AN ANALYSIS OF FEA NOISE MECHANISMS

摘要

Noise, due to spontaneous fluctuations in the electron beam, has long been a source of concern for power tube amplifiers and other applications. Whereas shot noise is due to the discrete nature of electron charge, flicker noise is related to ion bombardment, desorption of materials, diffusion and / or evaporation of low work function coatings or higher work function adsorbates. The time scale of shot noise is short by comparison to those associated with flicker noise. In the present work, an analysis and comparison of shot and flicker noise is made for field emitter arrays, focusing on characteristic emission times and their relative importance in rf applications. Diffusion models of Flicker noise are reviewed and examined in light of a statistical hyperbolic emission model. The mechanisms are considered in relation to experimental data taken on Spindt-type field emitters coated with zirconium carbide (ZrC).