emitter

例句：

1. 1.The radio is an emitter of sound waves.
   收音机是一种声波发射器。
2. 2. The light bulb is the emitter of light in a room.
   灯泡是房间内光的发射器。
3. 3.The electron beam is an emitter of X-rays.
   电子束是一种X射线发射器。