Magnetron Development

Radar (Radio Detection and Ranging) was first developed in Britain in the 1930s. This online exhibition looks at the scientists and engineers behind the development of radar during World War Two.

After that first successful demonstration, the magnetron was developed by Dr E C S Megaw and his team at the GEC Laboratories, Wembley. They transformed the magnetron from a laboratory device needing vacuum pumps and a large electromagnet to a workable, lightweight prototype.

Diagram of the internal structure of a magnetron

The cavity magnetron became the preferred source of very high frequency radio waves in radar devices. In fact it is still in use today: as the key component of a microwave oven.

For their work on the magnetron Randall and Boot were awarded the Thomas Gray Memorial Prize of the Royal Society of Arts in 1943 for 'improving the safety of life at sea'. Further recognition followed with an Award by the Royal Commission of Awards to Inventors (1949), the John Price Wetherill Medal of the Franklin Institute, Pennsylvania (1958) and the John Scott Award of the City of Philadelphia (1959).