up-conversion

例句：

1. 1. The device canperform up-conversion to convert the signal frequency.
   该设备可以执行向上转换，以转换信号频率。
2. 2. In the process of up-conversion, the energy is converted into another form.
   在向上转换过程中，能量被转换成另一种形式。
3. 3.Up-conversion technology has been widely used in communication systems.
   向上转换技术已被广泛应用于通信系统中。