頻率調制波 的英文怎麼說
中文拼音 [bīnlǜdiàozhìbō]
頻率調制波
英文
frequency-modulation wave- 頻 : Ⅰ形容詞(次數多) frequent Ⅱ副詞(屢次) frequently; repeatedly Ⅲ名詞1 [物理學] (物體每秒鐘振動...
- 率 : 率名詞(比值) rate; ratio; proportion
- 調 : Ⅰ動詞1 (配合得均勻合適) harmonize; suit well; fit in perfectly 2 (使配合得均勻合適) mix; adju...
- 制 : Ⅰ動詞1 (製造) make; manufacture 2 (擬訂; 規定) draw up; establish 3 (用強力約束; 限定; 管束...
- 波 : Ⅰ名詞1 (波浪) wave 2 [物理學] (振動傳播的過程) wave 3 (意外變化) an unexpected turn of even...
- 頻率 : frequency; rate
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In designing analogic circuit, we adopt programmable filter max262 to meet the system ' s command. after the step, we can make the signal ' s frequency width is wider and noise level is lower. to make the signal ' s amplitude to meet the analogic to digital device ' s command, we adopt the max551 to finish the gain control
在模擬電路部分,採用可編程濾波器max262 ,這樣就滿足了該數據採集裝置所採集的信號的頻率范圍較寬以及具有較低的噪聲水平的要求,為了使采樣到的信號的幅度滿足後面a d轉換器的要求,採用max551對采樣到的信號進行調理(增益控制) 。The 1mhz fixed frequency switching allows for tiny external components and the regulation scheme is optimized to ensure low emi and low input ripple. an external resistor sets the full - scale led current, while two digital inputs control on / off and select amongst three levels of brightness. the circuit operates in 1x mode until just above dropout
工作在1mhz固定頻率,採用線性調制模式使輸入紋波大大減小;利用一個外部電阻可以設置滿量程led電流;外接兩個數字信號控制晶元開關並選擇led三級亮度中的一級;具有過溫、過壓/欠壓等保護功能,工作溫度范圍為- 40 + 85 。Secondly, according to the character of this kind of harmonic, the solutions of power filter are deeply analyzed and an optimized topology for series connected hybrid power filter is obtained. by pwm technique, midfrequency transformer and the principle of the magnetomotive force ( mmf ) compensation, the problem to the transfer of the low - frequency harmonic power compensatory signal in the series apf is solved, in technique
其次,針對acem系統特有的「電源諧波」特性,深入分析了濾波器方案,得到了一種適用於acem系統諧波抑制的串聯混合型有源電力濾波器優化拓撲結構,並採用了pwm調制技術、中頻注入變壓器和磁勢補償原理有效地解決了串聯apf中低頻諧波功率補償信號傳輸的難題。In this thesis, firstly, we put forward a new algorithm of the synchronization of carrier reference phase, that is to use the curve synthesizing with the general digital carrier phase looper to have an estimation on carrier frequency within 10 ms so as to meet the need of meteor burst communication. we have done some simulations to get the performance of carrier frequency estimation using two modulation modes ( 16qam and 4 - qpsk ), and had some test on the carrier phase looper in conditions when using different baud rate transmission and when the baud tuning have windage
我們對兩種正交調制方式( 16qam和4 - qpsk )進行了模擬工作並給出了模擬結果,同時討論了碼元同步定時誤差對鎖相環路工作的影響並根據流星通信中使用變速率傳輸時鎖相環路的載波同步性能進行了測試;然後在基於軟體無線電思想的數字處理平臺(該數字處理平臺實現了中頻數字化)上用dsp軟體完成了載波的相位跟蹤。The research on carrier spectrum, modulation schemes and signal codes of plc networks has received much attention, while the mac protocol of plc networks is usually adopted from general - media computer networks
目前國際上注重研究plc網路的載波頻率、調制方式、信號編碼等關鍵技術。而對于plc網路的mac協議,卻通常採用修改的常規計算機網路的mac協議。However, the efficiency of pwm at light load is low and the filter design of pfm is rather difficult due to the random characteristic of the frequency spectrum distribution
