靈活且相位連續、頻率穩定度高、輸出頻率解析度高、頻率轉換速度快、輸出相位噪聲低、集成度高、功耗低、體積小等與鎖相環路的頻帶寬、工作頻率高、頻譜質量好等優點有機的結合起來，從而在寬帶的條件下實現了比較好的雜散性能和相噪。 -
The agilent technologies 33220a function arbitrary waveform generator uses direct digital synthesis techniques to create a stable, accurate output signal for clean, low distortion sine waves
Agilent 33220a函數任意波形發生器使用直接數字合成dds技術，可生成穩定精確純凈和低失真的正弦輸出信號 -
The essential requirements for the frequency synthesizer are : 1 ). low side band power 2 ). high hopping speed 3 ). short convergence time direct digital synthesis technology has the advantages of low cost, low power consumption, high frequency discrimination and short switching time
直接數字合成技術dds具有低成本、低功耗、高解析度和快速轉換時間等優點，是實現快速跳頻的一個關鍵技術。本文討論了如何實現高速的跳頻系統。 -
The agilent 33220a function arbitrary waveform generator uses direct digital synthesis techniques to create stable, low - distortion output signals so you get accurate results
Agilent 33220a函數任意波形發生器用直接數位合成dds技術產生穩定低失真的輸出信號，使您得到精確的結果。 -
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 dissertation use rebuild of combined telemeter system, which is the subsystem of the red - nine system developed by the aerospace measure and telecommunication incorporated company, as background, study and discuss frequency synthesize technology. the mostly task is to study how to use the direct digital synthesis technology to design and realize the high speed digital mid - frequency modulator, and give the answers of the problems which emerge in the development
本文以某測通公司研究生產的「紅九」系統中遙測模擬組合子系統為背景，對其中的數字中頻調制器的研究開發進行探討，主要任務是研究如何用直接數字合成技術進行高速數字中頻調制器的設計與實現、並提出了研發過程中所出現的問題的解決方案。 -
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。 -
After comparing several analog and digital generation methods of lfm signal, this paper confirms the system scheme as direct digital synthesis plus quadrature modulation. combined with agilent arbitrary waveform generator and phasor signal generator, a generation system is established and a ultra - wideband signal, whose bandwidth is 1ghz and carrier frequency is 4ghz, is generated
通過對幾種模擬與數字線性調頻信號的產生方法的比較，本文採用了以直接數字波形合成（ ddws ）加正交調制的系統方案，並結合實際的儀器設備，產生了帶寬為1ghz ，載頻4ghz的超寬帶線性調頻信號。
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