1934_接收機(jī)增益自動(dòng)控制電路的設(shè)計(jì)

1934_接收機(jī)增益自動(dòng)控制電路的設(shè)計(jì),接收機(jī),增益,自動(dòng)控制,電路,設(shè)計(jì) 黃 河 科 技 學(xué) 院 畢 業(yè) 設(shè) 計(jì) 說(shuō) 明 書(shū) 第 I 頁(yè)接收機(jī)增益自動(dòng)控制電路的設(shè)計(jì)摘 要自動(dòng)增益控制電路已廣泛用于各種接收機(jī)、錄音機(jī)和信號(hào)采集系統(tǒng)中，另外在光纖通信、微波通信、衛(wèi)星通信等通信系統(tǒng)以及雷達(dá)、廣播電視系統(tǒng)中也得到了廣泛的應(yīng)用。本課題主要研究應(yīng)用于無(wú)線接收機(jī)的前級(jí)電壓放大，因此設(shè)計(jì)的電路需容納的頻帶范圍應(yīng)較寬，以至于使語(yǔ)音信號(hào)通過(guò)。由于信號(hào)的脈沖寬度是 0.3 微秒，重復(fù)頻率1.875 千赫茲，幅度波動(dòng)范圍是 1.5-3.0 伏，電路應(yīng)該實(shí)現(xiàn)增益的閉環(huán)調(diào)節(jié)，通過(guò)此電路可以實(shí)現(xiàn)增益的自動(dòng)調(diào)整，以至于使視頻信號(hào)強(qiáng)時(shí)自動(dòng)減小放大器的倍數(shù)，信號(hào)弱時(shí)自動(dòng)增大放大器的倍數(shù)，從而實(shí)現(xiàn)信號(hào)的自動(dòng)調(diào)節(jié)。本課題介紹了自動(dòng)增益控制的概念原理以及對(duì)自動(dòng)增益控制放大器各部分的工作原理，最后對(duì)系統(tǒng)的測(cè)試結(jié)果以及設(shè)計(jì)與實(shí)現(xiàn)中應(yīng)該注意的問(wèn)題也做了詳細(xì)分析。關(guān)鍵詞： 放大器；自動(dòng)增益控制； 電壓跟隨器； 濾波器黃 河 科 技 學(xué) 院 畢 業(yè) 設(shè) 計(jì) 說(shuō) 明 書(shū) 第 II 頁(yè)The design of receiver automatic gain control electric circuitAuthor:Xia Jian xin Tutor:Wang Fei AbstractThe automatic gain control electric circuit has been widely used in all kinds of receivers、tape recorders and signal gathering systems, and also been used in communications system radar, the broadcast television system and optical fiber communications, microwave communications, satellite communications.This topic mainly studies to the applies to the front level voltage amplification of the audio frequency amplification, therefore the frequency band scope of the electric circuit should be wider that can make the pronunciation signals to pass. Because the frequency band scope of the pronunciation signal is 0.3 microseconds, so the frequency band scope of our electric circuit should be designed within 1.875 KHz. And the electric circuit should realize the closed loop adjustment between 1.5 volt and 3.0 volt which increases, it may realize the automatic control through this electric circuit which increases when the tonic train signal is strong automatically that it can reduce the multiple of the amplifier, and when the signal is weak that it can automatically increase the multiple of the amplifier , so that can realize the volume with automatic control.This topic also introduced in the concept principle of the automatic gain control as well as to automatically increases the amplifier every part of principle of work the detailed introduction, and it pays attention to the question to the test result of this system .Finally we have make some analysis to the design.Key words：Amplifier； Automatic Gain Control； Voltage follower；Filter 黃 河 科 技 學(xué) 院 畢 業(yè) 設(shè) 計(jì) 說(shuō) 明 書(shū) 第 III 頁(yè)目 錄緒論 ………………………………………………………………………………………..11 自動(dòng)增益控制………………………………………………………………………………11.1 自動(dòng)增益控制電路（AGC）存在的意義 ......………………………………………..11.2 自動(dòng)增益控制的基本概念…………………………………………………………......21.3 自動(dòng)增益控制的原理 …………………………………………………………………31.4 自動(dòng)增益控制放大器…………………………………………………………………..41.5 本課題的研究?jī)?nèi)容 ………………………………………………………………...52 自動(dòng)控制電路增益的計(jì)算…………………………………………………………………62.1 自動(dòng)控制增益計(jì)算 …………………………………………………………………..62.2 主要性能指標(biāo)………………………………………………………………………….72.3 電路類(lèi)型……………………………………………………………………………….92.4 可控制增益放大器……………………………………………………………………103 自動(dòng)增益控制放大器的電路設(shè)計(jì) ………………………………………………………143.1 電路原理圖 …………………………………………………………………………..143.2 電路元器件選擇………………………………………………………………………144 輸出信號(hào)波形圖…………………………………………………………………………...214.1 主放大器基本原理……………………………………………………………………214.2 主放大器………………………………………………………………………………214.3 自動(dòng)頻率控制電路（907、928 組合）………………………………………………284.4 波形圖…………………………………………………………………………………29結(jié)論………………………………………………………………………………………….31致謝 ………………………………………………………………………………………….32參考文獻(xiàn)……………………………………………………………………………………..34