?modulator

modulator 發(fā)音

['m?djuleit?, -d?u-]

英：　　美：

modulator 中文意思翻譯

modulator 網(wǎng)絡(luò)釋義

n. [電子] 調(diào)幅器，[電子][通信] 調(diào)制器；調(diào)節(jié)人

modulator 詞性/詞形變化，modulator變形

名詞復數(shù)形式:modulators

modulator 短語詞組

1、class ab modulator ─── [電] AB類調(diào)變器

2、heterodyne modulator ─── [電] 見mixer

3、class a modulator ─── [電] A類調(diào)制器

4、digital modulator ─── [計] 數(shù)字調(diào)制器

5、audio-frequency shift modulator ─── [電] 聲頻位移調(diào)變器

6、hall-effect modulator ─── [電] 霍耳效應調(diào)制器

7、doubly-balanced modulator ─── [電] 雙平?jīng)_調(diào)變器

8、balance modulator ─── [電] 平衡調(diào)制器

9、contact modulator ─── [電] 接觸調(diào)變器

10、chrominance-subcarrier modulator ─── [電] 彩色信號調(diào)制器

11、class b modulator ─── [電] B類調(diào)制器

12、balanced modulator ─── [電] 平衡調(diào)制器

13、crystal modulator ─── [電] 晶體調(diào)變器

14、lattice modulator ─── [計] 格子調(diào)制器

15、class-b modulator ─── [電] B類調(diào)變器

16、allosteric modulator ─── [機] 異位效應物

17、group data modulator ─── [計] 基群數(shù)據(jù)調(diào)制器

18、frequency modulator ─── [電] 調(diào)頻器

19、balance ring modulator ─── [電] 平衡環(huán)式調(diào)制器

20、chrominance modulator ─── [電] 色訊調(diào)變器

modulator 常用詞組

spatial light modulator ─── 空間光調(diào)制器

phase modulator ─── 相位調(diào)制器；調(diào)相器

frequency modulator ─── 調(diào)頻器；頻率燈器

modulator 相似詞語短語

1、joculator ─── 戲謔者

2、demodulator ─── n.[電子]解調(diào)器

3、modulatory ─── adj.調(diào)節(jié)的；調(diào)制的

4、modulation ─── n.[電子]調(diào)制；調(diào)整

5、modulated ─── adj.已調(diào)的；被調(diào)的；v.調(diào)整，調(diào)節(jié)；吟詠；改變（嗓音的）音量（modulate的過去分詞）

6、moderator ─── n.[核]慢化劑；仲裁人；調(diào)解人；緩和劑

7、modulate ─── vt.調(diào)節(jié)；（信號）調(diào)制；調(diào)整；vi.調(diào)制；轉(zhuǎn)調(diào)

8、adulator ─── n.好奉迎者

9、modular ─── adj.模塊化的；模數(shù)的；有標準組件的

modulator 常見例句（雙語使用場景）

1、A combinatory,resonant-mode,high power,charging power supply for linear modulator is described. ─── 介紹了一種供線型調(diào)制器用的大功率組合逆變充電電源。

2、Spatial Light Modulator (SLM) and CCD detector are generally used as input and output devices in volume holographic data storage system. ─── 體全息存儲系統(tǒng)中通常采用SLM和ccd作為輸入輸出器件。

3、The modulator tube diverts current from the RF amplifier. ─── 調(diào)制管轉(zhuǎn)移射頻放大器中的電流。

4、Electrical-Poling Technology of Lithium Tantalate for Quasi-Velocity-Matching Phase Modulator[J]. ─── 引用該論文 呂航,陳險峰,陳理軍,張軍鋒,陳玉萍,夏宇興.

5、Signals are modulated through amplitude modulator and phase modulator respectively then reconstruct at the PA stage. ─── 兩個信號再經(jīng)由震幅調(diào)變器和相位調(diào)變器分別做調(diào)變，最后在放大器端重新將信號重建回來。

6、Laser-diode pumped Q-switched ytterbium-doped fiber laser is studied experimentally by controlling the switching time of acousto-optic modulator (AOM). ─── 在實驗上，研究了開關(guān)時間對激光二極管泵浦的調(diào)Q摻鐿光纖激光器的影響。

7、Electric-optical modulator; quasi-phase-matching; degenerate optical parametric amplifier: Amplitude quadrature squeezed light field; coupled oscillator. ─── 01振幅調(diào)制器;準相位匹配;簡并光學參量放大;正交振幅壓縮態(tài);耦合諧振子

