寬頻帶作用 的英文怎麼說
中文拼音 [kuānbīndàizuòyòng]
寬頻帶作用
英文
broadband operation-
Based on the real situation of submarine and antisubmarine warfare ( asw ), according to the classical design theory of transducer or transducer array, a sonar will be researched and made, which has the feature of more wider bandwidth, more lower operating frequency, more lager radiation acoustic power, more farther operating distance, more higher researching efficiency and more higher directive accuracy
本文根據現代潛戰和反潛戰（ asw ）的實際情況，按照經典的換能器和基陣的設計理論，研製聲吶，旨在擴展其頻帶寬度、降低其工作頻率、增大其發射功率、擴大其作用距離以及提高其搜索效率和定向準確度。In all kinds of complicated network, oriented linking and unlinking, communication frequency resource is strained, and bandwith to transmitting audio frequency signal is too restricted, complicated and fluky, while audio frequency data exponential have been increased in the last several years. under the circumstances, based on the research of predecessor, this paper studies wavelet analysis ' s maths gist and practices significance on signal process, and puts forward a optimized wavelet package condensation arithmetic to process audio frequency data, which gives attention to coding efficiency, multirate and compression delay. simulation experiment on the arithmetic has been done by matlab
針對無連接和面向連接的各種復雜網路環境下，通信頻帶資源緊張，音頻傳輸帶寬有限且復雜多變，而各種音頻數據又日益增多的局面，本文研究小波分析在信號處理方面的數學依據和在數據壓縮方面的實際意義，在前人不斷工作的基礎上，提出了一種優化小波包變換編碼方案用於音頻數據的壓縮演算法，兼考慮了編碼效率、多碼率和壓縮時延多個方面，並在matlab環境下做了模擬實驗，對各種音頻信號及多種小波函數做了模擬結果比較，實驗結果證明該演算法可以在一定計算復雜度下可以很好地改進壓縮效果，達到多碼率下實現實時編解碼的過程，在高速dsp晶元等硬體設備支持下，可以有效應用於實際復雜多變信源編碼。The factors limiting the frequency band of the wide - band amplifier are introduced. through analyzing the effects of the intrinsic parameters and parasitical on the frequency characteristics, a method of improving fr of mosfet by using short channel device and making mosfet work at the saturation region through raising vgs is put forward ; the effects of different kinds of circuit configurations on the frequency characteristics and the junction voltage on the voltage pattern circuit, current pattern circuit and frequency characteristics are analyzed. according to the linear theory of transconductance which is applied in the bit circuit, the current pattern amplifier circuit, current transfer circuit and output circuit which consist of mosfet and the wide - band amplifier composed of them are put forward
介紹了限制寬帶放大器頻帶寬度的因素，通過分析mosfet的本徵參數、寄生參數對頻率特性的影響，提出了採用短溝器件、使mosfet工作在飽和區、抬高柵源電壓等提高mosfet特徵頻率的方法；分析了不同電路組態對放大器頻率特性的影響、節點電壓對電壓模電路、電流模電路頻率特性的不同影響，根據應用於雙極晶體管電路的跨導線性原理，提出了採用mosfet構成的電流模放大電路、電流傳輸電路、輸出電路以及由它們所組成的寬帶放大器，獲得了良好的頻率響應。Compare to the normal rectangular waveguide, ridge waveguide has the character of broader bandwidth, smaller dimension, lower equivalent characteristic impedance, etc. because of these merits, it is used more and more widely, such as broadband ridge waveguide filter, broadband direct coupler, diplexer, frequency converter, phase shifter, ridge waveguide slot antenna array, and so on
與普通矩形波導相比，脊波導具有工作頻帶寬、尺寸小、等效特性阻抗低等特點。由於脊波導本身的特點，使其得到了越來越多的應用，例如寬帶脊波導濾波器、寬帶定向耦合器、雙工器、變頻器、移相器、脊波導縫隙天線陣等等。The control tactics of space voltage vector are investigated, and the simplified algorithm which judges the sector location of reference vector and calculates switch operation time is put forward. by analyzing the current hysteresis control, the relation between switch frequency, and hysteresis bandwidth and input inductance of pwm rectifier is deduced. by applying instantaneous power theory, the principle of pwm rectifier power control is analyzed, and the direct power control by matlab toolbox through estimating active power and reactive power with virtual flux is realized, and the simulation results prove that it is correct
