self heterodyne

例句：

1. 1.The self-heterodyne receiver is used to detect the frequency of radio waves.
   自相关器用于检测无线电波的频率。
2. 2. In the self-heterodyne system, the signal is mixed with a local oscillator to produce a beat note.
   在自相关系统中，信号与本地振荡器混合产生拍音。
3. 3. The self-heterodyne receiver has become increasingly popular in modern communication systems.
   自相关接收器在现代通信系统中越来越受欢迎。