Q: What is a Yagi?
A: The Yagi antenna is credited to Hidetsugu Yagi (although not the original inventor), A Japanese physicist. The Yagi was designed to improve the gain of the antenna concentrated in one direction. The directivity is accomplished with added elements called directors and reflectors. The Yagi has high Gain, is very directional, and has a narrow bandwidth. In simple unidirectional antennas like the Yagi, frequency bandwidth is inversely proportional to antenna gain. One way to increase the frequency bandwidth of a simple antenna like a Yagi is to increase the diameter of the antenna conductors. The greater the conductor diameter, the wider the band with increased conductor diameter also has a second benefit, it increases the physical strength of the antennas.