例句與造句

1. Study on direct digital frequency synthesizer technology based on piecewise pperation
   基于分段運(yùn)算的直接頻率合成技術(shù)研究
2. 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(shù)字頻率合成器( dds )的基本結(jié)構(gòu)、工作原理、雜散來(lái)源、輸出頻譜特性。
3. 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(shù)字頻率合成器是現(xiàn)代頻率合成的主要工具,它有頻率分辨率高,頻率轉(zhuǎn)化快等眾多優(yōu)點(diǎn)。
4. 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(duì)幾十年頻率合成器的發(fā)展進(jìn)行概述,而后針對(duì)本次設(shè)計(jì)的重點(diǎn),對(duì)應(yīng)用較為廣泛的鎖相頻率合成理論進(jìn)行了深入的探討,詳細(xì)介紹了鎖相環(huán)的工作原理、組成結(jié)構(gòu)和鎖相類型,并對(duì)鎖相頻率合成器的相噪特性進(jìn)行了研究分析,包括有源環(huán)路濾波器對(duì)于相噪的影響,提出了改善相位噪聲的幾點(diǎn)措施:改善環(huán)路形式、降低分頻數(shù)、增大鑒相頻率等。接著介紹了直接數(shù)字頻率合成器( dds )和注入鎖相電路的原理特點(diǎn)以及相噪分析,它們也是本次設(shè)計(jì)的重要電路。
5. 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(shù)字頻率合成器是一種全數(shù)字化的頻率合成器，由相位累加器、波形rom 、 d a轉(zhuǎn)換器和低通濾波器構(gòu)成， dds技術(shù)具有頻率分辨率高、頻率切換速度快、頻率切換時(shí)相位連續(xù)、輸出相位噪聲低和可以產(chǎn)生任意波形等優(yōu)點(diǎn)。
6. It's difficult to find direct digital frequency synthesizer in a sentence. 用direct digital frequency synthesizer造句挺難的
7. 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(dá)的預(yù)研項(xiàng)目? ? 《戰(zhàn)術(shù)抗干擾通信電臺(tái)綜合測(cè)試技術(shù)》中的信號(hào)源部分(捷變頻信號(hào)發(fā)生器中的dds信號(hào)源部分) 。
8. 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(shù)字合成( dds )技術(shù)的工作原理,對(duì)比了直接數(shù)字波形合成( ddws )及直接數(shù)字頻率合成( ddfs )兩種數(shù)字波形產(chǎn)生方法,并就其理論設(shè)計(jì)和工程實(shí)踐問(wèn)題進(jìn)行討論。