8、The differential input is sampled at up to 40 MSPS by an analog modulator. ─── 差分輸入由模擬調(diào)制器以最高40MSPS的采樣速率進行采樣。

9、CCK,as a neurotransmitter or modulator,has neuroprotective and neuroreparable effects. ─── 作為一種神經(jīng)遞質(zhì)或調(diào)質(zhì),CCK具有神經(jīng)保護和修復作用。

10、This article summarizes the manufacture technology on modul heat recovery boiler, especially for the difficults in manufacturing. ─── 主要對模塊式余熱爐的制造技術(shù)進行歸納和總結(jié),對制造中的難點進行分析和說明。

11、The electrooptic effect of LiNbO3 crystal is analyzed, based on which a modulator used in space polarization encoding system is designed. ─── 對鈮酸鋰晶體的電光效應進行了理論分析，在此基礎(chǔ)上設(shè)計了基于普科爾效應的空間偏振編碼調(diào)制器。

12、Liquid Crystal Spatial Light Modulator Based on BSO[J]. ─── 引用該論文 Shi Tao,Huang Ziqiang,Zhang Cuiyu.

13、Therefore, there's in need we should combine immune modulator, and anti-virus like polysaccharide, thymopentin or something, must combine anti-virus drugs. ─── 因此，我們可以合并免疫調(diào)節(jié)藥物，例如云芝多糖，胸腺肽等，然后和抗病毒藥物一起使用。

14、A local nonlinear feedback loop (LNFL) technique and a sigma-delta modulator (SDM) for promoting highly stable oversampling using the LNFL technique. ─── 一種局部非線性回授?路法，以及并利用此一局部非線性回授?路法改良之高穩(wěn)定性超取樣積分三角調(diào)變器。

15、Simultaneous Modulation of Different-Channel Light Based on Single-Channel Electrooptic Modulator[J]. ─── 引用該論文 楊艷芳,印杰,曹莊琪,沈啟舜.

16、The patterned screen is treated as the combination of a perfect white screen and a color modulator. ─── 該方法將帶圖案的屏幕處理為純白色屏幕和顏色調(diào)制器的合成。

17、AbE is potentially a biological response modulator for hemopoietic and immuno-regulstion. ─── AbE有可能成為一種能改善造血與免疫功能的生物反應調(diào)節(jié)劑。

18、Employing a liquid crystal modulator and CCD camera, a phase sensitive images system has been investigated experimentally for various fluorescence lifetimes. ─── 利用液晶調(diào)制器和ccd探頭組成的熒光相位成像系統(tǒng)，實現(xiàn)了不同熒光壽命物體的熒光成像，時間分辨率達到了亞毫秒量級。

19、Analytical Study of Electrooptic Modulator Using Annealed Proton Exchanged Planar Waveguide[J]. ─── 引用該論文 廖尉鈞,陳險峰,曾祥龍,李劬,陳英禮.

20、It consists of an analog modulator and a digital decimator. ─── 它由一個模擬的調(diào)制器和一個數(shù)字降采樣濾波器組成。

21、The download rate is 32Mbps when using 64 QAM modulator in 8MHz bandwidth channel. ─── 在CATV網(wǎng)采用64QAM調(diào)制技術(shù)，每個8MHz帶寬的電視頻道可提供高達32Mbps的凈下行速率。

22、A classical space-vector pulsewidth modulator (SVPWM) with equal duration of application of zero-state vectors U0 and U7 was modified. ─── 常用的SVPWM中零矢量U0和U7的工作時間是平均分配的。

23、Studies are under way to test the efficacy of treating HBV infection by combining an immune modulator with a nucleoside or nucleotide analogue inhibitor. ─── 免疫調(diào)節(jié)劑和核苷/核苷類似物聯(lián)合治療HBV感染的研究正在進行。

24、The design of a Digitally Programmable Oscillator (DPO) is described for applications in the area of FSK modulator. ─── 介紹了一種可用作FSK調(diào)制器的數(shù)字可編程振蕩器(DPO)的設(shè)計。

25、In order to meet the requirement of RF phase stability, all 48 sets of the PFN in HV modulator are repeatedly adjusted to obtain optimum result. ─── 對高壓調(diào)制器的48節(jié)人工線做了全面的優(yōu)化調(diào)整。

