1Create carrier：谐振器，如433.92Mhz LC谐振 (频偏控制）
2Add data to carrier 加载数据
3Amplify to broadcast ：放大器，如NPN三极管射级电路
baseband processor：把信息数字化-变成二进制（编程定义）
modulator:调制电路
Antenna:标准天线
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The simplest radio receiver we can make is called a homodyne receiver。
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superheterodyne receiver
解调模块
