相干頻率合成 的英文怎麼說
中文拼音 [xiānggānbīnlǜgěchéng]
相干頻率合成
英文
coherent frequency synthesis- 相 : 相Ⅰ名詞1 (相貌; 外貌) looks; appearance 2 (坐、立等的姿態) bearing; posture 3 [物理學] (相位...
- 干 : 干Ⅰ名詞1 (事物的主體或 重要部分) trunk; main part 2 (幹部的簡稱) short for cadre Ⅱ動詞1 (做...
- 頻 : Ⅰ形容詞(次數多) frequent Ⅱ副詞(屢次) frequently; repeatedly Ⅲ名詞1 [物理學] (物體每秒鐘振動...
- 率 : 率名詞(比值) rate; ratio; proportion
- 合 : 合量詞(容量單位) ge, a unit of dry measure for grain (=1 decilitre)
- 成 : Ⅰ動詞1 (完成; 成功) accomplish; succeed 2 (成為; 變為) become; turn into 3 (成全) help comp...
- 相干 : 1 (多用於否定句或疑問句) have to do with; be concerned with 2 [物理學] coherent; 相干散射 coher...
- 頻率 : frequency; rate
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A building of high, the breadth, long comparison is very important. house for combination in an ideal of big set, reruns hour then contain the best frequency to respond to the width. frequency response range in other words, the combination can broadcast tallest to can also fully develop to the lowest frequency, and the equilibrium degree is as well high, and halt a circumstance is very tiny. the first glint wave primary reflection mutual interference for with wave secondary reflection of many glints the degree is not to result in confusion. combination that fundermental the diapason wave harmonics is again perfect
大套組合在一間理想的房子里,重播時便有最佳的頻率響應寬度frequency response range 。換句話說,組合所能播放的最高至最低頻率也可以盡情發揮,平衡度亦高,駐波情況極微。第一反射音波primary reflection和多次反射音波secondary reflection的互相干擾情度不至造成混亂。By making full use of favourable narrow - band tracing filter character of pll and by combining the merits of dds such as super fine frequency resolution 、 high frequency accuracy 、 very fast frequency hoping with it, the pll / pll + dds frequency synthesizer presents wide band high quality source and super small frequency hoping step. while the electronically tuned filter abates the image interference and notably improves the selectivity. the theorem of frequency synthesizer and center - frequency - fixed filter is simply but adequately introduced first in this paper
課題中所採用的pll或dds pll鎖相頻率合成方法充分發揮鎖相環良好的窄帶跟蹤濾波特性,並結合dds的高頻率解析度、高頻率精確度和高速頻率捷變等優點,分別實現了系統所要求的高質量寬帶本振源和小步長頻率捷變;採用電調諧選頻技術,則大大改善了接收機的選擇性和抗干擾能力。A cyclic radial shearing interferometer was used to diagnose the wavefront distortion of a laser system and an lcslm ( liquid crysnd spatial ligh modulator ) was used to control it. some results have been summarized as follows : l. according to the theory of scalar quanity diffeaction and the model of the random gaussian phase screen of low frequency wavefront, the effect of the low frequency wavefront with different rms gradient on the focal spot of a laser beam was studied
本論文在激光光束波前畸變檢測和控制上進行了新的探索,主要就空間相位調制環路徑向剪切干涉儀以及它對波前畸變的檢測和液晶空間光調制器及其對中頻段波前畸變的控制進行了研究,其研究的內容和取得的成果如下:一、根據標量衍射理論,結合低頻波前畸變的高斯隨機位相分佈模型,研究了不同均方根梯度低頻畸變波前對激光光束焦斑聚焦性的影響,並採用描述中頻段波前畸變的功率譜密度概念,模擬計算了它對激光焦斑旁瓣的貢獻。The some fire control system is an advanced multi - senor short range air defense system, which integrated both x and ka bands searching and tracking radars, laser range finder, combined the control computer of subsystem with the master computer, and applied the technology of data fusion
