A new class of microwave and millimeter-wave amplifiers, called deflectron amplifiers, which are based on the deflection of low voltage electron beams in a microstructure were analyzed. This concept may be applied in two ways : as microelectronic amplifiers or as bunched beam cathodes to power conventional amplifier configurations such as klystrodes and traveling wave tubes. Estimates for gain and efficiency are obtained from a circuit analysis. Particle codes are used to test the viability of the concept. Frequencies of operation are projected up to a few tens of GHz for microelectronic amplifiers and up to approximately 80 GHZ for power amplifiers.