調頻檢波 的英文怎麼說
中文拼音 [diàobīnjiǎnbō]
調頻檢波
英文
fm demodulation- 調 : Ⅰ動詞1 (配合得均勻合適) harmonize; suit well; fit in perfectly 2 (使配合得均勻合適) mix; adju...
- 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...
- 檢 : Ⅰ動詞1 (查) check up; inspect; examine 2 (約束; 檢點) restrain oneself; be careful in one s c...
- 波 : Ⅰ名詞1 (波浪) wave 2 [物理學] (振動傳播的過程) wave 3 (意外變化) an unexpected turn of even...
- 調頻 : frequency modulation (fm); frequency adjustment調頻磁帶錄音機 f m magnetic tape recorder; 調頻...
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An electromagnetic wave of audio frequency produced by atmospheric disturbances such as lightning, having a characteristically decreasing frequency responsible for a whistling sound of descending pitch in detection equipment
嘯聲干擾一種由於諸如閃電等大氣干擾而產生的音頻電磁波,具有典型的逐漸減弱頻率的特徵,該頻減引起了檢波設備中調逐漸下降的嘯聲Effect of beat frequency on the measured phase of laser - diode heterodyne interferometry
斜波調頻合成外差干涉相位檢測非線性分析4. the signal data collected in expteriment are taken out in emulational research of system experiment. many methods such as adding window in frequency field, eliminating static object and so on restrain the width and sidelobe of static mussy weaves and detect out the target availably
4 、在系統實驗模擬研究中調出實驗採集信號數據,使用頻域加窗不加窗、清除靜態目標等方法很好地控制了靜態雜波干擾的幅度及旁瓣,有效地檢測出了目標。The master dissertation introduces passive correlative orientation system and base theory in signal dispose briefly in the first place. the system takes tv sound fm signal from tv satation signal. the power rate of tv station signal to sound signal is ten to one. in the case of submerged by mussy weave and machine ' s hot noise, dispersed target signal is feeble
系統採用電臺的電視伴音調頻信號,其中電臺信號與伴音信號功率之比基本為10 : 1 ,並且目標散射信號較弱,一般情況下淹沒在雜波和機器熱噪聲之下,採用常規的脈沖檢測方法很難對遠距離的目標進行檢測,而以電臺直達信號作為參考與目標回波信號進行相關檢測;系統中信號的相關處理會產生旁瓣,而強目標的旁瓣會影響附近的弱目標檢測。In the part of modulation and demodulation, we analyzed the principles of harmonic mixer, detectors, power dividers / combiners and branch - line couplers
對調制/解調器射頻電路部分,包括亞諧波混頻器、檢波器、功率分配/合成器和分支線耦合器基本原理進行了分析。The new technology of non - contact life - parameter detection is relative to that of the normal contact one, which uses microwave beams to illuminate the human subject, whose reflected wave will be modulated by the surface movement resulting from the physical activity. by this way, some parameters of the reflected wave, such as frequency and phase will be changed. if these changes can be detected, the life parameters such as respiration rate and heartbeat rate will be extracted from those changes
非接觸生命參數檢測是相對于常規的接觸式檢測而言的一種新技術,它利用微波束照射人體,其回波信號被人體生命活動引起的體表微動所調制,使得回波信號的某些參數(如頻率、相位)發生改變,檢測到這些變化就能從中提取出人體的生命參數(如呼吸或心跳) 。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。In this dissertation, radar detection in hrr has been taken as background. the followings are main contents of this dissertation : ( 1 ) based on analyzing the targets and the clutter ’ s specific characteristics of hrr radar, the echo models of targets and clutter have been studied respectively ; the changes of targets ’ echoes in different elevation angles, azimuth angles and attitude angles have been analyzed ; then, the echo models of lfm radar clutter have been established