摘要某火控系統集兩個頻率波段的搜索雷達、跟蹤雷達和電視跟蹤器、激光測距機於一體,分系統控制處理計算機與系統主計算機相結合,採用了數據融合技術,是一部多傳感器集成的現代化防空系統,具有搜索性能好、反應時間快、抗干擾能力強、自動化程度高、使用性能好等特點。Some valuable conclusions are summarized by theoretical analysis and simulation experiments : from the side of signal processing, pulse jamming can be deleted by the method of time - domain sliding window accumulation and can be restored by interpolative prediction. ; gauss white nose can be attenuated while jamming disperse point - target by the method of time - frequency analysis in time - frequency domain. ; radio frequency noise jamming can be deleted by the method of average range frequency spectrum and notching in frequency domain
通過大量的理論分析和模擬實驗,得到了一批具有一定價值的結論:從信號處理的角度出發,對于脈沖式干擾,能夠運用時域滑動窗口積累的方法去掉,並且通過預測插值得到較好的恢復;對于高斯白噪聲干擾,在時頻變換域內應用時頻分析方法可減小其對分散點目標的干擾;對于射頻噪聲,通過平均距離頻頻法和頻域陷波的方法可以去掉;從改變合成孔徑雷達系統角度出發,類似雙基地雷達能夠避免各種干擾,對發射信號進行調幅,調相以及改變調頻斜率都是較好的抗干擾方法。In this paper, a simplified method of calculating wind - induced response and design loads of super - high - rise buildings was proposed. coherence properties of wind load on typical tall building were analyzed and the results show that cross - wind loads at different height have strong coherence at vertex shedding frequency, and the coherence function ' s value here is near to 1
首先分析了各測點層合力的相干特性,結果顯示各測點層所受順風向風荷載之間的相干函數基本成單調衰減規律,而橫風向脈動風荷載在漩渦脫落頻率處存在和順風向不同的顯著相關性。Then on one hand, author makes researches of anti - jamming against pulse jamming 、 gauss white noise jamming and radio frequency noise jamming from the side of signal processing. author exercises much signal processing knowledge of time - domain sliding window accumulation 、 wavelet analysis 、 time - frequency analysis and linear prediction and carries out many simulation experiments. on the other hand, author proposes the anti - jamming methods of using a sar similar to double - base radar and modulating the amplitude 、 the phase of emission signal and changing the frequency modulation slope from the side of changing sar system model
作者首先提出了合成孔徑雷達抗干擾的定義、分類以及評價抗干擾方法好壞的主客觀標準;然後,一方面從信號處理的角度出發對脈沖式干擾、高斯白噪聲干擾以及射頻噪聲干擾進行了抗干擾研究,其中運用了時域滑動窗口積累,小波分析,時頻分析以及線性預測等信號處理知識,做了大量的模擬實驗;另一方面,本文基於改變合成孔徑雷達系統模式提出了利用類似雙基地雷達來抗干擾,以及對發射信號進行調幅、調相以及改變調頻斜率來抗干擾,同樣做了相應的模擬實驗。The problem of signal processing for direct - sequence code - division - multiple - access ( ds - cdma ) signal over multipath frequency - selective mobile channels is considered. a new blind receiver is proposed. without the knowledge of the multiple - access interference users spreading code and the channel characteristics, the receiver achieves blind detection with prior knowledge of only the desired users spreading code and approximate timing. by using reduced rank adaptive decorrelating filter and adaptive multipath combiner which is based on decision - directed algorithm, the receiver gets the ability to combat both fading and the near - far effect at low cost. simulation results demonstrate that the proposed receiver offers high performance
本文研究多徑頻率選擇性衰落通道下直接序列擴頻碼分多址( ds - cdma )信號的處理問題,提出了一種新型的盲接收機.該接收機不需預知多址干擾用戶的擴頻碼,不需預知通道參數,只需已知期望用戶的擴頻碼和粗略的定時,就可以完成用戶的盲檢測.同時,該接收機通過降維自適應去相關濾波和基於判決指導的自適應多徑合併,來獲得低成本和良好的抗衰落、抗遠近效應性能.模擬結果驗證了本文提出的接收機的優良性能Aperture synthesis sonar, as its name implies, synthesizes an aperture by storing successive echoes obtained from a moving platform and by processing the results as if they had been obtained from a multi - element array enables a high azimuth resolution to be obtained from a physically small array
合成孔徑聲納,顧名思義就是通過小孔徑物理聲陣的勻速直線運動,將沿航跡方向的回波數據相干累加,形成較大的虛擬孔徑,從而提高方位解析度。合成孔徑技術相對于常規聲納技術的突出優勢在於,它只利用小孔徑的物理聲陣,就可以得到與徑向距離和頻率都無關的高方位解析度。分享友人