phase-frequency characteristics 中文意思是什麼

phase-frequency characteristics 解釋
相頻特性
  • phase : n 1 形勢,局面,狀態;階級。2 方面,側面。3 【天文學】(月等的)變相,盈虧;【物、天】相,周相,...
  • 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。
  • characteristics : 產品性能描述
  1. In the fourth chapter, firstly, the fsk / psk signal function is presented, then, the signal which frequency and phase are modulated by costas code and barker code for each are analyzed at the same time. after that, the target returns and clutter returns are analyzed and modeled. at last, both of the time correlation characteristics and space correlation characteristics are theoretically analyzed

    在第四章中,首先給出fsk / psk信號的表達式,並對一種分別採用costas碼和barker碼進行頻率和相位調制的fsk / psk信號進行分析,然後對fsk / psk信號的目標回波和雜亂回波進行分析與建模,接著,對雜波信號的時間相關性和空間相關性進行理論分析,由分析結果可知, fsk / psk雷達雜波的時間相關性不變、空間相關性增強。
  2. Through analysising the characteristics of the power system with floating neutral point deeply, the paper puts forward a new plan of single - phase to ground fault line selection on the base of s ' s signal injecton method and gives the hardware and software design. in this design, the high speed sampling and data processing is carried out through using dsp processor ; the large electrice current is drived through the application of a high - performance audio power amplifier and transformer ; the communication between host computer and detectors is realized through rs485 bus technology ; the difference multilevel frequency - selected amplifier is designed and the feeble signal of space is sampled on the base of the theory of magnetic induction ; the interface between dsp and exterior chip and rs485 interface logical is designed through using fpga ; the using of lcd module and keyboard interfacing chip makes the interface between human and machine ; the programme of host computer and detectors is designed through using blocking design method

    在本設計中,採用高速的dsp處理器,實現了對故障特徵信息的高速採集與處理;採用大功率的功放晶元與變壓器配合的方法,實現了大電流信號的驅動輸出;採用485總線技術,組建了裝置主機與多探測器之間的主從式通訊網路,實現了多干擾條件下裝置主機與多探測器的可靠通訊;設計了差分式多級選頻放大電路,採用磁感應的方法實現了對空間微弱信號的接收;利用fpga技術,實現了控制器與多外設的介面及數字信號的串並轉換;採用了先進的lcd液晶顯示模塊及鍵盤介面晶元,設計了人機信息交互的介面;採用了模塊化的軟體設計方法,開發了裝置主機及探測器的軟體程序。
  3. Log phase - frequency characteristics

    對數相頻特性
  4. The study has completed the design of two - phase inverter and made up of the two - phase inverter - motor system for experimental use it is a variable frequency adjustable speed system with a open - loop control of rotational speed, which consists of voltage - controlled oscillator circulating assign device inverter circuit and two - phase induction motor a accurate mathematical model is set based on the whole system, and simulator program of dynamic and steady condition is established, which is used to calculate the dynamic and steady performance by kron and symmetrical coordinate converter by simulator calculation and experimental research with specific parameter of the system, a comparison is made between predicted and experimental characteristics, experimental measurements are shown to compare closely with corresponding theoretical result it is compared with some variable frequency adjus table speed system comprising inverter and single - phase induction motor from the system efficiency torque pulsation and the effect of two - phase inverter capacitance based on the conclusion, harmonic cancellation pulse width modulation control of a two - phase inverter - fed induction - motor drive system is researched, which cancelled the low harmonic and improve the system performance

    通過對電機的kron變換和對稱分量變換,建立了系統較精確的數學模型,編制了系統動態及穩態運行的模擬計算程序分別計算系統的動態和穩態性能。通過對系統的具體參數進行了模擬運算和實驗研究,實驗和模擬結果進行比較,說明實驗和理論較為一致,並從系統效率、轉矩脈動及兩相逆變器電容的影響等方面與各種逆變器和單相異步電動機組成的變頻調速系統加以比較。在此基礎上,對兩相逆變器供電-異步電動機系統使用諧波抑制pwm控制進行了研究,由於減少了低次諧波,改善了系統性能。
  5. The fundamental theory and equations for the pressure fluctuation are described and the wall pressure fluctuation is measured. based on the experiment data, the characteristics of pressure fluctuations are analyzed in the three - phase flow of water, air and sand. the effects of air concentration and sediment content on the amplitude and frequency of pressure fluctuations are discussed