對常用空間電壓矢量控制策略進行分析，提出了給定參考矢量所在區間判斷的簡化方法，以及電壓矢量作用時間的求取方法；分析了電流滯環控制策略，推導出開關頻率與滯環帶寬以及整流器輸入電感之間的關系；應用瞬時功率理論分析pwm整流器功率控制原理，通過虛擬磁鏈估計有功功率和無功功率，用matlab實現了直接功率控制，並驗證了該控制方法的正確性。The future wireless mobile communication systems are expected to provide ubiquitous, high - quality, and high - rate mobile multimedia transmission. however, hostile multipath fading radio conditions give rise to serious inter - symbol interference ( isi ) ; even worse, wireless channel are often time varying, which makes the system more vulnerable and more difficult to track the channel state. orthogonal frequency dvision multiplexing ( ofdm ), which is inherently resistant against isi, has invoked a popular research interest in recent years, and has been a promising candidate technology of the physical layer for future weideband high - date - rate wireless communications. notwithstanding, ofdm is much more vulnerable to errors of both time and frequency synchronization and to that of channel estimation, and how to obtain correct timing and channel estimation efficiently is highly critical to ofdm systems. the dissertation will focus on both of the aspects of ofdm systems mentioned above
但是無線環境的多徑特性造成通信系統中嚴重的符號間干擾，同時無線通道的時變性使得通道特性跟蹤復雜。而正交頻分復用技術（ orthogonalfrequencydivisionmultiplexing ， ofdm ）正是一種解決符號間干擾的有效傳輸手段，因此ofdm技術作為未來寬帶高速率無線通信的物理層候選技術在當前引起了一股研究熱潮。但ofdm系統對定時同步誤差和通道估計誤差非常敏感，如何在ofdm系統中準確快速地實現符號同步和通道估計是至關重要的，本論文將重點針對這兩個問題進行討論。Pulse compression technique and large timeband product signals such as linear frequency modulation signals, nolinear frequency modulation signals, phase coded signals and so on are widely used in modern radar systems to improve the resolving power both in range and in speed domain
現代雷達為了提高雷達作用距離和速度分辨力、距離分辨力，廣泛採用了脈沖壓縮技術及大時寬帶脈壓信號如：線形調頻、非線形調頻、相位編碼信號等。We design the qmf based on the criteria of minimum frequency bandwidth and the qmf that possess linear phase, and give a example of a signal decomposed and restructured. 4. in the research of channel dropping filters, we use 5 rank butterworth filter to approach the digital filter. we design lc unpower netwok and rc power network. we manufacture lc lowpass and highpass filter ， and test their performance ; we simulate the appliance of the channel dropping filters in the system
4 .在頻帶分割濾波器的設計方法中，用5階巴特沃斯濾波器逼近最小頻寬正交鏡像濾波器，對無源和有源濾波器進行了模擬設計；設計並製作了無源lc低通和高通濾波器，測試了它們的性能；並對分割濾波器在系統中的應用進行了計算機模擬。Proposed by the european broadcasting union, eureka 147 is widely applied in europe, canada and part of asia. the technology operates in the new l - band or vhf band iii. its 1. 5 mhz bandwidth can accommodate a maximum of about 1. 2 mbps of data
Eureka147是現時歐洲廣播聯會（ europeanbroadcastingunion ）推廣的制式，被歐洲、加拿大和部份亞洲地區所採用，它的設計是需要另外在新的Ｌ頻帶或甚高頻帶vhfbandiii操作，頻寬1The circular monopole ultra - wideband antenna has not only the extremely wide band in frequency domain, but also stable phase center, which makes the antenna radiate and receive the short pulse signals without any distortion, and suitable for various ultra - wideband communication systems or the single antenna of other multi - frequency operating communication systems
這種天線不僅具有極寬的阻抗帶寬，還擁有穩定的相位中心。這使得圓盤單極超寬帶天線可以不失真地收發時域短脈沖信號。所以該天線不僅適用於超寬帶通信中，還能夠作為復雜多頻工作系統的單一收發天線。The application of multi - level delay charging method has change the conventional charging method and increase the effective energy in downgoing elastic wave, which has unique effect in increasing the bandwidth of effective wave, resolution, s / n ration and interference attenuation and is worth to propagate
多級延遲爆炸技術的應用，改變了傳統的激發方式，提高了彈性波下傳的有效能量，對提高有效波頻帶寬度、在提高解析度、信噪比、壓制干擾各方面，都具有獨特的作用，具有很好的推廣價值。Usually the frequency bandwidth of microstrip patch antenna is relatively narrow. however, it can be effectively broadened with the employment of the micro - electro - mechanism systems technique to fabricate microstrip antenna with multilayer dielectric substrates and patch