26、Compared with the conventional polymer electro-optic modulator using prism coupling technique, the novel modulator is more compact and easier to be integrated. ─── 與傳統(tǒng)的棱鏡耦合方式的聚合物電光調(diào)制器相比，自由空間耦合技術(shù)的引入使此類電光調(diào)制器結(jié)構(gòu)更加緊湊、更易于陣列化集成。

27、Modulator control scheme for transmission. Default is AM. ─── 傳送調(diào)制控制配置。缺省是。

28、A new grating light modulator(GLM), which consists of a moveable plate array and a fixed grating, was proposed. ─── 提出了一種新型的光柵光調(diào)制器（GLM），它由可動平板陣列和固定光柵構(gòu)成，通過可動平板的垂直運動，達到調(diào)制光束的目的。

29、Even harmonic mixer can suppress even-order mixing products and carrier leakage, and associated EVM when it is used as modulator. ─── 分諧波混頻器能夠有效抑制偶次組合頻率分量和本振泄漏，可以獲得較高的動態(tài)范圍，具有低失真、低載波泄漏、誤差矢量小的特點。

30、Explored the design of the mouthpiece for AES/EBU With digital frequency modulator system. ─── 與相似的文獻。

31、A low-pass programmable digital filter with adjustable filter cutoff, output rate, and settling time processes the modulator output. ─── 低通道可編程的數(shù)字式濾波器與可調(diào)整的過濾器開關(guān),的輸出率和沉淀時間過程調(diào)制器的輸出量。

32、The key is something called a selective androgen receptor modulator, or SARM. ─── 關(guān)鍵是所謂選擇性雄激素受體調(diào)節(jié)劑，或行動情報處。

33、The utility model discloses a minimum frequency shift keying (MSK) modulator, and is applied to a digital information transmission system. ─── 最小移頻鍵控（MSK）調(diào)制器，適用于數(shù)字信息傳輸系統(tǒng)中。

34、To develop a new selective steroid receptor modulator is one of the targets in future study to treat osteoporosis. ─── 開發(fā)選擇性類固醇激素受體調(diào)節(jié)劑有望成為未來防治骨質(zhì)疏松藥物的研究方向。

35、Decrease in the design errors of the multimode waveguides and enhancement of etching uniformity can improve the characteristics of the thermo-optic modulator. ─── 減小模干涉耦合器的設(shè)計誤差提高刻蝕均勻性可以改善調(diào)制器的性能。

36、The subthalamic nucleus (STN), which is located in the indirect pathway of the basal ganglia circuitry, has been regarded as an important modulator of basal ganglia output. ─── 底丘腦核（Subthalamic nucleus, STN）位于基底神經(jīng)節(jié)環(huán)路的間接通路上，對基底神經(jīng)節(jié)的傳出活動具有重要的調(diào)節(jié)作用。

37、In a laser printer, a device that uses a modulator crystal to deflect a beam of light and effectively turn it on or off. ─── 在激光印刷機中的一種裝置，它利用一塊調(diào)制晶體使光束偏轉(zhuǎn)并將其接通或斷開。

38、They have an oversampling mechanism, a modulator, and a digital filter. ─── 它有過采樣結(jié)構(gòu)、調(diào)節(jié)器和數(shù)字濾波器。

39、In the experiments, principle of forming the rotator and application of the phase modulator to modulation of polarization direction are verified. ─── 實驗驗證了相位延遲器復合為旋光器和相位調(diào)制器轉(zhuǎn)換為偏振方向調(diào)制器的可行性。

40、Utilize FSK modulator, powerful anti-disturbing capability. ─── 商品描述：采用FSK調(diào)制方式，抗干擾能力強。

41、Cascading Acousto-Optic Modulator Used in Linear Chirp Waveform Coherent Ladar System[J]. ─── 引用該論文 楊蘇輝,吳克瑛,趙長明,劉杰,魏光輝.

42、In the experiment, we found the locking range of OEO was greatly affected by the bias voltage of modulator in the loop. ─── 實驗中發(fā)現(xiàn)OEO中凋制器的偏置電壓對OEO的注入鎖定范圍有很大影響.

