We all use antennas for radios, cell phones, and WiFi. Understanding how they work, though, can take a lifetime of study. If you are rusty on the basic physics of why an antenna radiates, have a look at the very nice animations from [Learn Engineering] below.
The video starts with a little history. Then it talks about charges and the field around them. If the charge moves at a constant speed, it also has a constant electric field around it. However, if the charge accelerates or decelerates, the field has to change. But the field doesn’t change everywhere simultaneously.
Where the field changes, there is a kink in the electric field. That kink explains the radiation. From that idea, the video builds to dipole antennas and more. Watching this video won’t get you ready to design the next broadband log periodic antenna, but it will help you get more of a gut feel for how antennas work.
This is one of those topics that is tough to approach even with sophisticated math. We’ve looked at other videos on the topic. We are pretty sure this is one of those topics that is much harder to learn without animations.