frequency modulation method 中文意思是什麼

frequency modulation method 解釋
調頻法
  • frequency : n. 1. 屢次，頻仍，頻繁。2. （脈搏等的）次數，出現率；頻度；【物理學】頻率，周率。
  • modulation : n 調整，調節；（聲調的）抑揚，變化；【音樂】轉調，變調；【無線電】調制。 amplitude modulation 振...
  • method : n 1 方法，方式；順序。2 （思想、言談上的）條理，規律，秩序。3 【生物學】分類法。4 〈M 〉【戲劇】...
  1. Any subtle change of capacitance can be measured through the method of modulation on high - frequency harmonic oscillation return circuit

    電容的微小變化可通過對高頻諧振迴路調制的方法進行測量。
  2. Presents the model proposed for analyzing the vibration characteristics of shrouded blades and their calculation method by employing a wave propagation theory and modal synthesis technology coupled with a finite element method from the view point it is possible not only to conduct frequency modulation of the shrouded blades of a gas turbine, but also to utilize the friction effects between them to dissipate energy, thereby attaining the aim of vibration alleviation, as shrouded blades have been widely used in the design of high - speed turbomachinery, such as modern gas turbines and steam turbines, and with the shrouded blades forming an integral whole in a centrifugal force field, the vibration characteristics of the whole ring of blades are different from those of a single isolated blade, and this makes it essential to take into account the integral effect of blade shrouds, concludes from the calculation examples and engineering application that the above approach is valid and correct along with the possibility of considerably reducing the scale of calculation and analysis, and points out it is necessary to take into consideration the coupled effect of the whole ring of blades while the dynamic characteristics of shrouded blades is being analysed

    帶冠葉片不但能調頻，還可以利用葉冠之間的摩擦效應來耗散能量，達到減振的目的.帶冠葉片在離心力場中形成一整體，其整圈葉片振動特性不同於單個孤立葉片，需考慮葉冠的整體效應.利用帶冠葉片系統的循環對稱性，提出了採用波傳播理論和模態綜合技術，結合有限元方法研究燃氣輪機帶冠葉片振動特性的分析模型和計算方法.算例和工程應用證明了該方法是效性的、正確的，並可以大大降低計算分析規模.研究表明帶冠葉片動力特性分析時必須考慮整圈葉片的耦合效應
  3. The carrier wave is modulated directly by the baseband signal at several frequency point in l band and s band. firstly, this paper clarifies the theory of i / q modulation, elaborates evm and acpl, and analyzes the effect of amplitude and phase unbalance and dc offset on evm. secondly we review the basic principle of phase locked loop and it ’ s composing parts, including the basic conception and design method of pll frequency synthesizer, especially introduce the charge pump pll frequency synthesizer in detail

    首先，在闡述i / q正交調制基本原理的基礎上，通過對誤差矢量和鄰近通道功率泄漏的詳細分析，定性、定量地討論了各種非理想電路因素（如相位不平衡、幅度不平衡、直流偏差等）對調制器性能的影響;其次，介紹了鎖相環的工作原理和基本組成部分，包括鎖相環的設計和環路濾波器的設計，特別詳述了電荷泵鎖相頻率源;第三，介紹了採用直接調制技術模擬衛星信號的射頻前端的設計;最後，對整個直接射頻調制系統進行測試，結果基本上達到了課題要求。
  4. The nucleus is the software in the design and realization of virtual instruments. we use the design method of module and use many papers to describe the whole building process of the typical signal generation module, date handling module, date reading and writing module, resultdemonstrate module. as the conclusions, we also offer the panels and the diagrams of virtual signal frequency spectrum analytical instrument, virtual butterworth filter, virtual signal generation instrument, virtual integrator and differentiator regulator and amplitude modulation wave counter modulation instrument

