A review is presented of the theoretical studies on Hide-band microwav
e sources employing the stimulated Cherenkov radiation of relativistic
electron beams in a plasma waveguide, The motivation for such studies
lies in recent experiments on microwave plasma noise sources using in
tense relativistic electron beams. Although only theoretical problems
are discussed, all necessary estimates are obtained using parameter va
lues taken from actual General Physics Institute experiments, in part
already published. A very incomplete preliminary comparison of theoret
ical and experimental results is given.