    建立了多相流壓強脈動基本方程,闡述了水流脈動壓強基本理論,分析了壓強脈動機理;根據試驗數據,探討了水、氣、沙三相流體的壓強脈動特性,初步得到了高速含沙摻氣水流脈動壓強的幅值特性與頻域特性;提出了脈動壓強強度系數、脈動壓強極差系數與含沙量、摻氣濃度的關系。
  6. Frequency code is not uniformity distribution and keeps to a probability distribution function defined by the spectral characteristics of the target of interest. the phase code is equally duality pseudo - random sequence and used to reduced the sidelobes of the signal correlation function. and the mismatch - phase sequence is corresponding with the frequency sequence one by one

    而頻率編碼為不均勻分佈,由所觀測目標的頻譜信息提取出概率密度函數決定頻率編碼序列的分佈;相位編碼為二元的偽隨機序列,採取均勻的二相編碼,消減同頻脈沖帶來的過高的相關函數的旁瓣;而失配相位為與頻率編碼相一一對應于各子脈沖中。
  7. It can be deduced from the characteristics of ilpll circuit that injection - locking bandwidth is not only related to the injection - locking bandwidth without feedback loop, but also related to the characteristics of frequency mixing, loop gain and the change of the loop phase. thus, the needed bandwidth can be obtained by adjusting the loop parameters. and the phase noise characteristics are mainly determined by loop transmission factor

    由ilpll電路特性的推導得出:注入鎖定帶寬不僅跟開環時的注鎖帶寬有關,而且與混頻特性、環路增益以及環路相位變化相關聯,可以通過調節環路的參數得到所需帶寬;相噪特性主要由環路傳輸因子決定,可以通過調節環路濾波得到比開環注入鎖定相噪更優的特性。
  8. In order to reflect the characteristics of amplitude increase and frequency changing of seismic signal, a new automatic recognition method of seismic phase is developed based on the instantaneous amplitude and instantaneous frequency

    摘要為了充分反映地震信號振幅增大和頻率改變的特徵,發展了一種以振幅和瞬時頻率比乘積為特徵參量的震相自動識別方法。
  9. The basic operation principle of phase - locked frequency synthesizer and the type of circuits are expatiated systematicly in this paper. the principle of operation on sampling phase detector and some characteristics including the linear tracking and phase noise in phase loop circuits are analyzed deeply. the research is emphased on the theory and design method of circuits in the sampling phase - locked frequency synthesizer. then, the expansion capturing circuit is analyzed and designed for better performance of capturing loop circuits. at last, the loop filter is also analyzed and contrived taking account of effection of additional phase shift by the sampling - holder. the general research on the theory and technology of sampling phase lock in the paper will make a basement for the development of new product

    本文系統的闡述了鎖相頻率合成器的基本工作原理及電路類型;較深入地分析了取樣鑒相工作原理及電路、鎖相環路的線性跟蹤特性和相位噪聲特性;重點對取樣鎖相頻率合成器電路理論和設計方法進行了研究;為了改善環路的捕獲性能,對擴捕電路進行了分析和設計,並用wewb32軟體對電路進行了模擬;考慮到取樣保持器的附加相移影響,對環路濾波器進行了分析和設計。
  10. The research on the rf characteristics of the conductor - centered helical groove sws. ( a ) in the " cold " system, we found that the changing of depth of the groove has no distinct effects on the phase velocity at the lower frequency region ; but with the increasing of the frequency, the phase velocity and bandwidth are reduced slightly, the structure is more dispersive and the coupling impedance is enhanced

    對具有中心導體軸的矩形螺旋槽慢波系統的高頻特性進行了理論研究: ( 1 )在冷系統中的研究結果表明:頻率較低時,槽深的改變對相速的影響不是很大,隨著頻率的增大相速略有減小,同時帶寬也有所減小,色散變得稍強,耦合阻抗增大。
  11. Phase - frequency characteristics

    相頻特性
  12. It ' s an important factor to measure phase difference for studying phase frequency characteristics of the network

    摘要相位差的測量是研究網路相頻特性的一個重要方面。
  13. In this paper, the author comprehensively expatiates the research on microwave phase in - lock frequency modulation. at first, the background of reentry telemetry system and the features of pcm telemetry system are presented, and then the author mainly discusses the application of phase in - lock fm techniques in the design of pcm transmitter and the analysis of characteristics of binary pcm reentry telemetry channel