本文針對高距離分辨雷達目標檢測開展研究,主要完成了以下幾方面的工作: ( 1 )分析了高距離分辨雷達目標和雜波回波特徵,在此基礎上分別研究了高距離分辨雷達目標和雜波的回波模型,分析了不同俯仰角、不同方位角以及不同姿態下目標回波模型的變化,並建立了線性調頻脈沖壓縮雷達的雜波模型。Detection performance and anti - jamming capability of phase - coded radar are also analyzed in this paper. the computer simulation shows that phase - coded radar has better property of suppressing jamming such as shortwave, gauss noise and binary phase code than lfm radar
本文還分析了相位編碼雷達的檢測性能和抗干擾能力,模擬結果顯示相位編碼雷達抗短波、高斯白噪聲、二相碼等干擾的能力優于線性調頻雷達。Balanced frequency modulation detector
平衡調頻檢波器It is composed of thirteen functin ? components including two 3 - db y - junction power splitter, two directional couplers, two waveguide attenuators and one polarizer of waveguide itself. the prominent feature of the device is that it has a beat detection function with respect to the single y - branch mioc device, and it plays an important role in improving the inertial - grade and the high precision steady - aim system because of the beat detection function. farthermore it has direct influence on the improvement of the high flexibility, shockproof and overload - resistance for the steady - aim system
器件的工作波長為1 . 3 m ,集分束器、合束器、起偏器/檢偏器、相位調制器、波導吸收器等十三個功能單元於一體,除了單y多功能集成光路器件具備的功能外,它還具有拍頻檢測功能,因而對提高慣導級和高精度穩瞄系統起著重要的作用,並直接影響著穩瞄系統的高機動性、抗沖擊力和過載能力的提高。From theoretical analysis, we know the existing demodulation methods have limitations as following : one is that the subtraction of the two signals frequencies will display as the result of demodulation when we demodulate two time - domain adding signals without modulating information ( fault information ) ; the other one is that aliasing phenomenon will occur as a result of getting absolute value, detection or square in the process of generalized demodulation analysis, such phenomenon will result in some superfluous frequency composition on the frequency spectrum, which will puzzle the detec tion of mechanical vibration. if the sampling frequency is selected from a suitable range, the aliasing phenomenon will be avoided ; the last one is that aliasing frequencies will be produced in zoom demodulation analysis because this algorithm cannot employ digital low - pass filtering to avert the folding frequencies of higher harmonics in the process of zoom sub - sampling
現有的解調分析方法存在以下三種局限性:將不包括調制信息(故障信息)的兩時域相加信號,也以其頻率之差作為解調信號而解出;廣義檢波濾波解調分析中,由於取絕對值、檢波或平方過程可能產生混頻效應,在解調譜中表現為無法分析的頻率成分,並由此推導出避免這種混頻現象的采樣頻率的選取范圍,從根本上避免此類誤診斷的產生;幾種細化解調分析新演算法中,因為無法在細化分析的選抽時進行數字低通濾波,有可能會出現調制頻率的高次諧波成分發生頻率混疊而反折到低頻部分的現象。Abstract : a software method of frequency - modulated signal demodulating based on wavelet packet is proposed in this paper. a variety of frequency - modulated signals are analyzed in time - frequency domain and the spectrograms are presented. this method can detect instantaneous frequency effectively and get frequency - modulated information, can be widely applied to dynamic testing and software radio
文摘:提出了基於小波包的調頻波解調方法,通過對各種調頻信號進行時頻分析,給出了信號的時間?頻率譜圖,能有效地檢測到瞬時頻率和獲取調頻信息,該方法可廣泛應用於動態測試和軟體無線電等領域。Lfmcw echo is modulated by doppler frequency. according to the characteristic, moving targets with different ambiguous velocities could be classified via mtd, but the range - velocity coupling problem still exists
