基于狀態(tài)機的信號發(fā)生器外文翻譯

1、本科畢業(yè)設(shè)計（論文） 外文翻譯浙江師范大學(xué)本科畢業(yè)設(shè)計(論文)外文翻譯 譯文：波形發(fā)生器基礎(chǔ)崔靈智 山東水利職業(yè)學(xué)院院刊測試設(shè)備應(yīng)用需要先進的通信信號刺激信號不同從真實世界的模擬信號的捕獲播放。儀器產(chǎn)生的信號源的信號刺激,應(yīng)用于被測裝置(DUT)。因此,信號來源構(gòu)成一類重要測試儀器。這篇文章描述一個任意波信號發(fā)生器的應(yīng)用作為通用函數(shù)發(fā)生器和波形發(fā)生器。 本文描述任意波信號發(fā)生器的特點及應(yīng)用。雖然不同類型信號源的術(shù)語不規(guī)范,但在信號、函數(shù)和波形發(fā)生器的命名約定上還是有普遍的共識的。該信號發(fā)生器提供了一種高保真的正弦波信號，頻率從低頻率到高頻的千兆赫。衰減、調(diào)制和清除是一種典型特征的信號發(fā)生器。要

2、產(chǎn)生不同的模擬信號需要設(shè)計不同的硬件電路, 且產(chǎn)生的信號頻率受限, 失真也比較大。隨著數(shù)字信號處理技術(shù)及計算機技術(shù)的發(fā)展, 利用數(shù)字方法在相同的電路連接條件和計算機控制下就可以產(chǎn)生任意需要的波形, 且具有高精度、高可靠性、高靈活性和重復(fù)性好的特點一個函數(shù)發(fā)生器是一種低頻率儀器能提供各種波形。函數(shù)發(fā)生器提供這些標(biāo)準(zhǔn)函數(shù)頻率從直流至幾兆赫,通常提供很大的電壓范圍。任意波形發(fā)生器(AWG)是一個高度靈活的信號源,它能產(chǎn)生任意波形,建立了逐點數(shù)字記憶。所構(gòu)造的波形用數(shù)模轉(zhuǎn)換器轉(zhuǎn)化為模擬信號，(DAC)操作的時鐘速率達(dá)到幾千兆赫。任意波形發(fā)生器也可以代替?zhèn)鹘y(tǒng)函數(shù)發(fā)生器采用on-instrument算法生

3、成標(biāo)準(zhǔn)功能。 任意波形發(fā)生器輸出信號的類型，用AWG合成各種各樣的波形可能得到廣泛應(yīng)用，分為四類:標(biāo)準(zhǔn)功能,先進的功能,任意波形和波形序列。一、標(biāo)準(zhǔn)功能 標(biāo)準(zhǔn)函數(shù)包括正弦波、方波、脈沖波形、三角波、斜坡通常應(yīng)用于諸如測試基帶、音頻、聲納,超聲波和視頻元件和電路?？梢赃M行一些與標(biāo)準(zhǔn)函數(shù)波形的測試包括頻率響應(yīng)特性,線性度表征設(shè)備,數(shù)字邏輯和DC-offset信號的產(chǎn)生。采用頻率響應(yīng)的被測裝置(DUT)其特點是使用波形的反應(yīng)。二、先進的功能 大多數(shù)AWGs等提供其他先進的功能，例如多聲部,AM、FM、心臟、高斯脈沖、洛倫茲脈沖、噪音等。現(xiàn)代戰(zhàn)爭是爭奪電子頻譜控制權(quán)的戰(zhàn)爭，而頻率合成器可以產(chǎn)生電子頻譜