    在文章的前面,作者簡單介紹了目前再入遙測技術發展現狀和pcm系統的特點;然後給出了二元pcm再入遙測通道的系統分析和高碼速率數據傳輸實現的主要途徑;在文章的第三部分,討論了鎖相調頻技術及其在pcm遙測發射機中的實際應用。
  14. 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。
  15. Phase modulation system is a superior system, can transmit data at high rate. in this thesis, digital fh - mpsk and fh - / 4dqpsk modulator and demodulator are given according to the frequency - hop communication characteristics. at last, we implement these systems in both hardware and software platform

    本文根據跳頻傳輸的特點,對mpsk和4 - dqpsk這兩種相位調制方式進行分析,提出數字調制解調方案,並用matlab對其進行了模擬,最後還在ti公司的tms320c6416晶元上實現了這兩種系統。
  16. 1. upon brief reviewing current mathematical and physical models and mechanisms for electrorheological effect, the theoretical analysis of the dielectric relaxation of electrorheological fluids and the frequency - inducing characteristics for electrorheological effect are conducted. based on statistical thermodynamic analysis and osmotic pressure calculating of an electrorheological fluid complex system, phenomenological theory is adopted to evaluated phase reparation characteristics. thus critical factors corresponding to experimental results are introduced

    在簡要評述現有電流變效應模型及機理的基礎上,按非均勻介質對雙相復合懸浮液的電流變效應進行理論分析,研究了電流變效應頻率誘導特性;基於復合系統滲透壓的計算,採用統計熱力學唯象理論,討論了電流變效應的相分離特徵,獲得了與實驗吻合的臨界參數;首次將定向滲流模型應用於電流變體臨界體積濃度的分析,得出一個描述電流變流體特徵而不隨外加電場變化的臨界體積百分數為0 . 37 。
  17. This paper introduces the principle of phase - locked loop and analyzes the performance characteristics of pll chip adf4106 which has wide bandwidth and low power consumption. and then introduces the design method of a kind of low phase noise frequency synthesizers which uses single chip processor to control the chip. the application supplies a good design method for high frequency synthesizer

    介紹了鎖相環路的工作原理,分析了低功耗寬帶集成鎖相環晶元adf4106的工作特性,並介紹了一種利用單片機控制該晶元的低相位噪聲頻率合成器的設計方法,討論了環路濾波器的設計,為高頻頻率合成器的設計提供了很好的思路。
  18. Then, the frequency - hop system is presented. emphasis is placed on the analysis of effect on the phase modulation system which is produced in frequency - hop transmission. at last, we scheme out the fh - mpsk and fh - / 4dqpsk systems according to the frequency - hop communication characteristics

    首先介紹了跳頻通信的通道特性,然後說明了跳頻系統的工作情況,並分析了跳頻傳輸對相位調制系統設計的影響,最後針對跳頻通信的特點設計出跳頻傳輸模式下的fh - mpsk和fh - 4dqpsk系統。
  19. Realizing the impact of chirp on the effect of carrier phase, some analytical expressions of chirped few - cycle pulses are also calculated, such as frequency gravity, pulse energy, center of gravity of time, effective pulse width, etc. results show that chirp makes the pulse characteristics more sensible to carrier phase, and chirp has greatly increased the pulse width when the carrier phase takes effect

    考慮到啁啾對載波相位作用程度的影響,導出了啁啾脈沖的頻率重心、脈沖攜帶的能量、脈沖時間重心以及有效寬度等參量的解析表達式,分析表明,啁啾使得載波相位比無啁啾的情況提前起作用了,即啁啾在很大程度上增大了載波相位發揮作用所對應的脈寬范圍。
  20. The small - signal model in main circuit are built by using average circuit model. the relationship of each small signal and efficiency duty cycle are described completely. magnitude - frequency characteristics and phase - frequency characteristics of each main transfer function are got

    本文分析了全橋移相zvspwmdc - dc變換器的基本原理,運用平均等效電路法建立了主電路小信號模型,並詳細分析了各小信號變量與有效占空比之間的關系,得到了各主要傳遞函數的幅度和相位頻率特性。
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