函數(shù)信號發(fā)生器 外文文獻翻譯

1、畢業(yè)設(shè)計（論文）中英文資料題目 函數(shù)信號發(fā)生器專 業(yè) 名 稱 電子信息工程班 級 學(xué) 號 118501106學(xué) 生 姓 名 蔡偉攀指 導(dǎo) 教 師 鄧洪峰填 表 日 期 2015 年 3 月 27 日外文資料譯文 任意波形信號發(fā)生器的設(shè)計陳曉和陳健翔南京工業(yè)大學(xué)電子與信息工程學(xué)院，信息科學(xué)與技術(shù),210044中國，南京摘要信號發(fā)生器在電子測量儀器、電子電路、自動控制、雷達和其他電子系統(tǒng)的溝通中起著非常重要的作用,。直接數(shù)字合成(DDS)技術(shù)可以很容易地控制信號的頻率波形的直接合成。本文設(shè)計了一個振幅和頻率調(diào)制信號發(fā)生器，采用AD9850頻率合成器和AT89S52單片機(SCM)為核心。詳細的設(shè)計

2、原理和思路進行了討論。DDS芯片AD9850的用于生成波形。外部輸入的頻率數(shù)據(jù)可以通過簡單的并行或串行通訊接口與單片機轉(zhuǎn)化為芯片的頻率相位控制字。幅度調(diào)制是由AD7520芯片實現(xiàn)。該系統(tǒng)不僅結(jié)構(gòu)簡單，易于實現(xiàn)，而且也方便，價格便宜。它具有理論和實用價值。1. 緒論信號發(fā)生器可以作為信號源,它提供了一個已知的測試信號的電路。它可以用來測量感興趣的參數(shù)。在各種實驗測試應(yīng)用程序和處理中,信號源作為激勵源可以模擬各種測試信號,提供實際需要的電路1。信號發(fā)生器在通信技術(shù)中，電子測量儀器、電子電路、自動控制、雷達和其他電子系統(tǒng)中發(fā)揮非常重要的作用。隨著數(shù)字技術(shù)的飛速發(fā)展，出現(xiàn)了高精度數(shù)字-模擬轉(zhuǎn)換器，通過

3、使用多頻技術(shù)，這是DDS技術(shù)產(chǎn)生一個標準的參考頻率的數(shù)字控制方法2.任意波形信號發(fā)生器能夠滿足復(fù)雜的字段，用戶定義信號和計算機技術(shù)的結(jié)合，并使其更加精確和穩(wěn)定。隨著電子技術(shù)的發(fā)展現(xiàn)狀，該信號發(fā)生器具有很大的應(yīng)用。2. 系統(tǒng)我們設(shè)計了一個信號發(fā)生器,可以產(chǎn)生任意波形。我們可以控制振幅和頻率的大小,提供多種信號測試電路。利用AT89S52微控制器，AD9850(DDS)和數(shù)模轉(zhuǎn)換技術(shù)，完整的硬件和軟件設(shè)計。通過鍵盤輸入模塊，我們可以調(diào)整波形的振幅和頻率。波形生產(chǎn)的過程是通過微控制器來實現(xiàn)的。所以理論上我們可以編寫一個程序來生成任意所需的波形。單片機產(chǎn)生數(shù)字信號。為了獲得所需的波形，我們應(yīng)該有一個單

4、一的芯片變化的數(shù)字信號轉(zhuǎn)化為模擬信號。DDS芯片的AD9850是用來產(chǎn)生波形的。外部輸入的頻率數(shù)據(jù)可以通過簡單的并行或串行通訊接口與單片機轉(zhuǎn)化為芯片的頻率相位控制字。幅度調(diào)制是由AD7520芯片實現(xiàn)的。該系統(tǒng)的設(shè)計如圖1所示。該系統(tǒng)使用單片機控制DDS芯片AD9850產(chǎn)生儀器所需的測試的信號。單片機控制多路復(fù)用器。方波或正弦波DA轉(zhuǎn)換器AD7520的參考電壓信號。 AD7520的輸出信號，經(jīng)調(diào)節(jié)和放大之后，是一個15V的峰值頻率的信號。經(jīng)互補推挽放大電路后，我們終于得到必要的頻率信號。當負荷變化時，為了確保信號的穩(wěn)定性和頻率峰值，放大器電路中的放大器的輸出要加上適當?shù)呢摲答侇l率。3. 硬件該電

