If two days ago we were memorizing John Logie Baird who demonstrated mechanical television (televisor) firstly, today we are memorizing Hidetsugu Yagi who invented antenna. With its special shape, the Yagi antenna gave the real effect to help the receiver get the stronger signals from a specific direction. This antenna helps to avoid the interference from other signals. So that, we can watch television and radio programs clearly. Hidetsugu Yagi was an electrical engineer. He developed and spread the technology of this antenna with his colleague, Shintaro Uda. That’s why, their developed antenna called as Yagi-Uda antenna. Nowadays, although most of us already use satellite television service, but the benefit of Yagi-Uda antenna still clear in our memory. Sometimes, we need to rotate it in order to receive the more clear image. Even today, maybe one or two of your neighbors still use this Yagi-Uda antenna. Or even in your own roof?