Abstract
This paper presents a theory of resonant tunneling phenomena through a class of Symmetrical rectangular Double-Barrier structures(SDB's). We derive analycal form of transmission coefficient and the resonance condition for general SDB's. We, then, define three types of SDB's, i.c.neutral, repulsive, and attractive SDB's, among which this paper deals mainly with repulsive SDB's. Investigation of the resonance condition reveals that repulsive SDB's have similar resonance characteristics to neutral ones, but those of attractive SDB's are quite different. For repulsive SDB's, we discuss upper and lower bounds of each resonant energy level.