5、路的設(shè)計主要是兩個方面，包括硬件和軟件設(shè)計。硬件部分是信號生成電路，MCU（單片機）控制電路，振幅控制電路和顯示電路。軟件主要由主程序和中斷服務(wù)程序構(gòu)成。AT89S52是由美國ATMEL公司生產(chǎn)的，它是一個低電壓，高性能CMOS 8位微控制器芯片具有重復(fù)包含8K字節(jié)可擦除只讀閃存（Flash）程序存儲器和256字節(jié)的隨機存取數(shù)據(jù)存儲器。AT89S52可以操作到0 Hz靜態(tài)邏輯，支持兩種軟件可選的省電模式3。在本設(shè)計中，單片機是最重要的核心組成部分。其工作時間為12MHz。內(nèi)置閃存（flash）存儲的工作程序。通過鍵盤輸入，該電路可以知道需要產(chǎn)生的波形，振幅和頻率。我們還可以調(diào)整任何波形的振幅和

6、頻率。圖1. 系統(tǒng)方案在這個系統(tǒng)中，我們使用了一個獨立式鍵盤。該設(shè)計采用一個矩陣鍵盤，使用軟件掃描按鈕訪問必要的關(guān)鍵信息和用軟件編程實現(xiàn)。這樣可以節(jié)省硬件資源，簡化電路設(shè)計。通過矩陣鍵盤，我們可以很容易地設(shè)置各種微控制器。在這個設(shè)計中，P0端口連接液晶顯示器，AD9850和AD7520 IC芯片是用于數(shù)據(jù)傳輸?shù)逆溄?。因為原來的I/O端口是不夠的，我們需要在其他外設(shè)借口擴展微控制芯片。在這個電路中，我們使用8255芯片，這是一個可編程并行I/O接口芯片。高度集成的頻率合成器AD9850是一個典型的采用DDS技術(shù)的產(chǎn)品。AD9850采用先進的CMOS工藝。它的電源在3.3V時只有155mw。在擴展

7、工業(yè)溫度范圍為-40+80攝氏度，28引腳小外形封裝表面貼裝形式。AD9850 DDS系統(tǒng)包括可編程和高速比較器，全數(shù)字編程來實現(xiàn)頻率合成的控制。AD9850可以產(chǎn)生一個模擬正弦波輸出且是可編程控制的頻率和相位，連接到該精確時鐘和寫入的頻率。該正弦波的頻率信號，可直接用作源或內(nèi)部的高速比較器轉(zhuǎn)換為方波輸出.在125MHz的時鐘，32位頻率控制字AD9850可以輸出0.0291Hz的輸出頻率分辨率4。在這個電路設(shè)計中，從D0-D7是控制信號輸入到寄存器中。在W_CLK（P3.0）的上升沿的第一個字節(jié)加載和指針移動到下一個輸入寄存器。連續(xù)5上升沿，它停止工作。然后當上升沿FQ_UD（P3.1），數(shù)

8、據(jù)被加載到頻率/相位寄存器。在這個時候DDS的輸出頻率和相位更新。然后，指針重置電路等待下一個頻率/相位控制字的輸入。顯示模塊。考慮到實際情況，我們采用點陣LED實現(xiàn)顯示。LCD1602顯示輸出波形的平率、振幅以及特定類型。 LCD1602和8255芯片PA口相連。三個端子RS，RW，E分別連接在微控制器P2.7-P2.5。該軟件可以控制波形的顯示和波形頻率的類型。RS是一個選擇寄存器是選擇數(shù)據(jù)寄存器高，低，指令寄存器。RW為讀寫信號線，高為讀取、低為寫入操作。當RS和RW為低，液晶可以寫入指令或者顯示地址。當RS低和RW是高時，LCD可被讀取。當RS為低和高-RW時，液晶可以被寫入數(shù)據(jù)。 E

9、引腳是能源方面。當E引腳從高電平變?yōu)榈碗娖?，在LCD上執(zhí)行命令。AD9805輸出恒定的波幅度。我們使用一個D / A轉(zhuǎn)換器AD7520實現(xiàn)幅度的調(diào)整。AD7520芯片的內(nèi)部電阻網(wǎng)絡(luò)是由一個可編程可變增益放大器。AD7520集成了10個模擬開關(guān)的電阻網(wǎng)絡(luò)是可編程的。內(nèi)部電阻器網(wǎng)絡(luò)與AD7520可編程放大器被用作電路的增益5。倍率可以在1到1024之間調(diào)整，只要改變BIT1-BIT10相應(yīng)的邏輯狀態(tài)變化可以控制放大倍數(shù)。當BIT1-BIT10是3FFH，放大倍率為1倍，這為0dB。當是98H，放大率是10倍，這為20dB。為了實現(xiàn)可編程增益，我們連接的74LS373 PC端口和單片機的P2口與AD

