Analysis of microwave generation by field emitted electrons moving in crossed electric and magnetic fields

Abstract

A new microwave generating device is proposed and analysed theoretically. The device is based on the controlled motion of field emission (FE) electrons in a vacuum working space subject to crossed electric E and magnetic B fields. A cylindrical capacitor configuration is considered, the symmetry of the arrangement being cylindrical around the B axis whilst the radial electric field is applied between two co-axial surfaces. The electrons obtained from a FE cathode placed between these surfaces are shown to move on a cycloid-like trajectory. The high acceleration values of the electrons produced by the fields lead to significant electromagnetic radiation in the GHz range. The emitted power per electron and the frequency spectrum as functions of device model parameters are computed and several design suggestions are drawn.