A Yagi–Uda antenna, commonly known as a Yagi antenna, is a directional antenna
consisting of multiple parallel elements in a line, usually half-wave dipoles
made of metal rods. Yagi–Uda antennas consist of a single driven element
connected to the transmitter or receiver with a transmission line, and
additional "parasitic elements" which are not connected to the transmitter
or receiver: a so-called reflector and one or more directors. It was
invented in 1926 by Shintaro Uda of Tohoku Imperial University, Japan, and
(with a lesser role played by his colleague) Hidetsugu Yagi.
Hidetsugu Yagi holding his famous Yagi-Uda design of radio antenna, which he co-developed with Shintaro Uda in the 1920s at Tohoku Imperial University in Japan.
This is buried in the Acknowledgements section and can easily be missed.
Yagi Calculator is a program to assist with the design of long yagi antennas. It uses the graphs and principles developed by DL6WU and printed originally in the German Radio Magazine VHF Communications (March 1982). The article was titled Extremely Long Yagi Antennas. For best front to back ratio it is recommended that a yagi be constructed with one of the following numbers of elements - 10,14,19,24. Yagi builders are reminded that DL6WU designs are primarily for long yagis. A boom length of 2 wavelengths (or 10 elements) would be a minimum sized antenna. On the other hand, yagis with as few as 8 elements have used the design and worked very well.
Download the windows program, SetupYagiCalculator.exe from John Drew's site. It runs under wine without any issues on my Ubuntu Version 18.04.
An excellent resource for building Yagi Antennas is The Welshman, G0KSC. His website can be found here: Free Yagi Antenna Designs for Ham Radio:
Folded Dipoles for VHF/UHF Yagis: