This article is a stub. You can help the ETHW by expanding it.Shintaro Uda published on the sensitive and highly-directional antenna they designed and constructed using closely-coupled parasitic elements. The antenna, which is effective in the higher-frequency ranges, has been important for radar, television, and amateur radio.
Yagi, Hidetsugu. U.S. Patent No. 1,860,123, "Variable Directional Electric Wave Generating Device", filed 3 September 1926.