線性調頻連續波雷達回波同脈沖雷達一樣受到了多普勒頻率的調制,通過動目標檢測( mtd )可抑制雜波,檢測運動目標。The concept of otn node transmission model is introduced. the requirement of otn node transmission model is discussed. this model uses the frequency domain transmission matrix to express the otn node transport characteristics. the simplified model based on wdm and im - dd systems, the relationship between node characteristics and model parameters and measurement of model parameters are also discussed. at last a briefly discussion on how to develop the otn simulation and cad software based on our model is demonstrated
在線性時不變的假設下,提出利用頻域傳輸矩陣來表示節點傳輸特性的方法給出了oxc和oadm兩類光傳送網節點的統一的表示根據目前通用的波分復用強度調制直接檢波系統的特點對復雜的頻域傳輸矩陣進行了簡化並對通常所關心的節點主要性能指標與模型參數的關系模型參數的測量和計算模型的設計與計算機模擬輔助設計軟體開發的銜接問題進行了討論。In the design, the diode of agilent ' s hsch - 9161 is used. with the diode circuits in parallel, the millimeter - wave short pulse detector has been designed. it works at the frequency of 37 to 38ghz, and the pulse duration is 400ps
本文採用agilent公司的hsch - 9161檢波二級管,選取二極體並聯檢波電路形式,完成了工作頻率為37 ~ 38ghz 、脈沖寬度為400ps的毫米波短脈沖檢波器的研製,同時設計了一個毫米波短脈沖調制器。After analyzing the theory of mtdi and setting up the model of moving target echoes, the dissertation discusses in detail the effect of moving target doppler center frequency and doppler rate on the conventional sar image. it also analyzes detailedly the range migration of moving target from time field and frequency field and provides migration model in both fields. after that, it divides algorithms of mtdi into several classes, analyzes the influence of signal - to - noise on the detection results and gives the flow chart of moving target imaging processing
本文的主要貢獻包括: 1 、建立了運動目標回波散射模型,深入探討了進行常規sar成像時,動目標的多普勒中心頻率和調頻率對動目標圖像造成的影響;從時域和頻域兩方面詳細分析了由於目標運動造成的距離徙動效應,建立了距離徙動模型;然後研究了動目標檢測原理,並對現有的檢測方法進行分類,使之更加系統化;詳細分析了動目標信噪比對檢測結果的影響,給出了sar系統動目標成像流程圖,指出了動目標成像中的關鍵環節。First of all, by establishing the observation model of complex harmonic signal and complex linear chirp signal respectively under the co - jamming of additive and multiply noise, the paper constructed cyclic moment detectors of different orders, deduced snr expression of the detector through theoretic analysis, discussed the relation of detector performance and noise statistical characteristic. the curve of detection performance is obtained through monte carlo simulation test, proving the related conclusion derived
首先,論文分別以加性和乘性噪聲聯合干擾下的復諧波信號和復線性調頻信號為觀測模型,構造了基於不同階次的循環矩檢測統計量,從理論上推導出了檢測器的信噪比表達式,分析了檢測器性能與噪聲統計特性的關系,通過monte - carlo模擬試驗得到了檢測性能的曲線,驗證了推導的有關結論。- 2. in order to accomplish the extraction measuremellt of distorted wavefront on specific plane of a laser beam, a crsi ( cyc1ic radial shearing interferometer ) based on relay imaging technique was built. the experiinental result on this crsi shows it can used to test the spatial mid and low frequency wavefront distortion
二、為了實現激光光束在確定平面上的波前畸變的準確檢測,採用中繼成像技術建立了一套基於空間相位調制的環路徑向剪切干涉波前傳感硬體系統,實驗證明,它可用於中低頻段波前畸變的檢測。The control of the spatial mid frequency wavefront distortion was achieved based on our cri wavefront sensing and lctv wavefront correcting system. the results of our research show that crs interferometer can be used to diagnosing the mid and low frequency wavefront distortion of a laser beam and lcslm can be used to availably controlled it
通過以上研究,說明我們建立的環路徑向剪切干涉儀可以用於icf激光驅動器的中低段波前畸變的檢測,並且液晶空間光調制器可用於它的前級中存在的中頻段波前畸變的校正。分享友人