中心議題：

• 研究高頻小信號諧振放大電路時域與頻域分析

解決方案：

• 采用時域的分析方法
• 采用頻率分析方法

引言

zaitongxindianzidianluzhong，duiyuweixiaodexinhaoxuyaojinxingyidingzengyidefangda。tongxinzhongdeweixiaoxinhaodoushuyugaopinxinhao，suoyidianludefenxidoushijiyuqijiandefeixianxingtexingjinxingde。feixianxingdianludeshuchuzhongbutongpinlvfenliangdexinhaofenliangjiaoduo

，suoyixuyaocaiyongjuyoupinlvxuanzegongnengdexiezhenwangluojinxingpinlvdexuanze。xiezhenwangluopinlvxuanzedexingnengzhijiejuedinglexiezhenfangdadianludexingneng。caiyongshiyuboxingdeguanceyijipinyubutongpinlvdepinpujinxingduibifenxi，keyiqingxididuixiezhenfangdadianlujinxingfenxi。

1 諧振放大電路概述

諧振電路原理圖中的LC並聯諧振回路用電阻Rc代替，就是典型的共發射極電路。它的電壓放大倍數是Au=βRc／rbe(這裏是其絕對值，沒有考慮相位問題)。由於Rc對所有的頻率分量都呈現出相同的阻值(阻抗)
，故這個電路沒有頻率選擇作用(即在很寬的頻率範圍內，其放大倍數是一樣的)。若Rc用LC並bing聯lian諧xie振zhen回hui路lu代dai替ti
，由you於yu諧xie振zhen阻zu抗kang的de頻pin率lv特te性xing，使shi得de在zai諧xie振zhen頻pin率lv點dian及ji左zuo右you極ji小xiao的de頻pin率lv範fan圍wei內nei呈cheng現xian出chu很hen高gao的de阻zu抗kang，使shi電dian路lu的de電dian壓ya放fang大da倍bei數shu很hen高gao，而er離li開kai諧xie振zhen點dian的de其qi他ta頻pin率lv範fan圍wei都dou呈cheng現xian出chu極ji低di的de阻zu抗kang(理想狀態下可以看做為零)
，使電壓放大倍數接近於零，於是這個放大器就有了對某一頻率有選擇性的放大特性，稱為諧振放大器。 2 小信號諧振放大電路的時域分析
[page] 在測試電路中
，高頻小信號選擇6MHz
、50mV的正弦波信號，示波器同時測試輸入與輸出兩路信號的波形。輸入輸出波形如圖3所示。

3 小信號諧振放大電路的時域分析

zaipinyufenxizhongjiushiyipinlvzuoweifenxidebianliang，fenxixinhaozhongbutongdepinlvfenlianggoucheng。zaipinlvfenxizhong
，jiaoweizhongyaodegainianjiushidianludetongpindaiyuxuanzexing，zuoweixiezhenfangdadianluyifangmianyaotongguosuoxudepinlvchengfen，yinerduiqijuyoutongpindaideyaoqiu，lingyifangmian，yaoyizhibuxuyaodexinhaodepinlvchengfen，zhezhongtongguoyouxiaochengfenyizhiwuxiaochengfendexingzhichengweixuanzexing。danzaishijiyingyongzhongwangwangyaoqiutongpindaiyineichuanshuxishujinkenengda，tongpindaiyiwaichuanshuxishujinkenengxiao
，zheyangxinhaoshizhenxiao，yizhiganraonengliqiang，youcikejiantongpindaiyuxuanzexingxiangmaodun，guyongjuxingxishuK0．1說明。理想諧振放大器的頻率特性曲線，其矩形係數K0.1應等於1，實際的諧振放大器的矩形係數總是大於1的。應用軟件的傅裏葉分析的頻譜圖如圖4所示。 4 小結

zaiduidianzixianludexingnengfenxizhong

，caiyongshiyudefenxifangfabijiaojiandanzhijie，nenggouzhiguanfenxidianludeshurushuchu，yijigegeceshidiandeboxing。danshishiyufenxibunengquedingdianluduiyubutongpinlvdexiangying，yewufazhunquelejiebutongpinlvdexinhaoduidianludeganrao。pinlvfenxiweifenxipinlvduidianludeyingxiangtigonglezhijiedefangfa

，zaiduixiandaidianzixianludefenxizhong，fahuileyuelaiyuedadezuoyong。