调频无线话筒的设计论文(1).docVIP

PAGE PAGE I 摘 要 对于整个录音音响系统中，第一个重要环节是话筒。话筒的重要性是人们时常谈论的话题。话筒的争论往往是最激烈而革命性的，从电子管到晶体管、从动圈到电容、从微型话筒到金话筒，还有值得珍藏的纪念版话筒等。话筒又分为有线话筒和无线话筒。调频无线话筒系统简单、成本低廉，但是采用传统制作方式做出的话筒音质不好且功能单一。市面上无线话筒产品的种类很多,高档的价格比较昂贵,低档的性能不太稳定。 调频无线话筒的原理是将声波信号通过麦克风转化为音频电信号，通过改变结电容来改变高频振荡器的输出频率，产生调频波，通过高频放大与选频，最终由天线辐射。整个电路使用Protel 99 se 软件设计，并最终做成一块8cm*4cm(width*height)PCB(印刷电路板)，使用普通调频收音机在100M频率左右，话筒中心20米范围内能正常接收。该设计具有电压低，受话灵敏，制作简易等特点，可应用于教学，无线广播，报警器，助听器，及各类声控设备中。 关键词 调频；三点式；振荡电路；载波；印刷电路板 Abstract The principle of frequency adjustment wireless radio microphone is that the signal changes sound wave into VF electric signal by the microphone , the wave exporting frequency , producing frequency adjustment by changing a HF oscillators coming changing the junction capacity, passes high-frequency amplification and chooses frequency , ultimate reason air wire radiation. The entire circuit is designed by using Protel 99 se software, makes up into a piece of 8 cm * 4 cm (width × high) PCB (printing circuit board ultimately), use the average frequency adjustment radio to be able to admit regularly in 100 M frequency retinue , 20 meters of microphone centre range inner. Its making process is not difficult and having an electricity being lowered ,for its characteristic , it can easily to applied into teaching , wireless broadcasting , alarm equipments, deaf-aid, and of all kinds sound control equipments. Key words: Frequency adjustment, trikini , oscillating circuit , carrier wave , printing circuit board. 目 录 第1章 绪论…………………………………………………………………2 HYPERLINK \l _第4章__设计方案第2章 设计方案…………………………………………………………3 HYPERLINK \l _4.1__电容三点式2.1 方案选择………………………………………………………3 HYPERLINK \l _2.2__无线话筒准用的频段2.2 无线话筒准用的频段………………………………………………4 HYPERLINK \l _5.2___各频段无线电波的传播特性2.3 各频段无线电波的传播特性………………………………………5 HYPERLINK \l _第3章__电路设计第3章 电路设计……………………………………………………………6 HYPERLINK \l _3.1__发射部分电路设计3.1 发射部分电路设计………………………………………………6 HYPERLINK \l _3.2_接收部分电路设计3.2 接收部分电路设计……………………………………………8 HYPERLINK \l _第七章__电路调整与改进第4章 电路调整与改进…………………………………………………11