10、7520引腳BIT1-BIT10。通過程序，微控制器控制I/ O口輸出狀態(tài)來完成可編程增益5。該系統(tǒng)需要一個5V直流電源提供給所有電路。直流電源一般由電源變壓器，整流器，濾波器電路和電壓調(diào)節(jié)器組成的。電力變壓器的作用是將220V交流電壓功率轉(zhuǎn)換為整流濾波電路所需的交流電壓。整流器的作用是將交流電壓轉(zhuǎn)換成直流電壓的單脈沖。濾波電路是濾除整流后的輸出電壓紋波。整流電路的輸出之后，波形仍含有大量的AC分量而會影響負載電路的正常運行。我們需要通過濾波電容器的紋波過濾。濾波電路是用電容濾波電路。固定輸出電壓調(diào)節(jié)部分選用三端集成穩(wěn)壓器。采用三端穩(wěn)壓器可以很容易地集成固定輸出電源集成形式。4. 軟件軟件采用

11、C語言編程并且不同功能模塊的程序是通過模塊化的程序設(shè)計思想實現(xiàn)的。這種結(jié)構(gòu)化方法使程序?qū)哟吻逦?，便于使用、維護和調(diào)試。該軟件設(shè)計完成的信號發(fā)生器的所有功能管理，由初始化模塊、功能模塊兩部分組成。初始化模塊是為各種硬件寄存器，數(shù)據(jù)寄存器，和顯示裝置的初始化。初始化模塊設(shè)計是由四個部分組成，微處理器的初始化，AD9850芯片的初始化，AD7520芯片的初始化和LCD1602的初始化。功能模塊是一個顯示模塊、鍵盤輸入模塊和信號調(diào)節(jié)模塊和振幅組件。鍵盤模塊主要是用于設(shè)置的頻率、相位和振幅。主系統(tǒng)的軟件編程方法使用結(jié)構(gòu)方法。該功能模塊由主程序分離和子程序產(chǎn)生的波形。延遲可以插入改變頻率。首先，我們進行了

12、微控制器，AD9850，AD7520和液晶顯示器的初始化。然后我們通過鍵盤選擇波形。頻率調(diào)節(jié)是通過AD9850芯片完成，波形振幅調(diào)制可以通過AD7520芯片來實現(xiàn)整個過程實現(xiàn)了以下功能：插上電源，液晶顯示器，然后循環(huán)。如果一個鍵被檢測到，它被暗示電路開始傳輸數(shù)字。程序繼續(xù)檢測鍵盤和不同的密鑰的控制具有不同的功能。只要信號生成模塊通過鍵盤控制輸出的幾個基本波形，AD9850芯片可以通過線性組合產(chǎn)生不同的波形具有不同的頻率。振幅是相對穩(wěn)定的。5. 結(jié)論所設(shè)計的信號發(fā)生器主要由單片機AT89S52，DDS芯片AD9850，AD7520芯片，顯示電路和濾波電路。單片機控制整個電路，由AD9850芯片產(chǎn)

13、生信號的頻率。信號通過濾波器電路濾波。在單片機AT98S52的控制下，AD7520芯片調(diào)制信號的振幅。我們可以通過顯示電路觀察信號的頻率和幅度。通過使用AD9850的芯片，使得具有相當高的穩(wěn)定性和產(chǎn)生的波非線性失真系數(shù)相對較小。該系統(tǒng)不僅結(jié)構(gòu)簡單，易于實現(xiàn)，而且也方便，價格便宜。它具有理論和實用價值。致謝這項工作是由中國國家自然科學(xué)基金（10904073號）資助。參考文獻1 萬雍倫，司強，盧有新，王學(xué)剛，超寬帶雷達信號產(chǎn)生技術(shù)的雙通道。信號處理，87卷，第12期，2007年，頁3101-3107。2 沃爾特凱斯特。直接數(shù)字頻率合成（DDS）。數(shù)據(jù)轉(zhuǎn)換手冊，2005年，頁677-691。3 孫華

14、，新ATMEL公司的AT89S52單片機及其應(yīng)用，2004年-北京：清華大學(xué)出版社。4 CMOS125MHz的完整的DDS 合成器AD9850。5 杰夫沃克杰拉德Ledwich。寬帶考慮多級轉(zhuǎn)換器 IEEE 電力電子產(chǎn)品，1999年,14（1）：110221105外文資料原文Design of An arbitrary waveform signal generator Xiao Chen and Jian xiang ChenSchool of Electronic and Information Engineering, Nanjing University of Information

