電子機(jī)電論文編號(hào):JD036  有答辯PPT  字?jǐn)?shù):12624,頁(yè)數(shù):39

                                              
                                                                              
目  錄
摘  要.................................................................. I
Abstract............................................................... II
1 緒論 .................................................................1
1.1 課題背景 ...........................................................1
1.2 鎖相技術(shù)發(fā)展概況 ...................................................1
1.3 鎖相技術(shù)的特點(diǎn) .....................................................2
1.4 頻率合成的方法..................................................... 2
2 鎖相環(huán)路和鎖相頻率合成器的基本原理 ...................................4
2.1 鎖相環(huán)基本原理 .....................................................4
2.2 鎖相頻率合成器的基本原理 ...........................................6
3 基于單片機(jī)的鎖相頻率合成器的設(shè)計(jì) .....................................7
3.1 系統(tǒng)簡(jiǎn)介........................................................... 7
3.2 方案的選擇......................................................... 7
3.2.1 集成鎖相環(huán)頻率合成器芯片的選擇 ...................................7
3.2.2 單片機(jī)部分的選擇 .................................................8
3.3 鎖相環(huán)路功能模塊電路的設(shè)計(jì)......................................... 8
3.3.1 壓控振蕩電路 .....................................................8
3.3.2 鎖相環(huán)電路....................................................... 9
3.3.3 鎖相環(huán)電路分析................................................... 11
3.4 單片機(jī)模塊的設(shè)計(jì) ...................................................12
3.4.1 單片機(jī)模塊的構(gòu)成及分析........................................... 12
3.4.2 顯示驅(qū)動(dòng)器CD4511................................................. 13
3.4.3 譯碼器74LS138 ....................................................14
3.4.4 單片機(jī)與鎖相環(huán)的連接 .............................................14
3.5 系統(tǒng)軟件設(shè)計(jì)....................................................... 14
4 系統(tǒng)功能調(diào)試 .........................................................18
4.1 壓控振蕩器的調(diào)試 ...................................................18
4.2 偉福仿真系統(tǒng)程序功能 ...............................................18
4.2.1 偉福軟件介紹 .....................................................18
4.2.2 用偉福調(diào)試系統(tǒng)程序 ...............................................18
4.3 鎖相環(huán)路的調(diào)試 .....................................................20
4.4 輸出頻率測(cè)量及穩(wěn)定度............................................... 21
5 結(jié)論................................................................. 22
致  謝................................................................. 23
參考文獻(xiàn)............................................................... 24

附錄I：系統(tǒng)程序 ........................................................25

摘  要
    隨著無(wú)線電技術(shù)的發(fā)展，對(duì)信號(hào)的頻率穩(wěn)定度和準(zhǔn)確度要求越來(lái)越高，一般振蕩器不能滿(mǎn)足要求，而高穩(wěn)定度的晶體振蕩器產(chǎn)生的頻率往往是單一的或者只能在極小的范圍內(nèi)微調(diào)，而且頻率通常都不很高。為了解決頻率穩(wěn)定度、準(zhǔn)確度和頻率高、寬范圍可調(diào)之間的矛盾，就需要頻率合成技術(shù)。其技術(shù)特點(diǎn)是將一個(gè)高穩(wěn)定度和高精度的標(biāo)準(zhǔn)頻率源經(jīng)過(guò)加、減、乘、除的四則運(yùn)算，產(chǎn)生同樣穩(wěn)定度和精度的大量離散頻率。
本系統(tǒng)主要分為頻率合成模塊和單片機(jī)模塊。單片機(jī)模塊包含單片機(jī)、鍵盤(pán)、LED顯示屏，主要控制系統(tǒng)的各種功能，頻率的合成及各種參數(shù)；頻率合成模塊包括與單片機(jī)連接的并行接口、頻率合成器、低通濾波器、壓控振蕩器。它可在一定范圍產(chǎn)生各種離散的頻率輸出，輸出范圍為36MHz-38MHz,頻率穩(wěn)定度。本文主要介紹了該系統(tǒng)的組成原理及設(shè)計(jì)過(guò)程，同時(shí)也闡述了設(shè)計(jì)過(guò)程中所遇到的問(wèn)題及解決方案。
關(guān)鍵詞: 單片機(jī)；鎖相環(huán)；頻率合成； 壓控振蕩；鑒相器 
Abstract：With the development of radio technology for signal frequency stability and accuracy for demanding high, the general oscillator can not meet the requirements and the high degree of stability arising from the crystal oscillator frequency are often single or only in the context of minimal fine-tuning, but the frequency is usually not very high. To address the frequency stability, accuracy and high frequency, wide scope of powers between the contradictions requires frequency synthetic technology. Their technical characteristics is a high stability frequency source for standard and high-precision through Canada, reduced, by, the mathematical operations, and have the same stability and accuracy for the large number of discrete frequencies.
   This system is divided into primarily the frequency synthesizes module and the MCU module. I mainly am responsible for the MCU module and the frequency synthesizes module of the system. The MCU module which includes the MCU, KB and LED display, mainly controls various functions of the system, the frequency synthesizes and various parameters. The range of output frequency is 36MHz-38MHz. The thesis mainly introduces the constitute principle of the system and the designing process and expatiates design problem met in process and solutions.
Key words: MCU ; PLL ; The frequency synthesizes ; VCO ; PD