4、，因而頻率合成器被人們喻為眾多電子系統(tǒng)的“心臟”，具有很重要的應(yīng)用價值，廣泛應(yīng)用在空間通信、雷達(dá)測量、遙測遙控、無線電定位、衛(wèi)星導(dǎo)航和數(shù)字通信等先進的電子系統(tǒng)中。通常這些先進功能應(yīng)用在特定行業(yè)上。例如,應(yīng)用在醫(yī)療器械檢測的haversine(正弦波形和直流偏置這樣負(fù)面高峰等于0V)和心臟信號都是典型的波形信號。不同的脈沖形狀顯示另一個應(yīng)用程序特定的波形。由于計算所需要轉(zhuǎn)換信號，標(biāo)準(zhǔn)的脈沖波形刺激DUT以寬闊的諧波含量顯示。其他類型的脈沖波形平滑過渡,形成了有諧波含量為特定的應(yīng)用程序。這是一個任意形狀sinc脈沖頻譜與bandwidth-limited脈沖。Sinc脈沖用于描述或刺激溝通渠道由于

5、有限的帶寬。洛倫茲和高斯脈沖用于刺激模擬信號從磁盤驅(qū)動器。高斯脈沖也被用來刺激散布或傳播色散光纖電纜傳輸。指數(shù)脈沖用來刺激物理現(xiàn)象時很有用的,如充電電路。其他先進的波形用來設(shè)計驗證和生產(chǎn)測試電子線路和部件使很有用的。調(diào)頻信號中使用的AM/FM調(diào)頻的測試。多頻信號的互調(diào)失真是用于測試(IMD)用于放大器和其他通信部件，寬帶隨機噪聲是用于注射進入系統(tǒng)測量噪聲等噪聲系數(shù)。三、任意波形 任意波包括逐點用戶定義的波形合成。這提供了無限的靈活性,以用戶創(chuàng)建定制的波形不能用在儀器上。用戶負(fù)載波形數(shù)據(jù)編碼對儀器的記憶和程序的波形尺寸及DAC的時鐘頻率。DAC時鐘的速度設(shè)定的時間間隔,從每個數(shù)據(jù)點轉(zhuǎn)化為一種模擬

6、信號數(shù)字?jǐn)?shù)據(jù)和波形,用戶定義的任意波形總時間的大小控制。 任意波形發(fā)生器出現(xiàn)在大量的ATE測試情況,比如這一代的合規(guī)波形的合成,復(fù)合信號的組合,或用數(shù)字示波器捕獲的播放信號。信號發(fā)生器是一種常用的儀器,能夠?qū)崿F(xiàn)各種波形,不同頻率的輸出,電子測試系統(tǒng)的重要部件可以創(chuàng)建任意波形的例子的數(shù)學(xué)模型包括信息上傳到AWG的一段視頻編碼模式,一種顏色條測試信號,使用串行通信的或者是一個噪聲的正弦形數(shù)字脈沖流與小脈沖。真實世界的信號,如一個定制的視頻幀可捕捉并打了用示波器AWG回。另一個常見的AWG應(yīng)用結(jié)合某射頻/微波信號發(fā)生器，它在實際電路中應(yīng)用很廣泛。復(fù)雜的調(diào)制被創(chuàng)建和生成的,并將其應(yīng)用于AWG調(diào)制輸入端

7、口上的高頻信號發(fā)生器,創(chuàng)造出了一種射頻/微波調(diào)制的輸出。四、波形序列 波形序列提供一個機制來拼湊標(biāo)準(zhǔn)或任意波形來創(chuàng)建用戶定義在階段復(fù)合波形。通常情況下,一個波形庫包含波形數(shù)據(jù)中所用的不同階段波形序列，波形數(shù)據(jù)在圖書館和重用提供迴圈在一個序列的靈活性,以創(chuàng)造長波形序列。 選擇一個任意波形發(fā)生器，現(xiàn)如今像電子元件變得日益復(fù)雜,更復(fù)雜的信號刺激是必需的，也是符合市場需求的。在電子測量儀器家族中,信號發(fā)生器是一種很重要的儀器,它是電子測試系統(tǒng)的重要部件,是決定電子測試系統(tǒng)性能的關(guān)鍵設(shè)備之一。對數(shù)字信號發(fā)生器的設(shè)計進行研究具有很大的發(fā)展?jié)摿ΜF(xiàn)代波形發(fā)生器是非常強大的,但也能為用戶大大增加復(fù)雜性應(yīng)用。任意