15、Science and Technology, Nanjing 210044, ChinaAbstract Signal generator plays a very important role in communication, electronic measuring instruments, electronic circuits, automatic control, radar and other electronic systems. Direct Digital Synthesis (DDS) technology can easily control the frequenc

16、y of the signal for direct synthesis of waveforms. This paper designed a signal generator with the amplitude and frequency modulation by using AD9850 as frequency synthesizer and AT89S52 single chip microcomputer (SCM) as the core. Detailed design principle and idea are discussed. AD9850 of the DDS

17、chip is used to generate the waveform. The frequency data of external input can be transformed to frequency phase control words of chip by simple parallel or serial communication interface with the single chip microcomputer. Amplitude modulation is realized by the AD7520 chip. The system is not only

18、 simple in structure, easy to implement, but also convenient and cheap. It has a theoretical and practical value. 1.Introduction Signal generator can be used as a signal source, which provides a known test signal to the circuit. It can be used to measure parameters of interest. In a variety of exper

19、imental test applications and processing, the signal source as the excitation source can simulate a variety of test signals, providing the practical needs to the circuit 1. Signal generator play a very important role in communications, electronic measuring instruments, electronic circuits, automatic

20、 control, radar and other electronic systems. With the rapid development of digital technology, there has been high-precision digital-analog converter,digital control method by using a standard reference frequency generated by multiple frequency technology, which is the DDS technology 2. Arbitrary w

21、aveform signal generator can meet the complex fields, user-defined signal, and the combination of computer technology and make it more accurate and stable. With the current development of electronic technology, the signal generator has a great application. 2. System We designed a signal generator, w

22、hich can produce several arbitrary waveforms. We can control the size of amplitude and frequency, providing a variety of signals to the test circuit. Using AT89S52 micro controller, AD9850 (DDS) and digital-analog conversion technology, we complete hardware and software design. Through the keyboard

23、input module, we can adjust the amplitude and frequency of the waveform. Waveform generation process is achieved by the micro controller. So theoretically we can write a program to generate any desired waveform. SCM generates digital signal. In order to obtain the desired waveform, we should have a

24、single chip changing digital signals into analog signals. AD9850 of the DDS chip is used to generate the waveform. The frequency data of external input can be transformed to frequency phase control words of chip by simple parallel or serial communication interface with the single chip microcomputer.

25、 Amplitude modulation is realized by the AD7520 chip. The system design is shown in Fig. 1. The system uses SCM to control DDS chip AD9850 which produce the required signal for test instrument. SCM controls the multiplexer. The square wave or sine is DA converter AD7520s voltage reference signal. AD

26、7520s output signal, after conditioning and amplification, is a 15V peak frequency signal. After complementary push-pull amplifier circuit, we finally get the necessary frequency signals. To ensure the signal stability peak and frequency when the load changes, the amplifier circuit in the amplifier

27、outputs are added with the appropriate negative feedback. 3.Hardware The circuit design is mainly two aspects including hardware and software design. The hardware part is the signal generation circuit, MCU control circuit, amplitude control circuit and display circuit. Software is mainly composed of

28、 main program and interrupt routines. The core controller is AT89S52. ATMEL AT89S52 produced by the U.S. is a low-voltage, high performance CMOS 8 bit micro controller chip with repeated contains 8k byte erasable read-only Flash program memory and 256 bytes of random access data memory. AT89S52 can

29、operate down to 0Hz static logic to support two kinds of software-selectable power-saving mode 3. In this design, SCM is the most important core component. Its work time is 12MHz. The internal flash stores the working procedures. Through the keyboard input, the circuit can know what is required to g

30、enerate the waveform, the amplitude and frequency. We can also adjust any waveform of amplitude and frequency. Fig. 1. The system scheme In this system, we use an independent-type keyboard. The design uses a matrix keyboard, using the software scan button access to key information as necessary and a

31、chieving with software programming. This can save hardware resources, simplifying circuit design. By the matrix keyboard we can easily set on a variety of micro controllers. In this design, P0 port is connected with the LCD display, AD9850 and the AD7520 IC chip is for data transmission. Because the

32、 original I/O ports are not enough, we need micro controller chip on the expansion of other peripheral interfaces. In this circuit, we use the 8255 chip, which is a programmable parallel I/O interface chip. The highly integrated frequency synthesizer AD9850 is a typical use of DDS technology product

