Invention of a Temperature-Insensitive Quartz Oscillation Plate, 1933

In April 1933 Isaac Koga invented a temperature-insensitive quartz oscillation plate. This invention was used at first for radio transmitters and later for clocks, and has proven indispensable to all radio communication systems and much of information electronics. This achievement was approved as an IEEE Milestone, which was dedicated to Tokyo Institute of Technology in March 2017.