預調頻率 的英文怎麼說
中文拼音 [yùdiàobīnlǜ]
預調頻率
英文
preset frequency-
Intermodulation suppression for fh ( frequency hopping ) receiver is designed by selecting the intermediate frequencies and changing group of filters, local oscillation ( lo ) frequency, bandwidth of lo frequency under the condition that receiver configuration, sensitivity, dynamic range, instantaneous bandwidth and precision of frequency measurement are fixed
摘要針對跳頻接收機的體制和靈敏度、動態范圍、瞬時工作帶寬、測頻精度等設計參數,通過改變預選器組成、本振頻率和本振帶寬,分析接收通道的中頻選取原則,以實現跳頻接收機的互調抑制設計。The basic principle, main properties, typical parameters, technical characteristics and general situation of klystron are introduced. the electron beam prebunching in the modulated cavity and shift tube of relativistic klystron amplifer ( rka ) is studied analytically, a self - consistent equation of radiation generated by the prebunched electron beam in the radiation cavity is derived using the field method of particle ? wave interaction instead of the electrical circuit method, and in terms of it, the gain in the linear regime calculated, a field analysis method is proposed. the theory analysis shows that the characteristic parameters, such as resonance frequency, real part of gap - impedance, external quality fadtor in all kinds of klystron output circuits including single - beam, multi - beam, single - gap, multi - gap, single - beammulti - gap, multi - beam multi - gap klystron output circuit, can be calculated by the field analysis method
本文系統的介紹了速調管的工作原理、主要特點、發展概況、主要性能指標和技術特點,解析的研究了電子束在相對論速調管放大器的調制腔和漂移管中的預群聚;用粒子波互作用的場方法導出了在輻射腔中預群聚電子束產生輻射的自洽方程,同時對線性區的增益進行了計算。理論分析表明,場分析法可用於計算單注單間隙、多注多間隙、單注多間隙和多注多間隙速調管輸出迴路的諧振頻率、間隙阻抗實部和外觀品質因數等特性參數。The main parameter are : the mean power of 45kw, the highest output voltage of 400v, the maximum output current of 50ka, the maximum repetitive rate of 100 hz, the preliminary charging time of 35s
裝置的主要參數為:平均功率45kw ,最高輸出電壓400v ,最大輸出電流50ka ,重復頻率1 100hz連續可調,預充電時間35秒。In case of absence of a precision external reference, the ocxo frequency adjustment is carried out by means of the p1 potentiometer
萬一一個精密度的外部參數預設, ocxo頻率調整依靠p1電位計來實行。The system is based on chopper constant current drive technique, according to the top level design idea, adopting advanced specical subdivision control integrate circuit and powerful function 80c196kc to organize the system frame, desiging the minimum system of single - chip microcomputer, multifunction i / o interface circuit, relay switch circuit, keyboard and display circuit, multifunction digital setting interface circuit and so on, utilizing the hso and hsi interface circuit which are owned by this single - chip microcomputer exclusively and its powerful command system to realize dual - degree switch control, automation orientation, automatically searching zero position, locking machine when stopping, frequency to set digitally, automatically adjusting speed through changing frequency, swithing subdivision or squarewave control, on the basis of above, the system also have the function of running according to the setting steps and the frequency, voltage and current to display through the led, etc
系統基於斬波恆流驅動技術,按照頂層設計思想,採用先進的專用細分控制電路和功能強大的80c196kc單片機來組建系統構架,設計了單片機最小系統、多功能i o介面電路、繼電器切換電路、鍵盤顯示電路和多功能數字設定介面電路等,利用該單片機獨有的hso和hsi介面及其強大的指令系統,實現了雙余度混合式步進電動機的余度切換控制、自動定位、零位自動搜索、停機鎖定、數字化頻率設定、自動調頻變速控制、細分方波切換控制,在此基礎上,該系統還設有按預置步運行、 led頻率電壓相電流顯示等功能。By choosing flood control system of downstream basin of the yellow river as the background, six relatively independent subsystem is established, which includes basic information management, real - time flood forecast, multi - reservoir flood control scheduling, consultation and analysis, scheduling scheme management, frequency analysis, and assist with friendly man - machine conversation to constitutes the yellow river downstream flood control scheduling decision support system, which can satisfy the practicability requirements of decision - making
