high frequency band 中文意思是什麼
high frequency band
解釋
高頻段-
In the next place, by studying the change of the resonant frequency of the whole system, this paper designs the circuit to track the resonant frequency of the system by cd4046 mainly. at the same time, in order to improve the efficiency and get better dynamic capability of the converter, we choose pll and fuzzy control after comparing the pll circuit, fuzzy circuit and pll ? fuzzy control circuit. in the end, this paper brings forward the control blue print to realize the drive control circuit of the high frequency converter, using the dsp chip as the key part to realize four routes of pwm drive pulses with dead band of the control system
其次，通過對整個系統諧振頻率變化的分析和研究，設計了以鎖相環cd4046為核心的鎖相環控制電路，同時，在綜合比較鎖相環控制、模糊控制以及模糊控制和鎖相環復合控制三種控制演算法的基礎上，進行了系統模擬，得出採用復合控制可使跟蹤電路既具有鎖相環路較好的穩態性能，又擁有模糊控制較好的動態性能，系統魯棒性能好，同時也提高了逆變器的效率。 -
Design of broadband shipboard whip - type antenna at high frequency band
艦用短波寬帶鞭狀天線研究 -
Mixers are the key components of many microwave and millimeter - wave systems. the super - heterodyne receiver is always applied in modern communication system, mixer becomes the key component as is at the first part of system. but it is more and more difficult to get the choiceness lo source of the same band with the system is working at high frequency especially in the millimeter - wave. sub - harmonic mixer is a good solution to this problem now. in this circuit we need just half 、 quarter 、 even 1 / 8 of the rf signal frequency. in this paper the design and fabricate of sub - harmonic hmic mixers ( 2, 4 ) at w - band are introduced
混頻器是微波通信、射電天文學、雷達、等離子物理、遙控、遙感、電子對抗，以及許多微波測量系統中至關重要的部件。在現代通信系統中，毫米波頻段通常採用超外差接收機，混頻器作為第一級就成為關鍵部件。由於在毫米波頻段，同頻段高性能的本振源成本高，技術難度大，採用分諧波混頻技術是解決此問題的有效途徑，只需射頻頻率1 / 2 、 1 / 4甚至1 / 8的本振頻率即可實現混頻。 -
With the rapid development of the semiconductor technology, large of the vacuum electronic device has replaced by the semiconductor element from the middle period of the last century. however, the vacuum electronic device owns tremendous prepotency in the exceed - high frequency and wide frequency band and high power field, especially in the exceed - high power field. the complexion won ’ t be changed for a long period
自上世紀中後期開始，隨著半導體技術的飛速發展，許多真空電子器件逐步被半導體器件取代，但是，在超高頻、寬頻帶、大功率，尤其是超大功率領域，真空電子器件在技術和經濟方面至今仍擁有巨大的優勢，而且在今後相當長的時期內，這種局面也不會改變。 -
In order to obtain the complex rcs of the target quickly in high frequency band, the graphical electromagnetic computing software, greco, is used. the modification of the computing kernel code is presented. the judgement of edges of complex targets is more sufficient and the computation of edge wave based on physical theory of diffraction ( ptd ) is more exact after the modification
為了可以準確地預估雷達目標的rcs ，我們對于航天部207所的圖形電磁計算軟體（ greco ）進行了進一步的開發與包裝，用borland公司的c + + builder開發了更加易於使用的基於windows操作系統的新版greco ，並且在考察了原有的greco計算內核之後，結合計算機圖形學方面的理論，對greco的內核代碼進行了改進，整體上使得邊緣繞射場的計算結果更加準確。 -
Characterized by wide band gap, high breakage electric field, high thermal conductivity, high saturated electron mobility, cubic silicon carbide ( 3c - sic ), considered as one of the most promising wide band gap semiconductors, is widely utilized in high temperature, high frequency and large power semiconductor devices
3c - sic被譽為最有潛力的寬禁帶半導體材料，具有帶隙寬、臨界擊穿電場高、熱導率高、飽和電子漂移速度大等優點，是高溫、高頻、高功率半導體器件的首選材料。 -
The merits of dds such as super fine frequency resdutlon 、 high frequency accuracy 、 easy programmed can be in combination with the excellent character of narrow - band tracing filter merits of pll
它可以將dds的超高頻率解析度、高頻率精確度、容易實現程式控制等優點與鎖相環良好的窄帶跟蹤濾波特性相結合。 -
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。 -
In this system two oscillator are used for mixing. pll for high local oscillator and dds + pll for low local oscillator. 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
系統採用兩次混頻，其中高本振的設計採用pll鎖相環頻率合成來實現，充分發揮了鎖相環頻率合成器的優良特性，實現了系統所要求的高質量寬頻帶本振源；低本振採用pll + dds頻率合成來實現，結合pll優良的鎖相特性與dds的高頻率解析度、高頻率精確度等優點，實現了頻率的小步進高精度合成。 -
A high efficiency dual - band rf power amplifier has an output and / or input of a high frequency transistor well terminated at the second harmonic frequency for dual - band operation
本發明乃一種高效率雙頻射頻功率放大器，提供高頻電晶體的輸出端與?或輸入端于雙頻操作中有良好的二階諧波終止。 -
Employing the interlaced scanning, current tv system can compress the frequency band of tv signal effectively and facilitate transmission. but this method reduces the scanning lines of pictures and the frequency of the field. it leads the pictures displayed on tv to have such disadvantages as large area flicker, edge flicker, interlace flicker, raster visibility and creeping line etc. to satisfy people " s vision feeling better, the big - screen, multi - function and high quality tv - set have been made great progress