    本文採用模塊化設計方法，詳細描述了典型信號生成模塊、數據處理模塊、數據讀取和存儲模塊、顯示模塊等軟體開發的全過程，分析、解決了設計及實現過程中出現的問題，並給出了已實現的虛擬信號頻譜分析儀、虛擬巴特沃斯濾波器、調幅波解調器、虛擬信號發生器、虛擬積分器和微分器等實驗教學用虛擬儀器的前面板圖和程序流程圖。
  5. 3 using current injecting frequency modulation method and modulating sine wave around the resonator point, the lock - in phenomena is observed in a comparatively short period of time. this has achieved the basic goal for a closed loop r - fog

    3 、採用電流注入法，在諧振點附近進行正弦調制，實現了對諧振點的短時間鎖定，達到了閉環光纖陀螺設計的首要基本要求。
  6. In this thesis, complex analytical band - pass filtering based method is proposed to reduce the modulation complexity ; polyphase decomposition is used to reduce the filtering complexity ; uniform dft filter banks based method exploits the center frequency distribution characteristic of filter banks to reduces the modulation and spectral resort processes

    而基於均勻dft濾波器組的演算法充分利用了濾波器組的中心頻率的分佈特點，省略了復頻移環節和整序環節，同時利用多相分解的方法改善了濾波環節，兼有各種方法的優點而大大的提高了演算法的實時性。
  7. 2 through altering the length of the resonator, more clear resonator characteristic is observed, which proves that using the method of altering the length of the resonator may be a better way that using current injecting frequency modulation

    浙江大學碩十學位論文2 、川改變諧振腔腔長的方法，觀測到了更為清晰的諧振曲線。證明采川改變腔長的方法來實現調頻，比采川電流調頻的方法可能更為優越。
  8. Orthogonal frequency division multiplexing ( ofdm ) is a multi - carrier modulation method

    正交頻分多路復用是一種多載波調制技術。
  9. 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。
  10. People can easily design the hysteresis current control hardware circuit, but the switching frequency is variable which makes us difficult the design the output filter, moreover the output waveform is not good. the space vector modulation techniques, by selecting the zero vector properly, it can reduce the harmonic content of the output voltage, so it has become a popular control method

    滯環電流控制的硬體電路設計簡單，但存在開關頻率不固定，輸出濾波器設計困難，輸出波形質量差，空間矢量控制（ svm ）技術具有較高的電壓利用率，且通過對零矢量的合理控制可以降低諧波含量或降低開關損耗，因此是一種較好的控制方法。
  11. Besides these, it is capable of performing frequency conversion with sinusoidal output voltages and currents at the desired output frequency and allows bi - directional power flow according to the space vector modulation method of the equivalent structure of the ac - dc - ac conversion, the conversion relations of the matrix converter were deeply investigated. the ac - ac direct transformation control and the double - space - vector pwm scheme of the matrix converter were deduced and the modeling, sin ~ iu1ation and experiment of a three - phase matrix converter were implemented

    本文從等效交一直一交變換的空間矢量調制方法出發，深入分析了矩陣式變換器的變換關系，推導出了交一交直接變換控制規律和雙空間矢量pwm調制技術，實現了交一交直接變換控制方式下矩陣式變換器的建模和運行分析，並進行了計算機模擬和實驗研究。
  12. In order to solve the problem of direct torque control ( dtc ) for permanent magnet synchronous motor ( pmsm ) related to the flux and the torque ripple and the uncertainty of switching frequency, a method which shorten the voltage - vector - function - time by svm ( space vector modulation ) is developed, and in order to improve the system performance, the stator flux linkage sectors and vectors are subdivided

    摘要為了解決永磁同步電機傳統直接轉矩控制低速時磁鏈和轉矩脈動大的問題，提出了1種用空間矢量調制（ svm ）實現減小電壓矢量在1個控制周期中的作用時間的直接轉矩控制方法;為進一步提高系統性能，對磁鏈扇區和電壓矢量進行了細分。
  13. A method of representing data in magnetizable surface storage ; for example, “ modified frequency modulation ”

