In Berlin, Greinacher attended the lectures of Max Planck and received a doctorate in 1904 under Emil Warburg.

In 1912, Greinacher developed the magnetron and gave a fundamental mathematical description of this tube.

Greinacher was married twice: in 1910 to the German Marie Mahlmann, with whom he had two children, and then again in 1933 to Frieda Urben from Inkwil.

A foundation was established in Bern in 1988 with the name of Heinrich-Greinacher-Stiftung from the estate of the couple Frieda and Heinrich Greinacher.

Interest income of the Foundation's capital is used to fund the Heinrich Greinacher Prize and for the promotion of young researchers and scientists.