8、波形發(fā)生器,是工具發(fā)現(xiàn)在大多數(shù)的測試系統(tǒng),是一個非常強大的信號合成的工具。不幸的是,很多用戶利用只是一小部分的強大功能,他們能得到一個AWG。 正確的選擇是很容易讓人對AWG產(chǎn)生恐懼感，當(dāng)比較規(guī)格如DAC的分辨率,時鐘頻率和拓?fù)浣Y(jié)構(gòu),記憶深度、排序、掃地、觸發(fā)和同步。這一節(jié)描述的一些共同特征的基礎(chǔ)上,提出一種AWG中發(fā)現(xiàn)的技術(shù)差異,探討了各種信號產(chǎn)生技術(shù)動態(tài)范圍的局限性,由于噪聲、準(zhǔn)確度和分辨率,在此基礎(chǔ)上提出了信號的保真度的影響時鐘拓?fù)洹?強大的任意波信號發(fā)生器的特點在現(xiàn)代測控領(lǐng)域，任意波形信號發(fā)生器已經(jīng)成為系統(tǒng)研發(fā)和調(diào)試必不可少的工具。而目前市場上的信號發(fā)生器價格昂貴，體積比較大，而且波形

9、可編程靈活度小，不能滿足實際的需要除了能夠生成標(biāo)準(zhǔn)功能,任意波形、和波形序列,一個AWG提供其他功能的簡化生成一個測試信號。這一節(jié)描述的特點共同AWG觸發(fā)、掃地、二進制調(diào)制,同時下載和播放,并同步輸出。 觸發(fā)或者爆操作模式提供了一種同步的一個或多個輸出一個外部事件。在破裂模式,該儀器產(chǎn)生離散數(shù)據(jù)的波形周期在一個觸發(fā)事件。這個循環(huán)數(shù)的產(chǎn)生是典型的可編程的。標(biāo)準(zhǔn)函數(shù)和任意波形、一個周期是一個時期的波形。對任意序列,一個周期是一個完整的進展在所有的波形的序列。掃描操作模式提供了一種方法來產(chǎn)生一掃頻輸出信號。當(dāng)使用掃模式、波形形狀記憶是不變,在數(shù)模轉(zhuǎn)換器和DAC的時鐘頻率在線性或?qū)?shù)時尚橫掃對手。典型

10、地,開始和停止頻率可編程的,隨著時間的橫掃從開始到停止。掃的方向上、下、或上升和下降也是典型的可選。波形發(fā)生器是電子設(shè)計以及教學(xué)、科研中應(yīng)用最廣泛的儀器之一。如果能用相對簡單的實現(xiàn)方式和較少的成本產(chǎn)生具有優(yōu)秀穩(wěn)定度和精確度的常用波形，無疑將在這些領(lǐng)域中得到廣泛的應(yīng)用。 二進制調(diào)制模式允許外部或內(nèi)部調(diào)制源之間切換被應(yīng)用到兩個預(yù)波形。這項功能可以使振幅移位鍵控、移頻鍵控,相移鍵控,二者之間的切換,或者封閉任意波信號的產(chǎn)生。為每一種應(yīng)用程序、波形為兩者狀態(tài)都預(yù)緊和輸出波形根據(jù)國家確定的調(diào)制源。通常是可選的調(diào)制源之間的外部資金來源和外部。例如,一個內(nèi)部時鐘源可以用來切換兩個波形之間在用戶自定義的速率。

