“Yagi Antenna” is used all over the world and was invented by Hidetsugu Yagi and Shintaro Uda at Tohoku University 30 years after the start of the wireless communication age, which was at the end of the 19th century.
In 1895, Marconi in Italy succeeded in the experimentation on radiotelegraphy for the first time in the world. In 1920, the first radio public broadcasting in the world began in the United States, and five years after that, the first radio broadcasting in Japan started. The wavelength of radio at that time was medium wave (AM) only, as shortwave broadcasting had not started, and ultrashort waves (FM) and microwave (VHF, UHF) were far from practical use.
Hidetsugu Yagi, a professor in the Department of Engineering at Tohoku University, was researching ultrashort waves and in 1925, discovered that electric waves can be strongly received under a certain condition. With the help of Shintaro Uda of Yagi laboratory, he invented the antenna for ultrashort waves.
However, the technology generated little evaluation from the academic society in Japan, but received high acclaim in foreign countries. Radar was developed by using the Yagi Antenna technology in the United States and Europe. Still, Japan didn’t see this importance and even rejected the extension application for a patent, believing there is little practical use and necessity. It is said that this greatly affected the progress of World War II.
It was in 1942, when the Japanese army that occupied Singapore confiscated radar devices and technological notes and found the character “YAGI” written in the notes, that Japan recognized the importance of the Yagi Antenna.
After the war, television broadcasting began in every country. The Yagi Antenna spread all over the world as a television antenna.
In this 21st century, satellite broadcasting has spread together with a change to digital. Yet, Yagi Antenna is being used all over the world as a receiving antenna for television.