摘要


頻率合成是以一個或少量的高準確度和高穩(wěn)定度的標準頻率作為參考頻率，由此導(dǎo)出多個或大量的輸出頻率，這些輸出的準確度與穩(wěn)定度與參考頻率是一致的。在通信、雷達、測控、儀器表等電子系統(tǒng)中有廣泛的應(yīng)用，
頻率合成器有直接式頻率合成器、直接數(shù)字式頻率合成器及鎖相頻率合成器三種基本模式，前兩種屬于開環(huán)系統(tǒng)，因此是有頻率轉(zhuǎn)換時間短，分辨率較高等優(yōu)點，而鎖相頻率合成器是一種閉環(huán)系統(tǒng)，其頻率轉(zhuǎn)換時間和分辨率均不如前兩種好，但其結(jié)構(gòu)簡單，成本低。并且輸出頻率的準確度不遜色與前兩種，因此采用鎖相頻率合成。

關(guān)鍵詞: 鎖相 頻率合成器

















ABSTTRAC

Frequency synthesis is based on one or a small quantity of high accuracy and high stability of standard frequency as reference frequency ,Which lead to more or a lot of output frequency,The output accuracy and stability is consistent with the reference frequency.In communication,radar, monitoring,instrument table and other electronic systems have the widespread application .
Frequency synthesizer have three basic modes,which are direct type frequency synthesizer, direct digital frequency synthesizer and phase-locked frequency synthesizer.The first two are the open-loop system.Therefore, the advantages are that frequency conversion time is short and higher resolution.The phase-locked frequency synthesizer is a close-loop system,its frequency conversion time and resolution are lower than the first two ,however, it is not only simple structure ,low cost but also output frequency accuracy is not less than the first two.So we adopt phase-locked frequency synthesizer.
Keywords: phase-locked Frequency synthesizer











目錄
第一章 緒論.........................................................1

1.1 引言.........................................................1

1.2 頻率合成的技術(shù)指標...........................................1

1.3 頻率合成器的類型.............................................3

1,4 DDS和PLL合成技術(shù)............................................8

第二章 鎖相環(huán).......................................................11

2.1 鎖相環(huán)的基本工作原理.........................................11

2.2 鎖相環(huán)的基本環(huán)路方程.........................................12

2.2.1 鑒相器................................................12

2.2.2 環(huán)路濾波器............................................14

2.2.3 壓控振蕩器............................................15

第三章 基于CD4046的鎖相環(huán)頻率合成器的設(shè)計.........................17

3.1 鎖相環(huán)頻率合成器的原理.......................................17

3.2 集成鎖相環(huán)CD4046介紹........................................17

3.3 N分頻的設(shè)計..................................................21

3.4 1KHz標準信號源的設(shè)計.........................................22

3.5 鎖相環(huán)參數(shù)的設(shè)計.............................................24

第四章 Proteus軟件介紹及其仿真.....................................25

4.1 Proteus概述................................................25

4.1.1 Proteus的功能特點..................................25

4.1.2 Proteus的電路功能仿真...............................26

4.2 Proteus仿真................................................26

第五章 焊接與調(diào)試..................................................31

第六章 實驗總結(jié)....................................................33

致謝...............................................................35

參考文獻...........................................................37