Electromagnetic radiations in our mordern communication

You might have seen how the communiction system is growing now a days. There was a rapid change in it which even now doesn't seems to stop. Thats fine but do you know how communication now a day works,its not like old analog cable. These analog cables are replaced by unvisible,undisturbable electromagnetic waves. You may know that there is a magnetic field around the earth,in that some if you pass some electric signal the pushes each other and and travell in the air for long distance,even the quality is also high. The question araising is how to add electric field in air,its actualy uses series of LCR circuit. Our massage is inserted in these waves as change in frequency or the phase of this wave. This has strengthen the mordern communication system. The electromagnetic radiations are divident to some types depending on their characteristics. These waves are also used for many other purpose like medical field,researches etc.