11、 一些任意波形發(fā)生器提供同時下載和播放功能特性,它使輸出波形的切換在一個無縫的時尚。同時提供上傳下載和播放AWG接下來的波形而訪問該儀器是生成其現(xiàn)有的輸出波形。在這種類型的AWG架構(gòu),每個波形DAC擁有雙重記憶緩沖區(qū)。當(dāng)一個緩沖食為數(shù)據(jù)流的轉(zhuǎn)換到DAC的模擬輸出,另一個緩存可以裝的下的波形產(chǎn)生。這雙乒乓球緩沖結(jié)構(gòu)使瞬時、無縫波形切換一旦收到命令,觸發(fā)事件或調(diào)制輸入狀態(tài)。 許多AWGs提供同步脈沖(同步),它可以發(fā)送到前面板和背板的產(chǎn)出。典型的同步輸出二進制輸出,使可編程序在用戶定義的時間切換位置之波形周期。同步輸出是有用的生成時間標(biāo)記,或觸發(fā)輸出脈沖的一種精確的相對位置輸出的模擬波形。原文：W

12、aveform Generator Fundamentals CuiLingZhi Publication Of Shandong water conservan college Test equipment applications require signal stimuli varying from advanced communication signals to the playback of captured real-world analog signals. Signal source instruments generate the signal stimulus that

13、is applied to a device under test (DUT). Consequently, signal sources comprise an important class of test instruments. This article describes applications of an arbitrary waveform generator as a general purpose function generator and waveform generator. This paper describes the characteristics and a

14、pplications of arbitrary waveform generators. Although the terminology for the different classes of signal sources is not standardized, there is a general market consensus on the naming conventions for signal, function and waveform generators. A signal generator provides a high-fidelity sine wave si

15、gnal ranging from low frequencies to many GHz. Attenuation, modulation, and sweeping are typical features of a signal generator. A function generator is a lower-frequency instrument that provides sine, square, pulse, triangle and ramp waveforms. Function generators provide these standard functions f

16、rom DC to a few MHz, and typically provide large voltage ranges. An arbitrary waveform generator (AWG) is a highly flexible signal source that generates any arbitrary waveform that has been constructed point-by-point in digital memory. The constructed waveform is converted to an analog signal using

17、a digital-to-analog converter (DAC) operating at clock rates up to a few GHz. An arbitrary waveform generator can also substitute as a conventional function generator by using on-instrument algorithms to generate standard functions. Arbitrary Waveform Generator Output Signal Types The variety of wav

18、eforms that may be synthesized with an AWG can be broadly applicated into four categories: standard functions, advanced functions, arbitrary waveforms, and waveform sequences.Standard Functions Standard functions include the sine, square, pulse, triangle, and ramp waveforms that are commonly used in

19、 applications such as the testing of baseband, audio, sonar, ultrasound, and video components and circuits. Some tests that can be performed with standard function waveforms include frequency response characterization, device linearity characterization, digital logic generation and DC-offset signal

20、. The frequency response of a device under test (DUT) can be characterized by waveform responsesAdvanced Functions Most AWGs provide other advanced functions such as multi-tone, AM, FM, cardiac, Gaussian pulse, Lorentz pulse, noise and others . These advanced functions typically address specific app

21、lications in specific industries. For example, haversine (sine waveform with DC offset such that the negative peak is at 0V) and cardiac signals are typical waveforms used in medical device testing. Different pulse shapes show another example of application-specific waveforms. Standard pulse wavefor

22、ms excite the DUT with a broad harmonic content due to the sharp transitions in the signal. Other types of pulse waveforms have smoother transitions that shape the harmonic content for specific applications.The sinc pulse is a shaped pulse with a bandwidth-limited frequency spectrum. Sinc pulses are

23、 used to characterize or excite communications channels with limited bandwidths. Lorentz and Gaussian pulses are used to simulate the signals from magnetic disk drives. The Gaussian pulse is also used to simulate dispersion or spreading in fiber optic cable transmission. Exponential pulses are usefu