論文以黃河下游防洪系統為背景,建立包括基本信息管理、短期洪水預報、水庫(群)防洪調度、會商與靈敏度分析、方案管理、水雨情頻率分析等6個相對獨立的子系統,並輔以友好的人機交互界面集成為黃河下游防洪調度決策支持系統,滿足了群決策會商的實用性要求。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。The voltage - controlled oscillator and the dual - modulus prescaler are the most crucial blocks in the pll frequency synthesizer. two kinds of voltage - controlled oscillator ( the quadrature voltage - controlled oscillator based on symmetrical spiral inductors and differential varactors, and the voltage - controlled oscillator with wide tuning range based on mos varactors ) and two kinds of prescaler ( the prescaler using phase - switching techniques, and the prescaler using dynamic circuit techniques ) are proposed. then, the complete pll frequency synthesizer is implemented, in which
壓控振蕩器和雙模預分頻器是鎖相環型頻率合成器中最關鍵的兩個模塊,本論文分別實現了兩種類型的壓控振蕩器(採用對稱螺旋型電感和差分二極體型容抗管的正交壓控振蕩器和使用mos型容抗管的大調諧范圍壓控振蕩器)和兩種類型的雙模預分頻器(使用相位開關技術的雙模預分頻器和使用動態電路技術的雙模預分頻器) 。Considering the nonlinear difference of the gain and phase characteristic in solid state power amplifier ( sspa ), a parallel but imbalanced predistorting adjuster is used and the hardware cost can be reduced
考慮到固態功率放大器( sspa )幅度和相位非線性特性的差異,該系統採用幅度和相位不平衡調節的射頻預失真結構,降低了硬體成本。The inverter apparatus controlled by pre - set voltage adjustment project has the advantages of low harmonic content, high output frequency precision, simple control circuit. therefore, this kind of project is the hot point in inverter power studying field
用「開關預置式電壓調節方案」控制的逆變電源具有輸出諧波含量低、輸出頻率精度高、控制電路簡單等優點,是逆變電源研究領域的熱點。The system reached control goal by experimental verification and the experimental results showed the system could produce ac excitation voltage with low harmonic, quick adjusting speed, wide adjusting range and high control precision of frequency
整個系統通過全面的實驗驗證,實驗結果充分說明所設計的系統產生出低諧波、調節速度快、調節范圍寬和頻率控制精度高的交流勵磁電壓,達到了預期的目標。This paper had did the most important work was the design of transciever and the construction of working environment, and also the video module and power amplifier module. at last, we did the measurement and debugging of total system, achieved anticipate target, satisfied the requirement of communication
本文所做的主要工作在於發射機總體設計和工作環境的構建,發射機視頻模塊,調制模塊以及功率放大器模塊的設計,最後對系統進行了總體的調試,達到預期指標,滿足了要求。The dynamic bit rate allocation module receives relevant data from the loss rate of multi - media data packet, jitter, delay, and compares these data with predefined values to make one of these 3 decisions that : decrease the video bit rate ( stat = decrease ), or maintain current video bit rate ( stat = hold ), or increase video bit rate ( stat = inccease ). the video bit rate will be adjusted according to the decision and the total bit rate is changed accordingly. in this way the impact of network environmental variation is settled, and consequently the adaptability of videoconference systems in remote education area is improved
整個模型從rtcp協議獲得多媒體數據包丟失率( lossrate ) 、抖動( jitter ) 、延時( delay )的相關數據,這些數據與預先設定好的閥值作比較,得出減小視頻位速率( stat = dectease ) 、維持視頻位速率不變( stat = hold )或增大視頻位速率( stat = increase )的決定,模塊根據這些決定對視頻位速率進行相應的調整,從而總的位速率也相應變化,這樣可以減小由於網路環境變化而帶來的影響,從而提高視頻會議在遠程教育應用中的實用性。We chose suitable tcp throughput model to estimate the available bandwidth correctly, using the estimated round trip time and packet loss ratio for the next time interval as parameters of the model to achive the accuracy of estimated network bandwidth. as the observed losses and round trip time vary very dynamically, adjust the sending rate equivalent to the amount of tcp throughput may result in a rather fluctuant sending rate. so we present a rate adjustment like tcp congestion control based on aimd, which increases its sending rate by an additive inereease rate
根據mpeg4視頻流應用的特點,選擇合適的吞吐量模型,進行合理的參數估計,並根據計算出的帶寬進行相應的速率調整來實現擁塞控制,我們使用未來rtt的估計值和分組丟失率的估計值作為吞吐量模型的參數,增強了控制的實時性,弱化了業務的振蕩性,提高了帶寬預測的準確性;在進行速率調整時,不是簡單地將發送速率調整到與tcp吞吐量模型一致,而是採用類似tcp的aimd策略來調節發送速率,減小了發送速率的振蕩性。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。Because quasi - fermi levels of a laser diode ( ld ) vary with the carrier density, it is predicted that a new type of hysteresis loop should occur for the current passing ld while a hysteresis loop appears on the power - frequency curve of the ecld. an explicit analytical expression for the frequency width of the hysteresis loop and the condition for the formation of the hysreresis loop has been deduced
預測了由於半導體激光二極體( ld )的準費米能級之差隨ld內線流子密度的變化而變化,因而,在調諧外腔半導體激光器的輸出功率?振蕩頻率曲線上出現雙穩環的時候,通過ld的電流也應出現一個伴隨的新型雙穩環? ?電流雙穩環。分享友人