Neutralization and unilateralization

ALTHOUGH various methods of neutralization have been employed for several years in vacuum-tube circuits,1 the unilateralization technique was introduced only recently. This technique is based on a study of the linear, active, four-terminal network theory, which has become increasingly important in the design of transistor circuitry. Although neutralized circuits are usually treated as conventional balanced-bridge circuits, they can be analyzed more systematically as network problems. This paper analyzes both neutralization and unilateralization circuitry by means of the four-terminal network theory, and clarifies the similarities and the differences between the two types of circuits. Typical examples of neutralized and unilateralized vacuum-tube and transistor amplifiers are also given.