The high-power pulsed magnetron: development and design for radar applications
The paper gives a general picture of the development of the multiple-circuit magnetron from the time of the first manufactured design up to the present day. The principles underlying magnetron design and operation are given as fully as space permits and detailed constructional features are discussed where they are of particular interest.The manufacture and performance of the earliest types is dealt with first. The use of the technique of “strapping” is then discussed, the effect on the resonance characteristics of the magnetron block being described. Further Sections deal with the mechanism of oscillation, and the calculation of operating performance.After summarizing the performance of the established types operating in the 10-cm wavelength range, the difficulties experienced in the design of valves for shorter wavelengths are outlined. Various constructional techniques for these valves are mentioned, together with the apparatus necessary to ensure that a finished valve shall operate with correct electrical characteristics.Further Sections deal with valves capable of generating the highest powers at wavelengths of 10 and 3 cm, and examples of finished designs are given. The fundamental difficulty of “mode change” is described, and a later Section discusses the method which has been evolved for estimating the mode-change performance of a given magnetron.The design of cathodes for magnetrons presents some unusual problems and these are discussed in detail.Finally, an appendix deals with some aspects of magnetron-circuit design using equivalent circuits.