43、The high precision terrain data in the STK/Terrain modul is used as data sources, which is converted to the OpenFlight format model that Creator or Vega can discriminated . ─── 以STK/Terrain 模塊中的高精度地形高程數(shù)據(jù)作為數(shù)據(jù)源,將其轉(zhuǎn)換成Creator 和Vega 能識別的OpenFlight 格式模型;

44、This paper mostly researches a pulse modulator which can be used in the microwave power module. ─── 主要研究一種可用于微波功率模塊的脈沖調(diào)制器。

45、Optical Transmitter by the light source, and the modulator driver components. ─── 光發(fā)射機是由光源、驅(qū)動器和調(diào)制器組成。

46、PTEN might be a negative modulator of the PI3K-Akt pathway and then plays an important role in the development of insulin resistance. ─── PTEN可能是一種重要的負性調(diào)節(jié)因子,調(diào)節(jié)三磷酸肌醇激酶(PI3Ks)/蛋白激酶B(Akt)所介導的信號傳導通路,在胰島素抵抗的發(fā)生、發(fā)展中起著重要的作用。

47、A new laser pulse-shaping system using an electro-optic modulator driven by an aperture-coupled-striplines (ACSL) electrical-waveform generator has been discussed in this paper. ─── 實現(xiàn)了一種新型的激光脈沖整形系統(tǒng),該系統(tǒng)使用了一個由孔徑耦合帶狀線(ACSL)電脈沖整形器驅(qū)動的電光調(diào)制器。

48、In fractional part, phase-compensation fractional PLL is a different kind of true fractional PLL with averaging fractional PLL using D-S modulator architecture. ─── 另外在非整數(shù)的實現(xiàn)方面，相位補償技術(shù)是一種真實非整數(shù)除數(shù)鎖相迴路不同于一般常見的三角積分的平均式非整數(shù)鎖相迴路。

49、Designed the air conditioner control modul based on sensors to check the air conditioner , so that energy was saved. ─── 并且，以家用空調(diào)器為對象，設(shè)計了以傳感器為核心的監(jiān)測模塊，通過檢測環(huán)境溫度來調(diào)整空調(diào)的工作狀態(tài)，達到了節(jié)約能源的目的。

50、is one of the most important components in HV pulse modulator. ─── 脈沖變壓器是高壓脈沖調(diào)制器的重要器件之一。

51、Job Description Facilitate business process analysis and re-engineering efforts for client EBS, Financial modul...... ... ─── 公司名稱：西艾(廣州)軟件開發(fā)有限公司工作地點：上海市發(fā)布時間：2009-4-14

52、Tamoxifen was the first estrogen modulator shown to increase surial and reduce the risk of breast cancer recurrence. ─── 三苯氧胺是第一個雌激素調(diào)節(jié)劑，可增加患者的生存率和降低乳腺癌復發(fā)的危險。

53、Other features include an integrated buffer to drive the reference as well as a fully differential amplifier to buffer and level shift the input to the modulator. ─── 其它特性包括：集成緩沖用來驅(qū)動基準電壓，以及集成完全差動放大器用來緩沖調(diào)制器輸入并進行電平轉(zhuǎn)換。

54、In this thesis, a novel analog deta-sigma modulator structure is introduced as well. ─── 反饋回路的引入可以提高整個電路的抗干擾能力。

55、An artficial intelligent neural network modul(ANNM)was built on the basis of experimental data of ion nitriding to predict the effects of ion nitriding process. ─── 以離子滲氮為例,建立了滲層性能預報神經(jīng)網(wǎng)絡(luò)模型;

56、In this paper, the relations between RF phase variation and the Pulse Form Net (PFN) in modulator of klystron are carefully studied through experiments. ─── 對微波相位的變化與速調(diào)管高壓調(diào)制器人工線之間的關(guān)系做了仔細的實驗研究。

57、This paper introduces the principles of filtering and phase compensation for the implementation of symmetry roll-off in 8-VSB modulator. ─── 介紹了采用濾波相位補償法原理，實現(xiàn)對稱滾降8-VSB調(diào)制器的硬件方案。

58、This paper uses growth modulator including of ETH,CCC,PP333 and IAA to soakage nutrient branch and fructi branch in shoot rapidity growth period. ─── 在葡萄 (秋黑 )新梢迅速生長期 ,運用ETH、CCC、PP333及IAA 4種調(diào)節(jié)劑 ,對營養(yǎng)枝、結(jié)果枝進行浸蘸試驗。

59、The OQPSK modulator imbalance and amplifier nonlinearity have a deleterious effect on the receiver performance. ─── OQPSK調(diào)制器的不均衡以及放大器的非線性對接收機的性能具有非常大影響。

60、Some researchers believe that these claims may be supported because of the herbs peculiar properties as an immune system modulator and antioxidant. ─── 一些研究者認為這些說法可能成立,因為這個植物獨特的性能，它可以作為一種免疫系統(tǒng)的調(diào)節(jié)和抗氧化劑。

