Analysis of the LSA mode including effects of space charge and intervalley transfer time

A theoretical analysis is presented of the effects of intervalley transfer time, travel of an accumulation layer, and dipole domain growth upon LSA mode operation of GaAs devices. A modified two-valley model is used with energy relaxiation effects included to analyze a crystal divided into an active section (above threshold electric field) and a passive section (below threshold field) by an accumulation layer. Domain growth occurs in the active section. Specific results are given for crystal lengths of 20 µm and 100 µm and the influence of crystal parameters and operating conditions upon the conversion efficiency and devices RF admittance is discussed.