narrow band 中文意思是什麼

narrow band 解釋
小差距匯率幅度
  • narrow : adj 1 狹 窄 狹隘的 狹小的 (opp broad wide)。2 有限的 受限制的;有偏見的 氣量小的 心眼兒窄的;眼...
  • band : n 1 帶,繩;帶形物;箍;箍條;嵌條;鑲邊;鋸條; 〈pl 〉 (法官等的)寬領帶。2 束縛,羈絆;義務;...
  1. Narrow band saw blades for woodworking ; dimensions

    木材加工用窄帶鋸片.尺寸
  2. Light visible to human eyes however occupies only a very narrow band in the whole electromagnetic spectrum

    然而,人眼可見的光在整個光譜中只佔一個非常狹窄的頻段。
  3. Nothing can embellish a beautiful face more than a narrow band drawn over the brow.

    除了一條橫束額上的細帶而外,沒有別的東西能把美麗的面龐襯托得更好的了。
  4. A jet stream is a narrow band of strong winds several kilometres above ground

    高空急流是距離地面數公里高的狹窄強風帶。
  5. Two kinds of filters are presented : by transferring the conventional waveguide cavity filter to the siw, a narrow bandstop filter is designed and simulated, get characteristic of narrow - band bandstop filtering. for example, relative bandwidth 1. 2 %, most attenuation of 48db in band. electromagnetic bandgap ( ebg ) structures present “ forbidden band ” characteristics, siw features high - pass characteristics, so bandpass filters can be composed by combing ebg and siw

    本論文提出了兩種基片集成波導濾波器結構:將傳統的腔體濾波器概念運用於基片集成波導結構,設計出了一種窄帶帶阻濾波器,對其進行模擬,得到了窄帶帶阻濾波特性,如相對帶寬為1 . 2 % ,最大衰減為48db 。
  6. The holographic lens, which is designed according to bragg condition to eliminate aberrations, has both high efficiency and low aberration, and can be used in a certain narrow - band condition. a example and its results are also given in this paper

    該方法採用雙片離軸全息透鏡復合,按使用條件在布喇格條件下進行消三級像差設計,製作設計的全息透鏡具有高衍射效率高、像差小的特點,可以滿足任意給定的窄帶光場合。
  7. Firstly, this paper introduces the basic structure of narrow band fir digital filters. secondly, it analyses the components of narrow band fir digital filters, which conclude cic filter, hbf filter, resampling techniques. based on these analyses, the paper gives the full structure of narrow band fir digital filters and analyses its characteristics, which are frequencies response, anti _ aliasing and anti _ image

    本文首先簡單介紹了窄帶fir濾波器的基本結構,然後對窄帶fir濾波器的各組成部分進行了詳細分析,內容包括:積分梳狀濾波器( cic )的特性和設計,半帶濾波器( hbf )和整形濾波器的特性和設計,重采樣技術的原理與實現。
  8. From the result we get the following conclusion : for narrow - band signal, the effect of the method based on fft is best. for wide - band signal, when snr is up to certain degree ( higher than - 7db or so ), the curves of square error of modified methods are more obvious and closer to crb. for an echo composed of more than one frequency or direction, space - frequency distribution could show more direct information of frequency and direction, which is more advantaged to make precise judge and estimation for doa of echo

    從估計結果發現,對于窄帶回波信號,基於fft的方法估計性能大大優于其他方法;對于寬帶回波信號,在信噪比達到一定程度(高於約- 7db )時,補償后的幾種估計法的性能改善均比較明顯,誤差曲線越來越接近crb曲線;對于回波中存在多頻率多方位的情況,空間?頻率分布圖能提供較為直觀的頻率及方位信息,因此應用空間?頻率估計法來進行方位估計,更有利於進一步對回波的具體方位進行準確判斷和估計。
  9. At first some modification is made in conventional beam forming of frequency domain, namely to estimate doa by arrays outputs on compensated spacial frequency points of echoes. then the cwt is utilized to signal processing in space - frequency domain for estimation of doa, and the corresponding modification is also made. in the dissertation, the computer simulations of doa estimation for both narrow - band and wide - band echoes are given, so do the necessary comparison among several methods and crb