61、The design concept of a radar deceptive jamming modulator is presented, and its implementation structure based on FPGA is put forward. ─── 提出了一種雷達欺騙干擾信號調(diào)制器的設(shè)計方案，給出了其在可編程門陣列（FPGA）中的實現(xiàn)結(jié)構(gòu)。

62、At the same time there also can be used to measure pulse circuit or pulse modulator for the pulse generator. ─── 同時還出現(xiàn)了可用來測量脈沖電路或用作脈沖調(diào)制器的脈沖。

63、Use of a single bit DAC in the modulator guarantees excellent linearity and dc accuracy. ─── 在調(diào)制器中使用單比特DAC可保證出色的線性度和直流精度。

64、That is to see it is a possible signal of rather strong earthquake in Qinghai province when the regional area modul... ─── 也就是說空間受調(diào)制的區(qū)域面積由大變小時可能是青海省發(fā)生較大地震的信號。

65、The effect of phase modulator of optical fiber gyro and light source stability on overall system property is analyzed. ─── 從理論上分析光纖陀螺位相調(diào)制器及光源不穩(wěn)定對整機性能特別是對漂移的影響。

66、The tensile strength of this kind of super-hybridcomposite material is obviously increased compared with the aluminum used,while the specific strength andspecific modul... ─── 對該材料的測試結(jié)果表明,其強度與所用的鋁相比有明顯提高,比強度、比剛度則大為提高,并且成本遠低于鋁,這種復合材料有望在工業(yè)上代替部分鋁。

67、A hologram record apparatus (100) includes a spatial light modulator (15) and a control device (18). ─── 一種全息記錄裝置(100)包括空間光調(diào)制器(15)和控制設(shè)備(18)。

68、Transmitter: Generates the radio-frequency (r-f) energy in the form of short, powerful pulses. Consists of the driver, modulator and r-f oscillator. ─── 發(fā)射器：由激勵器，調(diào)節(jié)器和射頻震蕩器組成，用以生成強大的短脈沖能量。

69、The job holder must have the following special training: Established practical user training in SAP (MM Modul, DVS, Workflow) Good PC user t... ─── 公司性質(zhì)：外商獨資公司規(guī)模：500-999人經(jīng)驗要求：3-5年最低學歷：本科/學士及同等學歷

70、The input signal is applied to a proprietary programmable gain front end, based on an analog modulator. ─── 一專門的可編程的增益從頭到尾輸入信號,建立一個模式調(diào)制器。

71、Quasi Velocity Matched Electrooptic Phase Modulator[J]. ─── 引用該論文 郭鳳珍,于長泰,小林哲郎.

72、The Up converter receives at its input the IF signal coming from the modulator and converts it on the RF transmission channel. ─── 上轉(zhuǎn)換器在它的來自調(diào)節(jié)器的輸入IF信號上接收和在射頻傳輸頻道上轉(zhuǎn)換。

73、An iterative decoding scheme is proposed for the concatenation of a convolutional code and a GMSK modulator. ─── 提出了卷積碼與GMSK（高斯最小移頻鍵控）調(diào)制器級聯(lián)系統(tǒng)的一種迭代譯碼方案。

74、Output channel 3 or channel 4 of radio frequency modulator can be selected by up/down toggle switch. ─── 射頻調(diào)制器的輸出頻道可以通過上/下?lián)軇娱_關(guān)選擇3頻道/4頻道。

75、Influence of the Optical Activity of BSO on Spatial Light Modulator[J]. ─── 引用該論文 孔迪,楊建坤,李修建,劉菊.

76、Allosteric enzymes may have more than one modulator. ─── 它可以有一個或多個調(diào)節(jié)物。

77、The elastic modul of short fibre composite material whose fibre s volume and direction are random distributed is calculated by means of the random medium micromechanics method. ─── 利用隨機介質(zhì)微觀力學方法對纖維大小、方向隨機分布的短纖維復合材料彈性模量進行了計算。

78、Optical fiber giro with piezoelectric ceramic phase modulator can improve checkout sensitivity and range of measurement. ─── 光纖陀螺采用壓電陶瓷相位調(diào)制器可以提高檢測靈敏度和測量范圍。 一種實用。

79、The foundation is given to design the good external modulator optical transmitter by calculating CSO. ─── 為設(shè)計性能良好的外調(diào)制光發(fā)射機 提供了依據(jù)。

80、In this formula, M is the order of the modulator, and K is the oversampling ratio during the conversion. ─── 在這個公式中，M是調(diào)節(jié)器階數(shù)，K是轉(zhuǎn)換過程中的過采樣速率。