採用相應調制方式的ic品種繁多,各有千秋。但pwm在輕載時效率較低,而pfm由於頻譜分佈隨機,不利於后續濾波器的設計。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。( 8 ) by studying match between the electronic system and catalytic converter on the base of electronic controlled bypassing air system, conclusions having been gotten as follows : higher conversion efficiency of emission have gotten when a / f fluctuates at definite scope and frequency, by controlling the comparing voltage of 02 sensor, the working scope of catalytic converter can be controlled and the matching that can fulfill the high efficiency of hc, co, nox at same time has been optimized
( 8 )進行基於所開發的電控補氣系統上的催化器與電控系統的匹配研究,當控制系統調節空燃比在一定范圍按照一定頻率進行波動時,可以提高催化轉化器的轉化效率;通過控制氧傳感器的比較電壓,可以控制催化轉化器的工作窗口,實現排放污染物中, hc 、 co 、 nox轉化的最優匹配。Fpga and dvb standard are introduced firstly, dvb - c standard and composition of its system are analyzed completely, development of modulator structure and dvb - c digital modulator composition are presented, more over, analysis of respective modular are given. then, principle of dvb - c digital modulator system are presented, they are error control technique 、 mqam 、 nyquist rule and root raised cosine filter 、 window design method for fir filter 、 multi - rate signal processing ( integer interpolating, conversion of fractional sampling, equal conversion of net structure, polyphase structure for filter, poly - phase structure for interpolator, multi - stage implementation of samplying conversion ) 、 distrubited algorithm 、 cic filter 、 dds 、 cordic algorithm
接著,專門利用一個章節闡述了dvb - c前端調制系統原理,他們了差錯控制技術、多進制調制( mqam ) 、 nyquist準則與平方根升餘弦濾波器、有限沖擊響應濾波器的窗函數設計法、多抽樣率信號處理包括(整數倍內插原理、分數倍抽樣率轉換、網路結構的等效結構、濾波器的多相表示、內插器的多相表示、抽樣率轉換的多級實現) 、分散式演算法、 cic濾波器、直接數字頻率合成( dds ) 、 cordic演算法。1 m 0. 5, the phase - shifted angle 6 is controlled in term of sine law which makes the magnitude of resonant voltage track a reference sine voltage, and the resonant voltage is rectified, filtered, inverted and then the better sine - voltage output is obtained, theoretical analysis and experimental results show that for the resistive load and inductive load, the switches of leading leg of the phase - shift - controlled circuit are always turned on at zvs, and ones of lagging leg are turned on at zvs ( < 0 ) or turned off at zcs ( ( > 0 ), moreover, all switches in the low - frequency inverter are always turned on and off at zvs, the measured circuit efficiency for rated load reaches up to 88 %
從功率單向流動角度出發,提出了一種lcc諧振型恆頻移相單相高頻鏈逆變電路拓撲,在調制系數0 . 1 m 0 . 5情況下,控制移相角按正弦規律變化,使諧振電壓脈沖列的幅值追蹤參考正弦電壓信號,經過整流、濾波、低頻逆變,從而獲得正弦度較好的輸出電壓。理論分析和實驗結果證明對于阻性負載或阻感性負載,移相全橋具有超前橋臂零電壓開通,滯后橋臂或者零電壓開通( _ 0 )或者零電流關斷( _ 0 )的軟開關特性,而低頻逆變器的各個開關均實現零電壓條件下的開通與關斷。Water dielectric pulse power modulator has been widely applied because of its merits of high energy storage density, compactness, and capability to drive low impedance high power microwave sources. research for multi - pulse operation of high power spark gap switch with high current and comprehending its physical properties are the basis to study multi - pulse operation or repetitive operation of water dielectric pulse power modulator
水介質脈沖功率調制器具有儲能密度高,結構緊湊、與低阻抗微波源較好匹配的特點,因此得到廣泛的應用,但是受到高功率、大電流氣體開關的絕緣恢復的影響,水介質等低阻抗脈沖功率調制器的重復頻率運行或多脈沖運行受到較大的限制。In order to increase processing rate of inserting filters, pipe line is used to satisfy if ( intermediate frequency ) modulation. 5. nco ( numeric controlling oscillator ) based on lab ( look - at table ) fully satisfy if modulation
