Klaas Posthumus

Fascinated by sound- and microwaves

The 22-year-old Klaas Posthumus graduated cum laude as an electrical engineer in 1924. He was immediately hired by Philips as an employee at the Philips Physical Laboratory in Eindhoven.

In the 1930s and 1940s, he worked on oscillator systems, radio receivers and amplifiers, among other things. He made his name by contributing to the development of the microwave oven. The special radio tube used had already been invented by A.W. Hull in 1921, but it was not until Posthumus that it was properly understood. The idea of using the microwave to heat food is thanks to him. His insight and inventiveness led to his promotion to director of the Philips Telecommunications Industry.

In 1970, the Technical University of Delft awarded Posthumus an honorary doctorate for his scientific work. When he died in 1990, more than 80 patents bore his name.