81、The result of the measurement shows that voltage-phase characteristic curve of phase-polarization modulator has good linearity . ─── 測量結(jié)果表明，相位-偏振調(diào)制器的伏-相特征曲線具有良好的線性特性。

82、The modulator in one modem connects to the demodulator on the other ,allowing data to be sent in either direction. ─── Modem中的調(diào)制器與另一端Modem的解調(diào)器相連接，允許數(shù)據(jù)向任一方向發(fā)送。

83、Using a 1-bit internal ADC, the internal converter modulator in Figure 1 samples the input signal, producing a coarse, quantized output. ─── 使用1位內(nèi)部ADC，圖1中內(nèi)部轉(zhuǎn)換調(diào)節(jié)器采集輸入信號，產(chǎn)生粗量化的輸出作為輸入信號。

84、A variac and transformer, at far right, supply high voltage for the modulator. ─── 為調(diào)制器提供高電壓的一臺自耦變壓器和一臺變壓器在右邊遠處。

85、Allosteric site A part of an enzyme to which a specific effector or modulator can be attached. ─── 別構(gòu)部位：可以結(jié)合特定效應物或者調(diào)節(jié)物的酶的一個部分。

86、YANG Wen-zheng, YANG Qing, CHEN Feng, et al.A study on spatial light modulator of bacteriorhodopsin film[J].Acta Physica Sinica, 2003, 52(3): 761-766. ─── [20]楊文正,楊青,陳烽,等.基于細菌視紫紅質(zhì)薄膜的空間光調(diào)制器實驗研究[J].物理學報,2003,52(3):761-766.

87、DIP switch,patch panel ,connector,modul etc. ─── DIP開關(guān)，綜合布線類產(chǎn)品，（配線架，模塊，連接器，面板）

88、By using an unbalanced dual parallel Mach-zehnder modulator (DPMZM) followed by optical filtering, a linearized OSSB signal is obtained. ─── 利用一種不均衡的平行調(diào)制器和光濾波器，我們得到線性化的單邊帶光信號。

89、In this article, the schematic diagram, main specifications and the realization of the circuits of the phase differential modulator and measurer are described. ─── 介紹了相位差調(diào)制器及測量器的原理框圖、要性能指標及電路實現(xiàn)。

兩臺計算機之間利用**線路傳送數(shù)據(jù)信號時，必須的設(shè)備是什么？

兩臺計算機之間利用**線路傳送數(shù)據(jù)信號時，必須的設(shè)備是調(diào)制解調(diào)器。

調(diào)制解調(diào)器是一種計算機硬件，它能把計算機的數(shù)字信號翻譯成可沿普通**線傳送的模擬信號，而這些模擬信號又可被線路另一端的另一個調(diào)制解調(diào)器接收，并譯成計算機可懂的語言。這一簡單過程完成了兩臺計算機間的通信。

兩臺計算機之間利用電話線路傳送數(shù)據(jù)信號時，必須的設(shè)備是什么？

Modem即調(diào)制解調(diào)器。 調(diào)制解調(diào)就是我們常說的Modem，其實是Modulator（調(diào)制器）與Demodulator（解調(diào)器）的簡稱，中文稱為調(diào)制解調(diào)器。計算機內(nèi)的信息是由“0”和“1”組成數(shù)字信號，而在電話線上傳遞的卻只能是模擬電信號（模擬信號為連續(xù)的，數(shù)字信號為間斷的）。

于是，當兩臺計算機要通過電話線進行數(shù)據(jù)傳輸時，就需要一個設(shè)備負責數(shù)模的轉(zhuǎn)換。這個數(shù)模轉(zhuǎn)換器就是我們這里要討論的Modem。計算機在發(fā)送數(shù)據(jù)時，先由Modem把數(shù)字信號轉(zhuǎn)換為相應的模擬信號，這個過程稱為“調(diào)制”，也成D/A轉(zhuǎn)換。

經(jīng)過調(diào)制的信號通過電話載波傳送到另一臺計算機之前，也要經(jīng)由接收方的Modem負責把模擬信號還原為計算機能識別的數(shù)字信號，這個過程我們稱“解調(diào)”，也稱A/D轉(zhuǎn)換。

正是通過這樣一個“調(diào)制”與“解調(diào)”的數(shù)模轉(zhuǎn)換過程，從而實現(xiàn)了兩臺計算機之間的遠程通訊。