direct digital frequency synthesis 中文意思是什麼
direct digital frequency synthesis
解釋
直接式數字頻率合成-
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 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 -
The thesis used a fully digital method that employed the principle of direct digital frequency synthesis to realize the modulation based on dsp
本文採用了完全數字化的方法，是利用直接數字頻率合成技術的原理，並基於dsp的系統實現msk調制。 -
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。 -
Aim at the development of the software radio in generalization, standardization and modularization, a waveform synthesis solution based on direct digital frequency synthesis is developed
針對國內外軟體無線電技術對通用、標準、模塊化的硬體平臺的需求，本文提出了一種基於直接數字頻率合成原理進行信號數字域調制的波形合成器設計方案。 -
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 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。 -
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。 -
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。 -
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。 -
It discusses some kinds of basic frequency synthesis technology such as direct, phase - lock, digital and direct digital frequency synthesis, then give the performance index of the frequency synthesis, and discusses the digital frequency synthesis technology in detail
討論了直接式頻率技術、鎖相式頻率合成技術、數字式頻率合成技術、直接數字頻率合成技術等幾種基本頻率合成技術，給出的衡量頻率合成技術的各種性能指標，並對全數字頻率合成技術作了較詳細的討論。
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