自从1895年伟大的俄国科学家亚·斯·波波夫发明世界上第一台无线电接收机以来,到现在已是100多年了。在此期间,无线电这门学科有了非常迅速的发展。无线电不仅可以用来传送电报,而且还可以播送声音和图像,还可以传送遥控、雷达、导航等等信号。收音机则是接收声音广播的一种无 More than 100 years have passed since the great Russian scientist Adam Popov invented the world’s first radio receiver in 1895. During this period, there was a very rapid development in the radio discipline. Not only radio can be used to send telegraphy, but also can broadcast sound and images, but also can send remote control, radar, navigation and so on signal. The radio is a type of radio reception