MILLIMETER-WAVELENGTH MASER AMPLIFIERS (REVIEW).

In this review authors examine the papers concerning millimeter-wave TW-PMA traveling wave-paramagnetic maser amplifiers published primarily in the 1970s. These studies were performed by several groups of researchers, working independently in the USSR, Sweden, and the USA. Authors discuss these studies when they discuss the separate problems and their solutions and when they describe the amplifiers as a whole. The following problems are included here: (1) the search for and study of the active material; (2) the development of electrodynamic systems allowing the active material to interact with the uhf field; (3) providing the conditions allowing for stable amplification; (4) the development of other functional elements, primarily pumping sources; and (5) the study of the performance characteristics of the amplifiers.