【正文】 列集成電路芯片組成數(shù)字鎖相頻率合成器，通過單片機(jī) AT89S52 控制分頻數(shù)，同時通過液晶顯示器向用戶反饋信息。 本次設(shè)計采用變模鎖相頻率合成技術(shù)產(chǎn)生所需要的頻率信號。第四部分介紹了用到的芯片。該設(shè)計以高頻信號源系統(tǒng)為研究目標(biāo)，從問題的提出到方案的確定，從鎖相環(huán)路的原理、應(yīng)用和數(shù)學(xué)模型分析到利用鎖相環(huán)路構(gòu)建高頻合成電路，軟、硬件實(shí)現(xiàn)。 而 VCO 作為其中一個必不可少的重要部件 ,其質(zhì)量可以左右整個環(huán)路的性能。 國內(nèi)外研究現(xiàn)狀 鎖 相技術(shù)起源于二十世紀(jì) 30 年代，提出無線電調(diào)幅信號的鎖相同步檢波技術(shù)；40 年代電視技術(shù)得到發(fā)展； 50 年代空間技術(shù)的發(fā)展； 60 年代相繼研究制出集成鎖相環(huán)部件和單片機(jī)鎖相環(huán)路； 70 年代由于半導(dǎo)體和集成電路技術(shù)的飛速發(fā)展，使鎖相技術(shù)越來越廣泛的應(yīng)用于電子技術(shù)領(lǐng)域； 80 至 90 年 代鎖相環(huán)路理論與研究日益完善，應(yīng)用范圍遍及整個電子技術(shù)領(lǐng)域。 近年來，鎖相技術(shù)在通信、航天、測量、電視、原子能等領(lǐng)域，能夠高性能地完成信號的提取，信號的跟蹤與同步，模擬和數(shù)字通信的調(diào)制與解調(diào)、頻率合成、濾波等功能，已經(jīng)成為電子 設(shè)備中常用的基本部件之一。 關(guān)鍵詞： MC1648； 鎖相環(huán) ； 頻率合成器 II Abstract The frequency synthesizer with high accuracy and high stability of the standard frequency of one or a few as the reference frequency, which leads to multiple or large amount of output frequency, accuracy and stability of the output and the reference frequency is consistent. There are widely applied in munication, radar, measurement and control, instruments and other electronic systems. Frequency synthesizer has the direct frequency synthesizer, DDS and PLL frequency synthesizer in three basic models, the former two belongs to the open loop system, so there is short frequency conversion time, resolution is higher, and the PLL frequency synthesizer is a closed loop system, the frequency conversion time and resolution is not as good as the first two good, but it has the advantages of simple structure, low cost. And the output frequency accuracy inferior to the former two, thus PLL frequency synthesis has been widely applied. VCO is one of the essential ponents, the performance of quality around the whole loop. Negative resistance integrated LCVCO because of the high operating frequency, a good waveform, frequency stability, low phase noise, high performance and reliable, suitable for VHF and UHF VCO. Therefore the PLL frequency synthesis based on MC1648. Key words： MC1648； PLL Frequency ； Synthesizer III 目 錄 1 緒論 ................................................................................................................................ 1 研究背景和意義 ...................................................................................................... 1 國內(nèi)外研究現(xiàn)狀 ...................................................................................................... 1 研究主要內(nèi)容和結(jié)構(gòu)安排 ...................................................................................... 1 2 系統(tǒng)方案設(shè)計 ................................................................................................................ 3 方案設(shè)計思想 .......................................................................................................... 3 方案設(shè)計方法 .......................................................................................................... 3 3 鎖相環(huán)及頻率合成器 .................................................................................................... 3 鎖相環(huán)的結(jié)構(gòu)及基本原理 ....................................................................................... 4 鎖相環(huán)路的各部件及其數(shù)學(xué)模型 ........................................................................... 5 鑒相器 ................................................................................................................ 5 環(huán)路濾波器 ........................................................................................................ 6 壓控振蕩器 ........................................................................................................ 6 環(huán)路相位模型和基本方程 ................................................................................ 7 頻率合成器及其技術(shù)指標(biāo) ....................................................................................... 8 頻率范圍 ............................................................................................................ 8 ............................................................................ 9 頻率轉(zhuǎn)換時間 .................................................................................................... 9 準(zhǔn)確度與頻率穩(wěn)定度 ........................................................................................ 9 4 芯片的介紹 .................................................................................................................. 10 AT89S52 單片機(jī) ..................................................................................................... 10 芯片 MC14515 MC1202 MC1648 簡介 ..................................................... 13 5 系統(tǒng)各單元電路設(shè)計 ................................................................................................... 16 壓控振蕩電路設(shè)計 ................................................................................................. 16 頻率合成器的設(shè)計 ................................................................................................. 19 環(huán)路濾波器 ............................................................................................................. 24 控制電路設(shè)計和頻率計算 ..................................................................................... 25 IV 6 軟件設(shè)計 .................................................................................................................... 27 MC145152 的控制和顯示部分的程序設(shè)計 .......................................................... 27 74LS595 的控制程序設(shè)計 ..................................................................................... 27 液晶顯示驅(qū)動的程序設(shè)計 .................................................................................... 28 7 總結(jié)與展望 ................................................................................................................ 29 參考文獻(xiàn) .......................................................................................................................... 30 致謝 .................................................................................................................................. 31 附錄 1 總體電路圖 ......................................................................................................... 32 附