Electronic Excitation of Cavity Oscillations

Abstract

A resonator is an essential device for sustained oscillations, such as a triode oscillator, in which the oscillating current is controlled by a resonant LC load. In microwave oscillators a cavity resonator controls the electronic current to sustain oscillation in the feedback mechanism. The electronic current density j can interact with a cavity when passing through an area dominated by the E vector. Either from electrons traveling to the cavity or in the opposite direction, the transferred energy operates the device like an oscillator or an electron accelerator. Sharing a similar principle, a betatron accelerator is operated at low frequencies for accelerating electrons by an alternating dynamic E field that arises from a sinusoidal magnetic flux.