研究了級聯內插濾波器在寬帶if調制中的應用;以及如何加流水線( pipeline )提高內插濾波器的處理速率,滿足高速中頻( if )調制要求。For digital audio encoding and decoding modules, delta - sigma modulation is introduced and audio data, preambles with accessorial data are multiplexed according to the digital audio interface standard ; for carrier wave, pll frequency synthesizer is used ; for frequency modulation, voltage control oscillator is taken ; for demodulation, pll frequency discrimination is adopted
調制方式,並按照數字音頻介面標準對音頻數據、同步字和附加信息進行通道復用;對于載波信號,採取鎖相環頻率合成技術手段;對于頻率調制,採用壓控振蕩器;對于解調電路,採取鎖相環鑒頻電路。Transmition velocity relys on the style of encode and modulation essentially during modern data transmition for the quality of using line bandwidth and the immunity of code ties on them tightly. but it is important that the velocity of data transmition reaches its limitation in fact for the interface of environment and cross - talk. so for the improvement of transmition velocity, we must analyze the characteristics of noise signal and the model of line deeply and then take some useful measures to better the immunity of modulation wave
在現代通信的數據傳輸過程中,傳輸速率本質上是由傳輸的編碼方式和調制方式決定的,因為編碼方式和調制方式直接決定了線路頻帶利用率和碼元抗干擾能力的好壞,因而直接決定了傳輸速率;但是在實際應用過程中,數據傳輸速率是不可能達到理想狀況的,因為環境干擾、串音干擾等因素的存在使得線路的頻帶不可能被完全利用起來;因此,必須認真分析線路的噪聲信號的特性以及噪聲線路的模型,以便在編碼方式和調制方式中針對性的做一些改進措施以改善調制波形的抗干擾能力,使得傳輸速率能夠進一步提高。Lfmcw ( linear frequency modulation continuous wave ) radar is a radar system which can get the information of range and velocity through modulating the frequency of continuous wave
線性調頻連續波( lfmcw )雷達是一種通過對連續波進行頻率調制來獲得距離與速度信息的雷達體制。Because of the advantages of no range blind area, high range resolution, low signal power and simple structure, lfmcw ( linear frequency modulation continuous wave ) radar attracted more and more attention recently
線性調頻連續波( lfmcw )雷達是一種通過對連續波進行頻率調制來獲得距離與速度信息的雷達體制系統。由於其具有無距離盲區、高距離解析度、低發射功率、結構簡單,便於集成化等優點,適合用於液位測量系統。Via theoretical analyzing, we can find that the step reference waveform modulation strategy is an ideal one when frequency modulation ratio is not very high
通過理論分析,可以看出階梯波調制pwm的確是在頻率調制比不高時較好的調制方式。For ac discrete digital signal, the zero - calculating method is applied to calculate the true zero in the periodic signal. for the measurement of ac and dc voltage spectrum, the faster fourier transform ( fft ) is used. to measure dc voltage ripple spectrum and frequency modulation of ac voltage, the digital filter is used
其中對于交變的離散數字量,採用零點撿出技術計算周波信號的真實過零點;對于交直流電壓頻譜,採用快速傅立葉變換進行頻譜分析;對于直流電壓脈動和頻率調制,採用數字濾波器進行濾波后再做分析處理。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。Future mobile communications have to support the transmission of high rate data and multimedia applications in the radio spectrum, which is already extremely scarce. the basic idea of adaptive coded modulation is to maintain a constant throughput by varying the transmitted power level, symbol transmission rate, constellation size, coding rate or any combination of these parameters. thus, without sacrificing bit - error rate ( ber ), these schemes provide high average spectral efficiency by transmitting at high speeds under favorable channel conditions, and reducing throughput as the channel degrades
自適應編碼調制( adaptivecodedmodulation , acm )的基本思想是在不犧牲系統傳輸性能(比如ber )為代價的前提下,通過單獨改變發送功率、波特率、編碼方案、碼率、調制方式,或者是綜合改變前面所述的各種參數,在有利的通道條件下,獲得較大的吞吐量,當通道質量下將時,相應地降低傳輸速率,最終達到提高平均頻譜效率的目的。分享友人