Abstract
In this survey paper the various methods used to describe the electric-circuit properties of a transistor are reviewed. After a brief introduction and discussion of the low-frequency characterization of transistors and of the representation used for point-contact transistors, the remainder of the paper is devoted to the subject of high-frequency representation for junction transistors. The more popular equivalent circuits are described, and relations between parameters of different equivalent circuits are given. The alternative procedure of characterizing a transistor by its quadripole parameters (or matrix elements) as a function of frequency also is described, and advantages of this procedure are indicated. Throughout the paper a distinction is made between device parameters, or electrical parameters that can be related to the structure of the transistor as a device, independent of its circuit configuration, and circuit, or terminal, parameters, which correspond to relations between terminal voltages and currents. Included are references to approximately 90 papers representing the work of 60 authors.