通常微帶貼片天線的頻帶較窄，而利用微電子機械繫統（ mems ）技術製作具有多層介質和貼片結構的微帶天線，可以有效地擴展天線的帶寬。The growth rate of inflectional instability and viscous instability also saturate similarly to the primary and nonlinearly generated disturbances. the main effect of inflectional instability mode in the final breakdown seems to interact with the disturbances having developed and thus widens the frequency spectrum to turbulent state
屬于拐點不穩定性的高頻二次不穩定模態對最後轉捩的影響主要體現在與其它擾動的相互作用，並導致出現紊流狀態寬帶頻譜。The low - frequency discrete noise of the propeller is induced by the interaction between blades of the propeller and wake of the marine, and the low - frequency broadband noise of the propeller is produced by the interaction of blades and turbulent field of the marine stern
螺旋槳的低頻離散譜噪聲是由船尾伴流場和葉片的相互作用引起的，而低頻寬帶噪聲是由船尾粘性湍流場和葉片的相互作用產生的。754 horizontal - component digital broad - band records in western north america are processed. the acceleration response spectra are calculated and used as part of the database. the response spectrum values are estimated by the earthquake magnitude definition and are used as another part of the database
將美國西部地區作為參考地區，對美國南加州地區的數字寬頻帶記錄進行了搜集與處理後作為觀測資料，共754條水平向記錄，與利用震級定義所估計的反應譜值一起，用統計回歸的方法建立美國西部長周期加速度反應譜衰減關系。5. otherwise, the applicability of cube comer array in the wide spectrum high power solid - state laser facility was researched as a relatively absolute part in this paper. through simulation, the action of cube corner array to reduce beam ' s focal spot size was testified visibly, and the smoothing effect of beam ' s modulation caused by cube corner array was proved primarily on the wide spectrum condition
另外，作為一部分相對獨立的內容，本文對寬頻帶激光傳輸條件下採用角錐棱鏡陣列抑制低頻波前畸變的設想進行了探索性的研究，通過模擬模擬驗證了角錐棱鏡陣列具有抑制低頻波前畸變、提高激光焦斑能量集中度的顯著作用，並初步驗證了寬頻帶激光傳輸條件下近場振幅高頻調制的勻滑效應。C60, a new type of semiconductor material, has many superior properties, such as wide forbidden band, direct band gap, rapid responding time, high optical damage threshold value and wide responding frequency band etc. these capabilities indicate that c60 film will be used widely in computer, integrate optical instrument and storage device etc. however, the preparation and the purification of c60 material affect the large - scale application at all times
C _ （ 60 ）薄膜作為新的半導體材料具備許多優越特性，如禁帶寬度大、直接帶隙、快速響應時間、高的光學損傷閥值、較寬的響應頻帶等，這些性能預示了c _ （ 60 ）薄膜在計算機、集成光學器件、光存儲器等方面具有廣闊的應用前景，但c _ （ 60 ）材料的制備與提純還一直是阻礙該新材料投入大規模實際應用的主要因素。The usual method to broaden the bandwidth of the pin diode switch is combining the pin diodes with stub filters : when under reverse bias, the didoe is part of the filter, the transmission bandwidth is broadened ; when under forward bias, the structure of the filter is destroyed, signal is isolated
Pin二極體開關展寬頻帶的方法一般是把pin二極體結合進短截線濾波器，使pin二極體在反向偏置時作為濾波器的組成部分，以展寬開關在傳輸狀態下的頻帶；當二極體正向偏置的時候，濾波器的結構被破壞，起到隔離的作用。This paper analyses crystal oscillator ’ s character and technique targets, and the changes of these technique targets effect the time of crystal oscillator gives the error mode of crystal oscillator time, by discussing gps system and time service theory, we analyze random character of gps second pulse error. we combine long - time stability of receiver ’ s output signal and short - term stability
該系統成功地應用於寬頻帶地震記錄儀中，使地震數據記錄的時基精度達到微秒級，可以解決大范圍的地震儀布設應用時的授時和空間定位（經度、緯度、海拔）問題，為地震數據記錄、分析工作提供了與國際標準時間同步的時間基準。On the other hand, the resolution of wavelet is adapted in time - frequency plane and the structure of wavelet transform is similar to that of wide - band correlation processing. so wavelet transform is an important tool in future underwater signal processing
小波變換具有在時頻平面內自適應調整單元解析度、與寬帶相關處理結構相似等優點，使得它在非平穩和寬頻帶信號處理中起著非常重要的作用。分享友人