自广播电视技术发明以来,其发射设备不断更新换代,发射功率不断提高,发射效果不断改善,广播电视覆盖面越来越大。在这个发展过程中,电子管起着举足轻重的作用。但是,电子管发射设备有很多先天不足,如热损耗大,效率低,体积大,工作状态不稳定,维护量大等。 Since the invention of radio and television technology, its transmitting equipment has been continuously updated, the transmitting power has been continuously improved, the transmitting effect has been continuously improved, and the broadcasting and television coverage has been growing. In this development process, the tube plays a decisive role. However, there are many inherent disadvantages of electron tube emitting devices, such as large heat loss, low efficiency, large volume, unstable working condition and large maintenance volume.