Masers for Radar Systems Applications

This paper is intended to provide the systems engineer with a practical introduction to the use of solid-state maser amplifiers in radars. Various environmental problems involved in the successful application of masers are discussed. An elementary survey of reflection-cavity and traveling-wave masers, together with some experimental results are presented. Another section treats the problem of saturation in masers and discusses some of the methods available for protecting masers from the TR leak-through pulses in radar. Progress made in the development of open-and closed-cycle liquid helium cryogenic systems suitable for masers is described. The authors' personal evaluations of the state of the art of ruby masers and closed-cycle helium refrigerators are given in appendixes.