33、s. AD9850 uses advanced CMOS process. Its power supply is only 155mw at 3.3V. The extended industrial temperature range is from -40 to +80 centigrade degree with 28-pin Shrink Small Outline surface mount form. AD9850 DDS system includes programmable and high-speed comparators, all-digital programmin

34、g to achieve the control of frequency synthesis. AD9850 can produce a frequency and phase is programmable control of the analog sine wave output when connected to the precision clock and the frequency of write. The sine wave frequency signal can be directly used as the source or the internal convers

35、ion of high-speed comparator for the square wave output. In the 125MHz clock, the 32-bit frequency control word can AD9850 output frequency resolution of 0.0291Hz 4. In this circuit design, the control signal input from the D0-D7 into the register. In rising edge of W_CLK (P3.0) the first byte is lo

36、aded and the pointer moves to the next input register. A continuous 5 rising edge, it stops working. Then when the rising edge FQ_UD (P3.1), the data is loaded into the frequency/phase register. At this time the DDS output frequency and phase updates. Then the pointer reset and the circuit waits for

37、 the next frequency/phase control word input. Display Module. Considering the actual situation, we adopt dot matrix LED to realize the display. LCD1602 can display the output waveform frequency, amplitude, and the specific type. LCD1602 and the PA port of 8255 chip are connected. Three terminals RS,

38、 RW, E connected the P2.7-P2.5 of micro controller respectively. The software can control the type of waveform display and waveform frequency. RS is a register choice is to select the data register high, low, the instruction register. RW is the read write signal line, height is read, and write opera

39、tion is low. When the RS and RW are low, the LCD can be written instruction or display the address. When RS is low and RW is high, the LCD can be read. When RS is low and high-RW, the LCD can be written data. E pin is the energy side. When the E pin is from high to low, the LCD execute commands. AD9

40、805 outputs constant wave amplitude. We use a D/A converter AD7520 to achieve amplitude adjustment. The internal resistor network of AD7520 chip is composed of a programmable variable gain amplifier. AD7520 integrates the resistance network of 10 analog switches which are programmable. Internal resi

41、stor network with the AD7520 programmable amplifier are used as gain of the circuit 5. Magnification can be adjusted between 1 to 1024, as long as the change BIT1-BIT10 the corresponding bit changes logic state can control the magnification. When BIT1-BIT10 is 3FFH, the magnification is 1 time, whic

42、h is 0dB. When 98H, the magnification is10 times, which is 20dB. To realize Programmable gain, we connect PC port of 74LS373 and P2 port of SCM with AD7520 pin BIT1-BIT10. Through program, the micro controller control I/O port output state to complete the programmable gain 5. The system requires a 5

43、V DC power supply to all circuits. DC power supply is generally composed of power transformer, rectifier, filter circuit and the voltage regulator circuit. The role of power transformer is to transform 220V AC voltage power into AC voltage required by rectifier filter circuit. The role of rectifier

44、is to transform AC voltage into DC voltage single pulse. Filter circuit is to filter out the rectified output voltage ripple. After the rectification circuit output, the waveform still contains a large AC component which will affect the normal operation of the load circuit. We need to filter through

45、 the filter capacitor ripple. Filter circuit is with capacitor filter circuit.Fixed output voltage regulator part selects three-terminal integrated voltage regulator. The use of three terminal regulator can be easily integrated form of fixed output power supply. 4.Software The software design adopts

46、 C programming language and programs different functional modules by the modularization program design idea. This structured approach enables program-level clarity, ease of use, maintenance, and debugging. The software design completes management of all the features of the signal generator, the init

47、ialization module, and the function modules of two parts. Initialization module is for the various hardware registers, data registers, and display device initialization. Initialization module design is composed of four parts-the microprocessor initialization, AD9850 chip initialization, AD7520 chip

48、initialization and LCD1602 initialization. Function module is a display module, keyboard input module and signal conditioning modules and amplitude components. The keyboard module is mainly used to set the frequency, phase and amplitude. The main system software programming method uses the structura

49、l method. The function modules separate from the main program and subprograms generated waveforms. Delay can be inserted to change the frequency. Firstly, we perform the initialization of the micro controller, AD9850, AD7520 and LCD displays. Then we choose waveform by keyboard. The frequency adjust

50、ment is done through the AD9850 chip and the waveform amplitude modulation can be accomplished through the AD7520 chip. The entire process to achieve the following functions: plug in the power, the liquid crystal display, and then loop. If a key is detected, it is implied that data transmission circuit begins. The program continues to detect the keyboard and the control of different keys have different functions.As long as the signal gene