現行的廣播電視系統由於採用隔行掃描方式，從而有效地壓縮了電視信號的頻帶，有利於傳輸；但由於這種方式使得圖像的掃描行數少，場頻低，導致了重顯的電視圖像有大面積閃爍、邊緣閃爍、行間閃爍、行結構可見及行爬行等。 -
The research result demonstrates that along with the increment of reynolds number, the root mean square value of outer fluctuating magnitude of the external diameter in fall frequency band increases, the root mean square value of fluctuating magnitude of the external diameter in high frequency band decreses, demonstrating that the fluctuation of flexible pipe wall changes fluctuation don field of original rigid pipe, large - size eddy motion increases and small - size eddy motion decreases, this reduces energy loss and increases friction reduction effectiveness
研究結果表明：隨著雷諾數的增加，全頻帶的外徑脈動的均方根值加大，但高頻帶外徑脈動的均方根值減小，說明柔性管管壁脈動確實改變了原剛性管的脈動流場，大尺度渦的運動加劇，低尺度渦運動減弱，從而使得能量損失減少，減阻效果增大。 -
The thesis introduces the definition of transient current and it ' s energy. the tranvelling wave can be affected by power system equipment, it ' s effect is analysed with energy change of transient current at high frequency band
討論分析了電力設備對行波的影響。提出了通過暫態電流高頻分量的能量及其能量比值變化情況定量分析變電站設備對暫態電流高頻分量的影響程度的方法。 -
Over - the - horizon radar ’ s beam - frequency is high frequency band and its wavelength is so long that the annate ’ s characters are very complicated when applicated on the ship. the character of coupling between cells and the environment must be measured to compensate in the radar signal process step. the ship - based over - the - horizon radar uses cfa ( crossed field antenna ) as array antennas ’ cell
艦載超視距雷達使用高頻信號作為發射頻率，其波長較長，在艦船有限的空間內，陣列天線的陣元之間的耦合與陣元與背景之間耦合都十分嚴重，必須測量陣列天線通道的幅相一致性，作為雷達信號處理的補償參數。 -
The data regression processing method based on fuzzy mathematics theory is proposed to get the middle frequency band simulating result based on finite element result of low frequency band and statistics energy analysis result of high frequency band to get a complete frequency band result and solve the middle frequency band result processing problem in the simulation of floating raft isolation system
摘要為了解決浮筏隔振系統模擬結果的中間頻段數據處理問題，基於浮筏隔振系統低頻段的有限元分析結果和高頻段的統計能量分析結果與試驗結果的對比分析，提出採用模糊理論進行數據回歸處理來得到中間頻段的模擬結果，從而提出一種估算浮筏隔振效果的方法。 -
The development of filters, resonators and other telecommunication technology required better dielectric materials. the dielectric materials, used as the resonate body, should be high in dielectric constant, low in dielectric loss and a near zero temperature coefficient of dielectric constant in high frequency band, also could be sintered in a relative low temperature so as to reduce production cost, and what ’ s more, the miniaturization and reliability of materials are also the main aspects in the research work of high frequency band dielectric materials
隨著濾波器、諧振器等器件以及通信技術的發展，人們對電介質材料的要求越來越高，要求作為介質諧振腔的電介質材料在高頻段下具有高介電常數，低介電損耗，接近於零的介電常數溫度系數，還要求高頻電介質材料能夠在較低的燒結溫度下燒成，以降低實際生產的成本，此外，材料的小型化，高可靠性也是高技術高頻介質材料的重要研究方向。 -
As for frequency domain, tirls includes mainly 3 frequency bands : ( 1 ) high frequency band with period less than 1 year, which is relative to weather ; ( 2 ) mid frequency band with predominant period 1 year, relative to sun, plant and season ; ( 3 ) low frequency band with period more than 1 year, relative to the crustal activity and long period variation of atmosphere temperature
從頻率域看，地表熱紅外輻射主要存在3種頻段： （ l ）高頻，周期小於1年的天氣變化； （ 2 ）中頻，以1年周期為主的太陽、植被與季節變化； （ 3 ）低頻，大於1年周期的大氣變化的長周期成份，地殼緩慢的運動引起的熱輻射變化亦屬于長周期變化。 -
Very - high frequency band
甚高頻頻帶 -
Utilizing phase locked loop technique with complex programmable logic devices ( cpld ), a method to perform high - speed data acquisition, storage and transmission for transformer testing, which solves the problem of data acquisition for high frequency band, is proposed
摘要提出了利用鎖相環技術結合復雜可編程邏輯器件（ cpld ）實現對變壓器測試信號的高速採集、存儲、傳輸的方法，很好地解決了對變壓器高頻特性信號的採集。 -
Chapter 2 introduces the theory of frequency - hopping and omsk, at the same time gives out a fh - gmsk radio model in high frequency band under the matlab simulink environment. chapter 3 respectively proposes the parameter blind estimation algorithms for high - speed - hop and low - speed - hop fh signals based on smoothed pseudo wvd ( spwvd ). furthermore, the simulation results are given to demonstrate the algorithms performance
第三章用「平滑偽wvd （ spwvd ） 」時頻分析技術分別研究了對高速跳和低速跳的跳頻信號的參數盲估計演算法，並對這兩種演算法，分別在matlab的環境下做了模擬和性能分析。
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