    在磁表面存儲技術中一種表示數據的方法，例如改進型調頻制。
  14. The main results and creative points in the dissertation were as follows : a ) by means of studying on the fiber - optic hydrophones ’ tdm array based on phase generated carrier ( pgc ) demodulation with laser frequency modulation, the mathematic models were set up, used for theoretical analyses of noncoherent crosstalks in the system using low coherent laser and coherent crosstalks in the system using high coherent laser. the formulas calculating crosstalks were given, and the method measuring crosstalks was shown definitely

    本論文的主要研究結果和創新在於: 1 、通過對基於光頻調制pgc （相位生成載波）解調光纖水聽器時分復用系統的研究，針對低相干光源的串擾強度迭加和高相干光源串擾的相干迭加，建立了理論分析的數學模型，得出了計算串擾的公式，明確了測試系統串擾的方法。
  15. For ac discrete digital signal, the zero - calculating method is applied to calculate the true zero in the periodic signal. for the measurement of ac and dc voltage spectrum, the faster fourier transform ( fft ) is used. to measure dc voltage ripple spectrum and frequency modulation of ac voltage, the digital filter is used

    其中對于交變的離散數字量，採用零點撿出技術計算周波信號的真實過零點；對于交直流電壓頻譜，採用快速傅立葉變換進行頻譜分析；對于直流電壓脈動和頻率調制，採用數字濾波器進行濾波后再做分析處理。
  16. The above waveforms discussed are to synthesize the wb or uwb with narrow band pulses. assuming the transmitting uwb linear frequency modulation ( chirp ), dechirp processing is introduced, and the method involved to obtain high resolution by reducing the if bandwidth is presented. furthermore, dechirp processing used to sar imaging is discussed, and the processing steps are described

    < wp = 4 >以上研究的兩種信號形式都是通過窄帶子脈沖串相參合成的方法來獲得超寬帶回波信號，本文還探討了去斜率（ dechirp或stretch ）方法，分析了去斜率降低接收機中頻帶寬、 fft獲得目標一維距離像的原理，並探討了線性調頻去斜率合成孔徑雷達成像，給出了具體實現步驟。
  17. The system employs multicarrier modulation ( mcm ) technique as the modulation method, and linear frequency modulation ( lfm ) signal as the synchronization signal and digital signal processor ( dsp ) as the hardware ' s core chip

    該系統選用多載波調制技術進行調制，選用線性調頻信號為其同步信號，選擇數字信號處理器為硬體核心晶元。
  18. In the end, this thesis tests the resonator with three methods in case that it is both open looped and closed looped, and gets the results listed below : 1 taking 1 mhz frequency width ld as the light source, using current injecting frequency modulation method, the output characteristic of the resonator is got, which proves that the laser used in the lab can be used to modulate the frequency using current injecting frequency modulation

    本文最後採用三種不同的方法對諧振式光纖陀螺進行了開環和閉環的實驗測試，並取得了以下實驗結果： 1 、用頻寬1mhz的ld作光源，採用電流注入調頻的方法，觀測到了諧振腔的輸出特性曲線。證明了實驗採用的激光器可以通過注入電流的方法實現調頻。
  19. The most important specification of the level measurement system is the accuracy. the range measurement accuracy of a fmcw radar is strongly affected by the stability and the linearity of the frequency modulation. thus the vco ' s nonlinearity correcting method is discussed

    利用fft （ dft ）頻譜估計頻率精度受fft頻率量化（即譜線之間的間隔）的限制，對應的fmcw雷達的距離估計精度則受掃頻帶寬的限定。
  20. 2 a mathematical model of the reflected signal based on the frequency modulation continuous wave ( fmcw ) radar, solving the frequency - azimuth estimation of coherent signals by spatial smoothing technology, comparing the resolution of the object based on two - dim music method and that based on two - dim fft

    2討論了在接收dbf條件下，回波信號的二維譜估計技術。建立了基於調頻連續波體制雷達下回波信號的數學模型，並將空間平滑技術推廣到時-空二維譜估計，解決了相干信號源的頻率-方位估計問題。
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