本设计根据锁相环原理，通过两片CD4046搭接基本电路来实现FM调制/解调电路的设计，将调制电路的输出信号作为解调电路的输入信号，最终实现信号的调制解调。原理分析，我们得到的载波信号的电压 大于3V，最大频率偏移 5KHz，解调电路输出的FM调制信号的电压 大于200mV可以看出我们的具体设计符合设计指-The design phase locked loop principle, by two overlapping basic circuit to achieve CD4046 FM modulation/demodulation circuit design, the modulation circuit output signal as an input signal demodulation circuit, and ultimately the modem signal. Principle of the voltage of the carrier signal we get is more than 3V, the maximum frequency deviation 5KHz, the output of the FM demodulation circuit voltage modulation signal is larger than 200mV can see that we comply with the design refers to the specific design