24、l to simulate physical phenomenon such as a resistor-capacitor charging circuit. Other advanced waveforms are useful for the design verification and production testing of electronic circuits and components. AM and FM signals are used within AM/FM radio testing. Multi-tone signals are used for interm

25、odulation distortion (IMD) testing for amplifiers and other communication components. Broadband random noise is used for injecting noise into a system for measurements such as noise figure.Arbitrary Waveforms Arbitrary waveforms involve the point-by-point user-defined waveform synthesis. This provid

26、es unlimited flexibility to the user to create custom waveforms not available on the instrument. The user loads waveform data codes to instrument memory, and programs the waveform size and DAC clock rate. The DAC clock rate sets the time interval at which each data point is converted from digital da

27、ta to an analog signal, and the waveform size controls the total duration of the user-defined arbitrary waveform. Arbitrary waveform generators appear in a number of ATE test situations such as the generation of compliance waveforms, the synthesis of compound signal combinations, or the playback of

28、signals captured with a digital oscilloscope. Examples of arbitrary waveforms that can be created mathematically and uploaded to the AWG include a video color bar pattern, an encoded serial communication test signal, a noisy sinusoid, or a digital pulse stream with runt pulses. Real-world signals su

29、ch as a custom video frame can be captured with an oscilloscope and played back with the AWG. Another common AWG application is in combination with an RF/microwave signal generator. Sophisticated modulation is created and generated by the AWG and applied to a modulation input port on the high-freque

30、ncy signal generator to create a modulated RF/microwave output.Waveform SequencesWaveform sequences provide a mechanism to piece together standard or arbitrary waveforms in stages to create user-defined compound waveforms. Typically, a waveform library contains waveform data that are used in the sta

31、ges of the waveform sequence. Waveform data in the library are reused and looped in a sequence to provide the flexibility to create long waveform sequencesSelecting An Arbitrary Waveform Generator As electronics become increasingly complex, more sophisticated signal stimuli are required. Modern wave

32、form generators are extremely powerful, but can also add significant complexity for the user. The arbitrary waveform generator, an instrument found in most test systems, is a very powerful signal synthesis tool. Unfortunately, many users take advantage of only a small fraction of the powerful featur

33、es available to them in an AWG. Selecting the right AWG can be daunting when comparing specifications such as DAC resolution, clock rates and topology, memory depth, sequencing, sweeping, triggering and synchronization. This section describes some of the common features found in an AWG, presents the

34、 technical differences between various signal generation techniques, discusses dynamic range limitations due to noise, accuracy and resolution, and presents the signal fidelity impact of clock topology.Powerful Arbitrary Waveform Generator Features In addition to the ability to generate standard fun

35、ctions, arbitrary waveforms, and waveform sequences, an AWG offers other features to simplify the generation of a test signal. This section describes the common AWG features of triggering, sweeping, binary modulation, simultaneous load and play, and synchronization outputs. Triggering or burst opera

36、ting mode provides a method to synchronize one or more outputs to an external event. In burst mode, the instrument generates a discrete number of waveform cycles upon a trigger event. The number of cycles to generate is typically programmable. For standard functions and arbitrary waveforms, a cycle

37、is one period of the waveform. For arbitrary sequences, a cycle is one complete progression through all the waveforms in the sequence. The sweep operating mode provides a method to generate a swept-frequency output signal. When using sweep mode, the waveform shape in DAC memory is constant, and the

38、DAC clock frequency in swept a linear or logarithmic fashion. Typically, the start and stop frequencies are programmable, along with the sweep time duration from start to stop. Sweep directions of up, down, or up and down are also typically selectable. Binary modulation mode allows an external or in

39、ternal modulation source to be applied to switch between two preloaded waveforms. This functionality enables amplitude shift keying, frequency shift keying, phase shift keying, toggling between two arbitrary waveforms, or gated signal generation. For each of these applications, waveforms for both states are preloaded and the output wav