Kinjiro Okabe (岡部 金治郎, Okabe Kinjirō; March 27, 1896 – April 8, 1984) was a Japanese electrical engineering researcher and professor who made major contributions to magnetron and radar development. He did work after the Second World War on medical instruments using ultrasounds.
Source: “Kinjiro Okabe”, English Wikipedia (CC BY-SA 4.0), excerpt