The Theory of Electron Cyclotron Maser Devices

The electron cyclotron maser (gyrotron) is an extremely promising device for efficiently generating coherent, high-power millimeter and sub-millimeter radiation. This paper describes the physical mechanism of the maser as well as the recent theoretical progress made in dramatically a) enhancing the maser efficiency by contouring the external magnetic field and b) increasing the operating bandwidth in the slow wave maser amplifier by employing a dielectrically loaded waveguide.