directional frequency modulation

例句：

1. 1. The directional frequency modulation (DFM) system is designed to enhance the signal-to-noise ratio in a wireless communication system.
   定向频率调制系统旨在提高无线通信系统中的信号与噪声比。
2. 2. In DFM, the transmitter sends signals that are encoded with information about the direction of thedesired signal.
   在定向频率调制中，发射器发送带有所需信号方向信息的编码信号。
3. 3. The DFM technique has been widely used in radar systems for its ability to focus the transmitted energy on specific targets.
   定向频率调制技术在雷达系统中被广泛应用，因为它能够将发射能量聚焦在特定目标上。