十九世纪末叶,科学家们从电磁波理论的证实到无线电波在通信中的应用,从电子发射现象的观察到电子荷质比的测量都标志着近代无线电电子学的开端.随着二十世纪初期真空二极管及三极管的问世以及电离层的发现,既为年轻的无线电通信技术开辟了新的纪元,又为电子器件的研制开拓了广阔的境地. 在二十世纪最初的四十年内,无线电通信和广播有蓬勃的发展,使用的无线电波波长,由长波进入中波、短波;传播距离由几十公里扩展到几百、几千公里;各种电子管、离子管、电子束管的陆续出现促使无线电技术的不断发展;而无线电理论的日趋完善又促使电子器件和电子设备的应用范围日益扩大.在第二次世界大战前夕,很多迹象表明所谓无线电技术已不再为 The end of the nineteenth century, scientists from electromagnetic wave theory confirmed to radio waves in communication, from the observation of the phenomenon of electron emission to measure the electronic charge-mass ratio marks the beginning of modern radio electronics .As the early twentieth century The advent of vacuum diodes and triodes, as well as the discovery of the ionosphere, opened up a new era for young radiocommunication and opened up a new horizon for the development of electronic devices.In the first four decades of the twentieth century, radiocommunications and The vigorous development of radio, the use of radio wave wavelength, by the longwave into the wave, shortwave; propagation distance from tens of kilometers to hundreds, thousands of kilometers; a variety of tubes, ion tubes, electron beam tube appears to promote the radio Technology continues to evolve; and the ever-improving radio theory has led to a growing range of applications of electronic devices and electronic devices. On the eve of the Second World War, there are many signs that the so-called radio technology is no longer