One of the attractive methods of generating an ultrashort electromagnetic pulse is based on stimulated emission from intense extended electron bunches. Radiation from such bunches may be considered as a classical analogue well known in quantum electronics as Dike's superradiance effect (SR). Superradiance of classical electrons may be associated with different mechanisms of stimulated emission (cyclotron, Cherenkov, bremsstrahlung etc). Different types of SR were recently observed experimentally at millimeter and centimeter wavelength bands. Progress in this research has enabled a new type of millimeter band generator to be created, which is capable of generating unique short (200-300 ps) electromagnetic pulses at super high peak powers exceeding 1 GW