    首先在傳統的頻域波束形成演算法的基礎上,提出對寬帶信號的頻率補償,也即對寬帶回波信號的各空間頻率根據時間頻率的差異進行相應補償,然後對各陣元輸出求和來得到方位估計;其次將連續小波變換引入到空間?頻率處理中,從而完成對目標方位的估計,並進行了相應地補償。
  10. Vacuum thin - film and dip coating services for optics. specializes in anti - reflective wide and narrow band for plastics

    -生產濾光片分光鏡增透膜紅外薄膜
  11. Pll has the excellent narrow - band - tracking - filtering characteristic. in this scheme, we combine the merits of dds and pll

    該方案是將dds的高解析度、高精確度、頻率變化易於控制的優點與pll良好的窄帶跟蹤性能相結合。
  12. Because period narrow band signals are the main part of background noises, this thesis uses hardware description language to design a multi - band finite impulse response filter ( fir ) and downloads the program into filed programmable gate array to eliminate the period narrow - band interferences in the background noises

    3 )在現場環境中,背景干擾主要是周期性的窄帶,本文利用硬體描述語言( vhdl )設計了一個多帶fir有限沖擊響應濾波器。應用到可編程邏輯器件中,消除了背景噪聲中的周期性干擾,為信號的進一步處理提供盡可能幹凈的信號。
  13. A novel communication receiver which uses lapped transform ( lt ) incorporating modified median filter ( mmf ) algorithm is designed for narrow - band interference excision. the lt domain mmf algorithm takes full advantages of the direct sequence spread spectrum signal, as well as the characteristics of lt, performing the transform domain filtering twice. the first filtering locates the position of interference and mitigates most of them. the second filtering is performed in a small neighborhood of the located interference. so lt domain mmf algorithm can completely mitigate the interference without distorting the desired signal. simulation results demonstrate the improved ber performance and increased robustness of our receiver

    本文採用改進的重疊變換域中值濾波演算法進行變換域抗干擾處理.該演算法既考慮到直接序列擴頻信號的特點,同時又利用重疊變換的特性對變換域系數進行了二次濾波.該演算法節省處理時間,並且不需要有關干擾的先驗知識,系統性能不會隨干擾頻率變化而變化,因而是一種很穩健的處理方法
  14. 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。
  15. 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。
  16. 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。
  17. Experiments show that, when use msp430f149 audio sensor to identify vehicles that contain plane, tank, truck and so on by time domain features and two - level f - ratio, the recognition rate is 82. 1 % ; when use both msp430f149 audio sensor and arm9 sensor to identify vehicles, and the recognition rate is much better than the original system and msp430f149 audio sensor. line spectrum of power spectra and 3 / 2 spectrum is used as frequency features on arm9 sensor, and it is caught by narrow - band bandpass filter

    實驗證明,在主頻為8mhz的msp430f149感知器上,採用基於時域特徵和二階f比的識別演算法,能夠實時地完成對飛機、坦克、卡車等交通工具的識別;將msp430f149感知器與基於arm9的高端感知器配合使用,且高端感知器採用功率譜線譜或3 / 2維譜線譜作為頻域識別特徵,能夠實時的對各類交通工具做更高性能的識別。
  18. Narrow band amplifiers power amplifiers

    檢波對數視頻放大器dlav
  19. Narrow - band filter

    窄帶濾片
  20. Road vehicles - electrical disturbances by narrow - band radiated electromagnetic energy ; vehicle test methods - part 1 : general and definitions iso 11451 - 1 : 1995 technical corrigendum 1 : 1996

    道路車輛.窄帶輻射電磁能量電氣干擾.車輛試驗方法.第
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