The Magnetron as a Generator of Centimeter Waves

168 BELL SYSTEM TECHNICAL JOURNAL operating life satisfactory? Could its efficiency and output power be substantially increased? Could one construct similar magnetrons at forty centimeters, at three centimeters, even at one centimeter? Could the magnetron oscillator be tuned conveniently? One by one, during the war years, all of these questions have been answered in the affirmative. In many instances, but not without detours and delays, results have been better than expected or hoped for. The British magnetron was first reproduced in America at the Bell Telephone Laboratories for use in its radar developments and those at the Radiation Laboratory of the National Defense Research Committee which was then being formed at the Massachusetts Institute of Technology. Since that time, extensive research and development work has been carried on in our Laboratories, in other industrial laboratories, and in the laboratories of the National Defense Research Committee., Several manufacturers have produced the resultant designs. Magnetron research and development was also carried on in Great Britain by governmental and industrial laboratories. There has been continuous interchange of information among all these laboratories through visits and written reports. Magnetron and radar developments have been greatly accelerated by this interchange. Multicavity magnetron oscillators are now available for use as pulsed and continuous wave generators at wavelengths from approximately 0.5 to 50 centimeters.