基于PLL芯片的FSK调制解调模块电路文案最终文案.docVIP

摘 要 作为信道编码器的FSK调制解调器在现代通信系统中有着重要的地位，而基于PLL进行FSK信号的调制解调又有着非常多的优点，所以在实际应用中有着很大意义。本文介绍了一种基于锁相环的频移键控FSK信号调制解调电路的设计。在信号的收发两端均采用锁相环芯片CD4046。发送端采用锁相环芯片实现了基带信号的FSK调制，接收端采用CD4046芯片进行解调，并采用了低通滤波电路和电压比较器电路恢复出其基带信号。在本文中同时还介绍了设计和调试的具体过程，思路，选用器件的原因以及所用器件的工作原理和在本次设计过程中实际的应用效果，在本文最后也给出了本次设计的最终调试结果。基带信号通过以CD4046为核心的调制电路后成功的对基带信号进行了调制。同时，调制信号通过同样以CD4046为核心的带有有源低通滤波电路和电压比较电路的解调模块后被成功的解调出来。该电路具有结构简单，工作可靠，误码率低，成本低廉，易于实现等优点。通过对该电路的设计，可以加深对数字频移键控的的调制与解调的理解，同时还可以更加深入的学习了锁相环的原理和锁相环的应用。 关键词：PLL；FSK ；锁相环；频移键控；调制解调 ABSTRACT FSK modems,a channel of the encoder, has an important position in modern communication system ，and FSK demodulation based on the signal for PLL have many great advantages, so it has a great practical significance.This paper describes a method of FSK modem.Adopting the cheap phase-locked loop chip CD4046 at both the sending end and the receiving end.The low pass filtercircuit and the voltage comperator circuit are used to recover their baseband signal.This paper also introduces the specific process, ideas of the design and commissioning, the reason of the choosed device,the work principle and actual application effect of the devices used in the design process .At the last of the paper, final test results is also given .Baseband signal go through the modulation circuit whose core is CD4046, we can achieve the success of baseband signals modulation.At the same time, modulation signal go through the module demodulation part with a low pass filter circuit and the voltage comparison circuit ,it can be demodulated out successfully.This kind of circuit has the advantage of simple structure,cheap cost,being reliable work,low bit error rate and to be easy realizated.By designing the circuit,the better understanding of the digital frequency shift keying modulation and demodulation of the understanding of the way;more indepth study of the principle of phase-locked loop and phase-locked loop applications. Key words：PLL; FSK; phase-locked loop; frequency-shift keyi